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Environmental Science For Architects DOMESTIC DWELLING INVESTIGATION Cameron Worboys // Jonathan Ballard // Jonathon Hughes // Lidan Xiaopp


Preface Environmental science in architecture provides us with the means to understand the full life cycle of a building. Our architecture is not merely a finished construction but entails a complex system between occupants and the spaces they inhabit. The built environment is responsible for 40% of the UK’s carbon emissions. With the ever-increasing awareness and social pressures on reducing our carbon footprint, it is our responsibility as architects to address this complex subject first hand. This investigation explores four separate dwellings, in an attempt to analyse, evaluate and improve environmental performance within a functional domestic setting.


Contents 4

Methodology

5

Jonathan Ballard

Location & Initial Building Analysis Energy Bill Analysis Building Fabric analysis Ventilation Solar heat gains Internal heat gains Balance point Comparative HLC & Balance Points Degree-days & Carbon Emissions Conclusion

37

Lidan Xiao

General information Experience of each space Heat loss calculation Ventilation analysis Solar gain Internal heating and light gain Balance points & degree-days Conclusion

62

Cameron Worboys

Initial Building Analysis Building Fabric Analysis Ventilation Analysis Solar Gains Internal Heat Gains Balance Point Degree-Days Conclusion

90

Jonathon Hughes

Site Analysis Fabric Analysis Ventilation Analysis Solar Gains Internal Heat Gains Balance points Degree-days Conclusion

120

Individual Analysis Conclusion

122

Re-design

144

Conclusion

146

Equations

Layout & User Comfort PassivHaus Plans Cavity Wall Design Cavity Wall Design – Continued Roof/Ceiling Design Floor Design Openings Design Geometric Bridging Building Fabric Analysis Air Tightness Ventilation Solar Gains Internal Gains Balance Point Comparative HLC & Balance Points Degree-days & Carbon Emissions


4

Methodology The main aim of this investigation is to carry out a rigorous analysis of the building envelope to establish how the main components and factors of the building affect its performance and occupant comfort and how it operates within its immediate environment. The initial step will be to identify the location of the building and draw plans including areas, volumes and opening sizes. We will look at strengths and weaknesses in the current envelope. User observation of current issues and comfort levels will be recorded as a basis to begin the in depth investigation. This information can be used to quantify ways in which occupants can gain more control for greater comfort and efficiency. An energy/carbon audit will begin with the calculation of u-values and an examination of heat flow through the envelope. We will examine in detail the building fabric construction including walls, floor, roof, windows and doors, identifying any incidence of structural (homogenous and non-homogenous) and geometric bridging. This will enable us to calculate a Heat Loss Coefficient for each element of the building and identify weaknesses, which can be improved upon later.

 

Ventilation is essential to maintain good air quality by removal of pollutants and excess moisture, thereby providing occupants with a healthy environment. In summer it plays an important role in cooling. Our next step will be to examine the ventilation strategies operating in the building - stack, single-sided and cross-ventilation - to calculate a suitable air exchange rate. Using meteorological data we will be able to make adjustments for wind velocity and direction, terrain and height, and time of year to find a Heat Loss Coefficient for ventilation. This information will enable us to identify ways in which ventilation can be manipulated to provide optimum user comfort by mechanical, natural and/or hybrid systems. As part of heat flow analysis we will need to take into account heat gains. We will calculate solar gain taking into consideration location, orientation, solar inclination and solar flux. It will also be necessary to factor in internal heat gains - heat from lighting, appliances and metabolic gains. To calculate energy use we need to identify our balance point - the external temperature above which a building needs no further heating to achieve a constant internal comfort temperature. We will do this using total heat loss derived from HLC fabric and HLC ventilation factored against temperature changes. Calculating degree-days we can then estimate the amount of time needed to heat our houses over a period of time. We can use this information to understand actual heating costs and assess ways in which they can be reduced. The final part of this investigation is to calculate energy use and carbon emissions. This will enable us to assess the building’s performance and benchmark it against current best and future practice.

 


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A comprehensive environmental study into a modern detached converted barn, located in Beaconsfield, Buckinghamshire.

Initial Building Analysis

The studied building was completed in 2010. Previously “the barn” was a large two-storey workshop for use within the family business until permission was granted to convert it into a family home. The detached house is orientated north with large front façade windows to optimize sunlight into the main spaces. There is a large front garden, which houses covered car parking spaces. The house is set back 26m from the busy Beaconsfield high street and A40 (leading into the M40). Prevailing winds come the SE largely blocked by trees and buildings creating a sheltered site. Studied site and building outlined below

• • • • •

The building is a traditional oak frame construction using QPA grade beam timber. The frame is connected through traditional joinery methods aided with steel joining hangers. The façade is clad in treated English oak. Thick butt mineral wool insulation was added during construction sealed with a layer of radiant barrier foil insulation. Minimal privacy issues exist due to large fences and the properties distance from the main high street. Privacy issues are further reduced through glazing specification of distorted glass on main façade windows. There are a large variety of window sizes ranging for small skylights to large façade dominating windows. All windows are double glazed high performance mullion style windows manufactured by Velux and Borecco. Shutters are all artificial fully controlled by the occupant. Average comfort temperature is 20’c controlled by CRC thermostats. Overheating is not common even in summer months, mainly due to orientation of the building. The least pleasurable space is the downstairs bedroom receiving minimal light at the rear of the building and having poor views.

 


64

 

Ground Floor Average ceiling height: 3000mm Total floor area: 70.2 m2 3363

900,03

2082

2690

Entrance Lobby

Utility Room

1095

2082

Bathroom

1185

5720

1095

Kitchen

2789,38

3045

Bedroom 1

880

3880,81

Dining Room

3520

3750

920

1050

Comments: 1.1- Entrance Hall: The main entrance acts as a transitional space, minimising heat loss as the space externally exposed is limited. Used for storage of bikes and jackets. This creates a damp environment; this area is poorly ventilated, as there is no cross ventilation possibility. Thermostat for heating set at 20c . 1.2- Utility Room: Holds washing machine, tumble drier and the boiler (mega flow 750 electric boiler). Lack of windows creates a very dark space. REA electric panel provides heating for the house. 1.3- Bathroom: Downstairs bathroom no natural light, mechanically ventilated. If this breaks ventilation become very difficult. One radiator. 1.4- Kitchen and dining room: Very well lit and comfortable space two main radiators. Kitchen has a competent fan extractor above the cooker. Some heat escapes up stairwell, but the space never seems draughty. Oak wooden floors make the space feel colder. 1.5- Bedroom: Downstairs bedroom, two large windows lighting the space but neighbouring property construction blocks light. Bedroom is used intermittently due to corresponding to university breaks in winter and summer heating corresponds to this dates.

 


65

 

First Floor Average ceiling height: 2100mm Total floor area: 50.69 m2 4080

3092,17

Bedroom 2

2341,44

Bathroom

WorkBench/ Office

4859,38

842

1766,95

2347,72

Living Room

1050

6090

Comments: 2.1-Living Area: Skylights create a nice cosy space emphasised been the eves. Contains a thermostat for house heating control. 2.2- Study/ Workshop: Desk overlooks the outside space. Toxic smells from paints and varnishes when working on antiques are ventilated naturally through opening the window. 2.3- Bathroom: Directly above downstairs bathroom ventilates mechanically with the same system as the below bathroom. Natural light comes through south facing skylight. 2.4- Bedroom: Main master bedroom, single or double occupant room that is well light and well heated throughout the year due to full time occupancy.

 


66

 

Glazing Styles There are two different specifications of windows in the property for main composite wall windows and insulated roof skylights. • 5 Velux manufactured double glazed high performance centre pivot windows. • 9 Berecco argon filled double glazing units manufactured in a traditional mullion style. Tile batten Felt/breather membrane VELUX Transverse drainage gutter Support batten VELUX Underfelt collar BFX

A B

Installation batten VELUX Flashing EDW Top gutter

B

Vapour barrier

Internal finish

60

-1 5 25 0m m m m

A

Insulation

ELEVATION

SECTION A-A

Felt/breather membrane

80

20

m

m

m

m

VELUX Transverse drainage gutter VELUX Underfelt collar BFX

Gasket in window rebate Installation batten Chamfer VELUX Flashing EDW Pleated apron VELUX Underfelt collar BFX

VELUX Insulation frame BDX VELUX Vapour barrier BBX VELUX Lining LSB

Counter batten Felt/breather membrane

Purlin

VELUX Vapour barrier BBX

Sealed overlapping joint Vapour barrier

Energy Bill Observations The supply of energy comes (for planning reasons) come directly from the family shop located 20m away from the house. This energy is supplied ecotricity charged at 11.82p per KW/h. Energy bills are read off a separate energy meter in the house with an annual consumption is 6244 K/Wh per annum Hot Water system diagram The hot water/ heating system is supplied in a parallel circuit to radiators located under windows in key rooms.

 


67

  Building Fabric Analysis

Wall construction The main wall structure is made of a thick traditional timber stud wall measuring 310mm including internal plasterboard. The remaining thickness of the wall is external battens and a profiled oak clad. Working out the thermal resistance of the wall component will allow me to calculate the U-Value and find out how the wall performs thermally. Wall Construction Detail Drawing (not to scale) 1 2

3

4a

Path 1

5

6a

Path 2

6b 4b

Path 3 Path 4

7

Path 5

8

9a 9b

10 11

Path 6 Path 7

Path 8

1. Rsi- Internal Air Surface 2. Fermnal Plaster Board 3. Fermnal Plaster Board 4a. Air Gap (service void) 4b. Softwood Timber Batterns 5. Vapour control area 6a. High Performance Mineral Wool 6b. Timber Stud 7. Softwood Weather Boarding 8. Corovin Breather Membrane 9a. Battern Air Space 9b. Timber Batterns 10. Oak Timber Cladding (sealed) 11. Rso- External Air Surface

 


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Composite Wall Structure

Thermal Resistance (m 2 K/W)

25

Thermal Conductivity (w/mK) 0.4

100 %

25

0.4

0.0625

Air Gap (service void)

92%

25

-

0.180

4b

Softwood Timber Batterns

8%

25

0.13

0.1923

5

Vapour Control Layer

100%

12

0.12

0.1

6a 6b 7

Mineral Wool Timber Studs Softwood Weather Boarding

95% 5% 100%

200 200 20

0.038 0.13 0.14

5.2631 1.5384 0.1428

8

Corovin Breather Membrane

100%

5

0.2

0.025

9a.

Timber Battern Airspace

67.5%

38

-

0.180

9b. 10. 11.

Timber Batterns Oak Cladding Rso

32.5% 100% 100%

38 15 -

0.13 0.18 -

0.2923 0.0833 0.040

Layer

Material

Proportion of Surface Area

Thickness (mm)

1 2

Rsi Plaster Board

100 %

3

Plaster Board

4a

0.12 0.0625

To work out a weighted U-Value for the wall we firstly identify possible thermal paths through the structure. The highlighted red numbers identify the calculation of possible thermal bridges. Calculation of upper resistance limit (Values taken from CIBSE Guid A, Calculated using equation 1) Path Fractional area of material surface layer, F 1 100 100 100 100 100 100 100 100

1 2 3 4 5 6 7 8

F/R Total 1/Total= Ruppe r

2 3 100 92 100 92 100 8 100 8 100 92 100 8 100 8 100 92 0.1749 5.7175m2K/W

4 100 100 100 100 100 100 100 100

5 95 5 95 95 95 5 5 5

6 100 100 100 100 100 100 100 100

7 100 100 100 100 100 100 100 100

8 67.5 67.5 67.5 32.5 32.5 67.5 32.5 32.5

9 100 100 100 100 100 100 100 100

F total

Total resistance R

F/R

0.5899 0.0310 0.0513 0.0247 0.2840 0.0027 0.0013 0.0149

6.2592 2.5345 6.2715 6.3435 6.3715 2.5468 2.4913 2.6465

0.0942 0.0122 0.0082 0.0039 0.0445 0.0011 0.0052 0.0056

Lower Resistance Limit After the upper resistance limit is calculated the lower resistance limit is calculated using the “equation 2” Layer

Fractional Area, F

Thermal resistance per path, R (m2K/W)

F/R

Total F/R

1/Total F/R (m 2 K/W)

4a 4b

92 8

0.180 0.1923

5.111 0.4161

5.5271

0.1809

6a 6b

95 5

5.2631 1.5384

0.1805 0.325

0.5055

1.9782

9a 9b

67.5

3.75 1.1119

4.8619

0.2056

0.180 32.5

0.2923

Rlower is equal to the total of all the resistances in the cut section. Layer Material Thermal Resistance (m2K/W) Rsi 0.12 1 Plaster Board 0.0625 2 Plaster Board 0.0625 3 Timber Batterns and Air Void 0.1809 4 Vapour Control Layer 0.1 5 Mineral Wool Insulation & Timber studs 1.9782 6 Softwood Weather Boarding 0.1428 7 Corovin Breather Membrane 0.025 8 Timber batterns & airspace 0.2056 9 Oak Cladding 0.0833 10 Rso 0.040 11 Rtotal

3.0008

 


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Calculating The Total U-Value for Composite Wall Rupper= 5.7175 Rlower= 3.0008 Rtotal equation = 5.7175+3.0008/2 Rtotal= 4.3591 U Value = 1/ 4.3591 U-Value = 0.2294 The U-Value of 0.2294 shows good thermal performance of the wall structure. However within the nature traditional timber structure builds large amounts of thermal bridging occur pushing up the wall U-Value compared to that if there were only one homogenous thermal path through the structure assuming no thermal bridging When working out the homogenous value = Rtotal of path 1 = 6.2592 U Value= 1/Rtotal =1/6.2592 =0.1598 considerably lower than the bridged construction value, which would fall into passiv haus guidelines however in reality the value is unrealistic. Ceiling and Roof Analysis The barn construction typology means all first floor space is under an insulated pitched roof. As all elements of the wall construction are all incorporated the structure, the U-Value is calculated as a non-homogenous layer. Not to scale

Rsi Plaster Board Rafter Mineral Wool Insulation

Bitumen Sarking Felt Vertical Batten Horizontal Batten Clay Tiles Ventilated Void Rso

Integrated Pitched Insulated Roof becomes fully ventilated above the bitumen sarking felt. Illustrated by this line. A Rso for still air is used to calculate the U-Value for this section

Roof Structure Plan Cutaway

Path 1

Path 2

1

2

3a

4

5

3b

 


 

70

Insulated Pitched Roof Specification Layer

Material

Proportion of surface area

Thickness (mm)

1 2 3a 3b 4 5

Rsi Plasterboard Mineral Wool Insulation Oak Rafter Bitumen Sarking Felt Rso (still air)

100% 100% 76% 24% 100% 100%

50 250 250 35 -

Thermal Conductivity (W/mK) 0.4 0.038 0.18 0.19 -

Thermal Resistance, R (m 2 K/W) 0.1 0.125 6.5789 1.3888 0.1842 0.4

Calculating Upper Resistance Limit (Values taken from OBSE Guide A, calculated using equation 1) Path Fractional area of material surface layer, F

1 2

1 100 100

2 100 100 0.212 4.7169

F/R Total 1/Total= Ruppe r

3 76 24

4 100 100

5 100 100

F total

Total resistance R

F/R

0.76 0.24

7.3881 2.198

0.1029 0.1091

Calculating Lower Resistance Limit (Calculated using equation 2) Layer Fractional Area, F Thermal resistance per path, R (m2K/W) 3a 76 6.5789 3b 24 1.3888

F/R 0.0116 0.0173

Total F/R 0.0289

1/Total =Rlowe r (m 2 K/W) 3.4602

Rlower is equal to the total of all the resistances in the cut section. Layer 1 2 3 4 5 Rtotal

Thermal Resistance (m 2 K/W) 0.1 0.125 3.4602 0.1842 0.4

Material Rsi Plaster Board Mineral Wool and Rafters Bitumen Sarking Felt Rso (still air 4.2694

Calculating U-Value Rtotal = Rupper + Rlower / 2 = 4.7169 + 4.2694 / 2 = 4.4932 Rtotal U-Value = 1/ Rtotal = 1/ 4.4932 U-Value= 0.223 The roof structure has a very a low U-value. The large amount of insulation is responsible for this coupled with less thermal bridging within the structure. Compared to the wall structure the roof has slightly lower U-Value. However both U-Values are relatively low and considered OK under SAP guidelines and will do a good job in reducing carbon emissions from the building. Windows (external wall and skylight) Window Type Velux Roof Skylight Berecco Mullion Window

No. in Property 5 9

Thermal Resistance (m 2 K/W) 0.9

U-Value =1/Rtotal (W/m2K) 1.4 1.111

All Bereco products are designed with 24mm double- glazed soft-coated glazing units. Low E argon filled float glass comes standard. Ground Floor (All floor calculations using equation 4) Perimeter (m) Area (m 2 ) 34.756 70.2

First Floor

Perimeter (m) 22.936

P/A (m/m 2 ) 0.495

Area (m2) 47.84

U-Value(W/m 2 K)-

Thermal Resistance (m 2 K/W) 1.5 0.32

U-Value(W/m2K)-

Thermal Resistance (m 2 K/W) 2 0.27

P/A (m/m2) 0.479

Openings & Doors Quoted from timber frame design specification, English heritage homes LTD. U-Value Openings Oak Framed Doors

1.96 1.32

 


71

Geometric Bridging To complete the calculation of the total HLC for the dwelling the sum of all geometrical bridges needs to be calculated. Ground Floor Front North 1 Floor Ceiling Corners Front East 2 Floor Ceiling Corners Front North 3 Floor Ceiling Corners Side East 4 Floor Ceiling Corners Back South 5 Floor Ceiling Corners Side West 6 Floor Ceiling Corners

Linear Transmittance ϕ

Length of bridge L (mm)

(Lx ϕ linear thermal transmittance)

0.16 0.07 0.09

7270 7270 3000

1.163 0.508 0.27

0.08 0.07 0.09

1200 1200 3000

0.096 0.084 0.27

0.16 0.07 0.09

2890 2890 3000

0.462 0.202 0.27

0.16 0.07 0.09

4030 4030 3000

0.645 0.301 0.27

0.16 0.07 0.09

9851 9851 3000

1.577 0.689 0.27

0.16 0.07 0.09

7305 7305 3000

1.168 0.511 0.27 Total Ground Floor Htb

First Floor Front North 1 Intermediate Floor Eaves Rafter Insulated Corners Front East 2 Intermediate Floor Eaves Rafter Insulated Corners Front North 3 Intermediate Floor Eaves Rafter Insulated Corners Side East 4 Intermediate Floor Eaves Rafter Insulated Corners Back South 5 Intermediate Floor Eaves Rafter Insulated Corners Side West 6 Intermediate Floor Eaves Rafter Insulated Corners

9.026

Linear Transmittance ϕ

Length of bridge L (mm)

(Lx ϕ linear thermal transmittance)

0.07 0.04 0.09

7270 7270 2100

0.508 0.291 0.189

0.07 0.04 0.09

1200 1200 2100

0.084 0.048 0.189

0.07 0.04 0.09

2890 2890 2100

0.202 0.116 0.189

0.07 0.04 0.09

4030 4030 2100

0.282 0.161 0.189

0.07 0.04 0.09

9851 9851 2100

0.689 0.394 0.189

0.07 0.04 0.09

7305 7305 2100

0.511 0.292 0.189 Total First Floor Htb

4.712 Total Htb = 13.738

 


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Heat Loss Coefficient- Fabric (Calculated using equation 5) U-Value (Wm 2 /K) Ground Floor 0.32 First Floor 0.27 Wall 0.2294 First Floor Walls 0.2294 Roof 0.223 Berecco Windows 1.111 Velux Skylights 1.4 Doors 1.32

Area (m 2 ) 70.2 47.84 104 25.76 87.72 12.04 1.65 2.25

HLC (UxA) (W/K) 22.47 12.92 23.86 5.91 19.56 13.24 2.31 2.97

Heat lose geometric bridging 5.11 2.276 1.62 1.134 1.302 -

HLC total (W/K) 27.58 15.196 25.48 7.044 20.862 13.24 2.31 2.97 HLC fabric total=114.682

Building Fabric Analysis

160 140 120 100 80

HLc (W/K)

60

Area m2

40 20 0 Floor

Wall

Roof

Brecco Velux Windows Skyights

Doors

The graph compares the area of each component relative to the HLC. The graph shows that the building fabric is performing very well relative to the areas of the spaces. Perhaps the most successful element of the construction is the roof. The roof structure in timber frame is usually very susceptible to large heat loss through bridging but in the case the successful design of a modern timber frame structure has prevented this from occurred and a super insulation strategy within the fabric has worked well. The calculated U-Values for the fabric are low compared to the majority of buildings but fall short of passiv house guidelines. With the implication of interior insulation plasterboard the value may fall into passiv haus guidelines. The attempted reduction in U-Value through two layers of plasterboard was relatively unsuccessful compared alternative options available. However when the cost of such design implication is calculated, it may not be worth the about of energy consumption saved. These low HLC values so the relatively easy successful implication of eco friendly timber frame structures.

Ventilation Analysis

Ventilation plays key part in any buildings occupant success. Successful ventilation maintains healthy air quality for all occupants through the recycling of oxygen, its removes pollutants, condensation and importantly during hotter periods ventilation is the main component in cooling the building to a desired comfort temperature. Building regulations state there must be a minimum ventilation rate of 0.3l/s per m2 for domestic dwellings. Table 5.1b(part F of building regulations) states that the suggested SASR (l/s pers) for a two-bedroom dwelling is 17 l/s pers. Using a minimum ventilation rate of 0.3l/s factoring in the size of the dwelling a SASR of 27.4215 l/s is calculated. Volume flow rate is based on the number of occupants in the dwelling. In this case 3 occupants are used in the calculation using q= N x SASR/1000. Volume flow rate= 0.0823m3/s This air exchange rate can then be calculated from the volume flow rate using the calculation; n=q x 3600/ v Air exchange rate (arch-1) =1.344 arch-1 Knowing the minimum air exchange rate within the dwelling it is possible to calculate the HLCventilation for the dwelling using the equation; HLCventilation= 1/3 x n x v HLC ventilation = 1/3 x 1.344 x 220.49 HLCventilation = 98.779 w/k

 


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HLC for heating months (September-May) For heating months it is assumed that the majority of windows leading to wind driven ventilation will be closed. As a result a low air exchange rate is used in HLCventilation calculations. Each room’s volume is taken into consideration and a total HLC for ventilation during this period is calculated. For mechanically ventilated spaces such as bathrooms and the utility room an air exchange rate is calculated using data tables from (Szokolay introduction to architectural science.) (Calculated using equation 10) Ach- 1 1.344 1.344 2.6 1.344 2.6 1.344 1.344 2.6 2

Kitchen/Dining Room Entrance Hall Utility Room Bedroom Downstairs Downstairs Bathroom Living Room Bedroom 2 Upstairs Bathroom Hallway/Stairs

Vm 3 61.776 27.643 17.114 40.973 25.437 68.344 27.754 9.095 17.16

HLC (W/K) 27.676 12.384 14.832 18.356 22.045 30.618 12.434 7.8823 11.44 HLC Total = 157.6673

HLCventilation = 1/3 x n x v Meteorological Data Correction Cooling Months (June-August) To analyse a building’s ventilation within the cooling months meteorological data must be corrected for the calculations. Calculating a corrected wind speed value taking into consideration building height, air viscosity, surface roughness and average wind speeds allows us to achieve more accurate air exchange rate and subsequent HLC values. This is calculated through V z or r = V m x K x Z a All ventilation calculations taken for the cooling period show maximum ventilation rates using values for all windows, and at maximum opening.

Summer

Winter

(Calculated using equation 13) Month Wind Angle Deg June 270 July 270 August 270

Wind Speed (km/h) 16.668 18.504 16.668

Wind Speed (knots) 9 10 9

Wind Speed ms-1 4.63 5.14 4.63

Velocity corrected for the terrain and height of building; June July August

Vm 4.63 5.14 4.63

K(cp) 0.35 0.35 0.35

Za 5.5 5.5 5.5

0.25 0.25 0.25

Vr 2.482 2.755 2.482

 


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Single Sided Ventilation- June & August (Using Equations 9,10,11) Room

Window

Kitchen Dining Room Lobby Bedroom

A B C A A B A

Hall/ Stairs

Effective Width (m) 1.03 1.03 1.1 0.903 0.82 1.05 0.88

Height (m) 0.3 0.3 0.6 0.92 0.7 0.8 0.3

True Area (m 2 ) 0.309 0.309 0.66 0.856 0.574 0.84 0.264

Compound Coefficient

0.025

Vr

Q wind

2.482

0.019 0.019 0.041 0.053 0.036 0.052 0.016

Arch- 1

Q wind per room 0.079

Volume (m 3 ) 61.776

4.604

HLC (W/K) 94.80

0.053 0.088

27.643 40.973

6.902 7.732

63.59 105.6

0.016

17.16

3.356

19.19

Total HLC = 283.18 W/K

Single Sided Ventilation-July (Using Equations 9,10,11) Room

Window

Kitchen Dining Room Lobby Bedroom

A B C A A B A

Hall/ Stairs

Effective Width (m) 1.03 1.03 1.1 0.903 0.82 1.05 0.88

Height (m) 0.3 0.3 0.6 0.92 0.7 0.8 0.3

True Area (m 2 ) 0.309 0.309 0.66 0.856 0.574 0.84 0.264

Compound Coefficient

0.025

Vr

Q wind

2.755

0.021 0.021 0.045 0.059 0.039 0.057 0.018

Arch- 1

Q wind per room 0.087

Volume (m 3 ) 61.776

5.069

HLC (W/K) 104.4

0.059 0.096

27.643 40.973

7.684 8.435

70.81 115.2

0.018

17.16

3.776

21.59

Total HLC = 312 W/K

HLC –June & August = 283.18 W/K HLC- July = 312 W/K Cross Ventilation First Floor June-August For cross ventilation purposes the V r between June-August has been averaged and then calculated assuming the illustrated cross ventilation paths with a predominant south facing wind direction.

 


75

 

Living Space (Calculated using equations 10, 18 & 19)

Cd

0.6

Aw Vr Cp Cp 0.5 Volume m3

0.1967 2.6185 0.3 0.54772 68.344

Qwind Ach -1 HLC W/K

0.1693 8.9178 203.159

Total Opening Area Area 2 1/Area Total 1/Total Sq root

A1 0.228 x 3= 0.684

A2 0.144 X 2 =0.288

0.467 2.141 25.824 0.0387 0.1967

0.0829 12.062

A1

A2 0.228

Bedroom Upstairs (Calculated using equations 10, 18 & 19)

Cd

0.6

Aw Vr Cp Cp 0.5 Volume m3

0.2176 2.6185 0.3 0.54772 27.754

Qwind Ach -1 HLC W/K

0.18724 24.287 224.687

Total Opening Area Area 2 1/Area Total 1/Total Sq root

0.735

0.5402 1.8512 21.1182 0.04735 0.2176

0.0519 19.267

Heat Loss Co-efficient Total Heating Period( September- May) 157.6673

Cooling Period (June & August) 711.026

Cooling Period (June & August) Corrected 355.513

Cooling Period (June & August) Corrected 739.846

Cooling Period (July) Corrected 369.923

All of the calculations for the cooling period assume that all of the windows are open, for the whole period of each analysed month. As a result this produces an extreme situation HLC (maximum value). In reality the window opening will depend on where the occupant is located. i.e. when you occupy a space you control the ventilation through the opening of windows this tends to be restricted to only the space you currently occupy. As a result of this the cooling HLC is overstated an estimation value of 346.468 is given taking a 50% reduction in the HLC total (this is still a very high value for the occupant behaviour in my home.) This dramatically affects the average HLC ventilation and will have the resultant effect of overstating the energy consumption in the building.

Solar Gains

For solar gain analysis all 4 facades were taken as illustrated below;

 


76

 

Values for Svertical were calculated on the 4 illustrated facades using the spreadsheet. (converting horizontal to vertical flux) Representative Latitude (.N) 51.5

Buildings Latitude (.N) 51.6

Solar Radiation on the Horizontal (W/m2) June July

August

214

177

204

(Calculations using equation 16) Façade North 0. Façade East -90. Month Svertical Month Svertical (m) W/m 2 (m) W/m 2 Jan 10.72641674 Jan 19.87256466 Feb 20.35879704 Feb 38.51867736 March 33.30872704 March 61.56524736 April 54.639576 April 91.409784 May 75.2159916 May 111.2196844 June 91.97853536 June 122.9558742 July 85.34413644 July 117.784192 Aug 67.65654372 Aug 104.9219255 Sep 41.085141 Sep 73.603769 Oct 24.81434852 Oct 46.90850868 Nov 13.21801668 Nov 24.70675812 Dec 8.94448464 Dec 16.39290576

Façade South -180. Month Svertical (m) W/m 2 Jan 47.3233189 Feb 77.1832044 March 94.2460544 April 105.11436 May 108.549926 June 114.5726896 July 110.5232934 Aug 107.4132542 Sep 99.990985 Oct 85.2918322 Nov 56.0693298 Dec 40.8904104

Calculations using values from CIBSE Guide A, table 6b & 6d Solar Solar access Façade Transmittance Winter

Façade West 90. Month Svertical (m) W/m 2 Jan 19.87256466 Feb 38.51867736 March 61.56524736 April 91.409784 May 111.2196844 June 122.9558742 July 117.784192 Aug 104.9219255 Sep 73.603769 Oct 46.90850868 Nov 24.70675812 Dec 16.39290576

Solar Access Summer

Opening Area(m)

Frame Factor

Kitchen.1

N

0.63

1

1

0.876

0.7

Kitchen.2 Dining Room.1

N

0.63

1

1

0.876

0.7

N

0.63

1

1

2.9625

0.7

Hallway.1

N

0.63

0.77

0.9

1.936

0.7

Hallway.2

S

0.63

0.54

0.7

0.228

0.7

Lobby.1 Living Room.1 Living Room.2 Living Room.3 Living Room.4

N

0.63

0.3

0.5

1.08

0.7

N

0.63

1

1

0.9262

0.7

N

0.63

1

1

0.3976

0.7

N

0.63

1

1

0.3976

0.7

S

0.63

1

1

0.228

0.7

Bathroom.1

S

0.63

1

1

0.228

0.7

Bedroom.1

W

0.63

0.54

0.7

1.104

0.7

Bedroom.2

W

0.63

0.3

0.5

1.26

0.7

Bedroom.3.

S

0.63

1

1

0.228

0.7

Bedroom.4

E

0.63

0.3

0.5

1.2

0.7

Ground Floor Solar Calculations (Heating Period) (Calculated using the spreadsheet “Calculating solar gains”.) Jan Feb March April May Sep Oct Nov Dec

Kitchen.1

Kitchen.2

Dining Room.1

Hallway.1

Hallway.2

Lobby.1

Bedroom.1

Bedroom.2

3.729407768

3.729407768

12.61229511

6.346464325

2.312516823

1.379369997

4.702164852

2.981445105

7.078436134

7.078436134

23.93820439

12.04562365

3.771659782

2.618051721

9.114131664

5.778887831

11.58092478

11.58092478

39.16494252

19.70766687

4.605458607

4.283355739

14.56731666

9.236523244

18.9973282

18.9973282

64.24610135

32.32842134

5.136552793

7.026409059

21.62900868

13.71404536

26.15142691

26.15142691

88.44018518

44.50280265

5.304436288

9.672445569

26.31634617

16.68608906

14.2846626

14.2846626

48.30857642

24.30871259

4.88619227

5.283368358

17.41582234

11.04264098

8.627561877

8.627561877

29.17711422

14.68182539

4.167898648

3.191016037

11.09929919

7.037599122

4.595698199

4.595698199

15.54195881

7.820661208

2.739902261

1.699778786

5.846011907

3.706710449

3.109857775

3.109857775

10.51707039

5.292154318

1.998164207

1.150221369

3.878822216

2.459398144

 


77

 

First Floor Solar Calculation (Heating Period) (Calculated using the spreadsheet “Calculating solar gains”.) Living Room.1 Jan Feb March April May Sep Oct Nov Dec

Jan Feb March April May Sep Oct Nov Dec

Living Room.2

Living Room.3

Living Room.4

Bathroom.1

Bedroom.3

Bedroom.4

3.943124972

1.692708366

1.692708366

7.467971808

7.467971808

4.282438562

6.761745098

7.484072542

3.212769642

3.212769642

12.1800839

12.1800839

6.984555152

11.02824498

12.24458051

5.256364944

5.256364944

14.87272857

14.87272857

8.52862705

13.46625324

20.08598787

8.622531611

8.622531611

16.58782806

16.58782806

9.512134802

15.01916021

27.65005891

11.86964308

11.86964308

17.12998593

17.12998593

9.823030164

15.51004763

15.10325856

6.483540923

6.483540923

15.77932137

15.77932137

9.048504204

14.2871119

9.121972386

3.915888815

3.915888815

13.45968569

13.45968569

7.71833083

12.18683815

4.859058986

2.085901374

2.085901374

8.848157398

8.848157398

5.073893075

8.011410119

3.288071086

1.411506223

1.411506223

6.452810986

6.452810986

3.700304086

5.8425854

Total Downstairs

Total Upstairs

Total Qsolar (Heating Period)

37.79307175

33.30866898

71.10174073

71.4234313

56.28257975

127.7060111

114.7271132

74.49764784

189.224761

182.075195

95.03800223

277.1131972

243.2251587

110.9823947

354.2075535

139.8146381

82.96459924

222.7792374

86.60987636

63.77829038

150.3881667

46.54641981

39.81247973

86.35889954

31.51554619

28.55959499

60.07514118 Q solar (w) 1538.954708

Ground Floor Calculations (Cooling period) (Calculated using the spreadsheet “Calculating solar gains”.) Dining Kitchen.1 Kitchen.2 Room.1 Hallway.1 June 31.97950188 31.97950188 108.1498565 63.60854346 July 29.67282487 29.67282487 100.3490225 59.0204681 Aug 23.52312481 23.52312481 79.55166352 46.78846195

Hallway.2

Lobby.1

Bedroom.1

Bedroom.2

7.25763452

19.71339157

37.71355692

30.74474749

7.001124546

18.29146739

36.12727619

29.45158385

6.804118366

14.50055639

32.18210625

26.2354127

First Floor Calculations (Cooling Period) (Calculated using the spreadsheet “Calculating solar gains”.) Living Living Living Room.1 Room.2 Room.3 June 33.81211717 14.5148972 14.5148972 July 31.37325388 13.46793969 13.46793969 Aug 24.8711395 10.67670596 10.67670596

Living Room.4

Bathroom.1

Bedroom.3

Bedroom.4

18.08042284

18.08042284

10.36804931

29.28071188

17.44139799

17.44139799

10.00160649

28.04912748

16.95061067

16.95061067

9.720169095

24.98610734

Total Qsolar totals (cooling periods) June July Aug

Total Downstairs

Total Upstairs

Total Q solar (cooling period)

331.1467342

138.6515184

469.7982527

309.5865923

131.2426632

440.8292555

253.1085688

114.8320492

367.940618 Total Qsolar (w)- 1278.568126

 


 

78

Monthly Solar Gain Per Room 120

100 Jan Feb 80

March April May

60

June July Aug

40

Sep Oct Nov

20

Dec

0 Kitchen

Dining Room

Hallway

Lobby

Bedroom Living Room Bathroom

Bedroom

Solar gains in general are quite low this is due to predominately north facing aspect of windows. Where windows are exposed to south facing aspect the area of exposed window is small such as with skylights thus producing the low solar gain figure.

Internal Heat Gains

Lighting Gains A yearly for the lighting time has been taken to accommodate for the more intense use in winter than in summer. (Calculations using equations 14) Light Type

No.fittings

Power (w)

Total power (w)

Time (s)

Energy (J)

1

20

20

1800

36000

Utility Room

Spiral 100w eq. GU10 compact flourescent

3

7

21

360

7560

Kitchen

GU10 Halogen

5

50

250

7200

1800000

Dining Room

Spiral 60w eq.

2

11

22

21600

475200

Bathroom 1

GU10 Halogen GU10 compact flourescent GU10 compact flourescent

1

50

50

100

5000

3

7

21

200

4200

4

7

28

3600

100800

Spiral 60w eq. GU10 compact flourescent

2

11

22

28800

633600

4

7

28

14400

403200

2

50

100

14400

1440000

Bathroom 2

GU10 Halogen GU10 compact flourescent

2

7

14

2880

40320

Bedroom 2

Spiral 100w eq.

1

20

20

7200

144000

Lobby

Bedroom 1 Hallway Living Room Study

Total Energy (J) Q lighting (w)

5089880 58.910648

Appliance Gains (Calculations using equations 14, based on data provided by manufacturers where available) Kitchen

Appliance

Power (w)

Time (s)

Oven

1200

7200

Energy (J) 8640000

Fridge/freezer

500

86400

43200000

Dishwasher

1200

3600

4320000

Microwave

1000

300

300000

Kettle

3000

500

1500000

 


 

79 Bathroom 1 Bedroom 1 Lving Room

Study Bathroom 2 Bedroom 2

Utility Room

Hairdryer

1200

100

120000

Power Shower

240

420

100800

LED TV

80

900

72000

Laptop

30

10800

324000

LED TV

240

7200

1728000

Sky Box

50

86400

4320000

Ipod Speakers

60

900

54000

Desktop Computer

130

18000

2340000

Magnifying glass

50

3600

180000

Hairdrier

1200

100

120000

Power Shower

240

2800

672000

LED TV

240

3600

864000

Laptop

60

14400

864000

Speakers

100

200

20000

Washing Machine

500

1800

900000

Tumble Drier

4000

500

2000000

Total Energy

72638800

Q appliance (w)

840.7266

Metabolic Gains

(Calculations using equations 14) Occupant

Gain (W)

Time (S)

Metabolic Energy (J)

Male

115

21600

2484000

140

3600

504000

115

7200

828000

140

1800

252000

97.75

16200

1583550

Total Energy

5651550

Male Female

Q me tabolic (W) 65.411458

Internal Gain Analysis Total Q lighting (W)

58.910648

Q appliance (w)

840.7266

Q me tabolic (w)

65.411458

Q inte rnal (W)

965.048706

The large number of energy saving light bulbs has created a low Qlighting. This figure has been bought up dramatically by GU10 haolgen light bulbs in areas such as the kitchen accounting for just over 20% of the total Qlighting value, this suggested their immediate replacement with low energy equivalents. Despite our best efforts to maintain and eco friendly home the main energy consumption is coming from appliance use within the house, this figure being almost 15x large than Qlighting. Although low energy appliances are difficult to source and very expensive to replace, comparative to bulbs, our energy consumption could be greatly reduced by simple spending less time on these appliances. Due to the busy nature of the house the Qmetabolic is relatively low, the relatively small spaces within the dwelling are larger affected by metabolic gains especially in the living room. In reality this metabolic gain will be considerably lower as the student occupant lives there for under half a year when not at university.

 


80

  Balance Points

Heating Period (September-May) (Calculations using equation 12) To

Ti

Delta T

HLC (W/K)

Q total heat loss

-1

21

22

272.3493

5991.6846

Month Jan

-0.5

21

21.5

272.3493

5855.50995

Feb

0

21

21

272.3493

5719.3353

0.5

21

20.5

272.3493

5583.16065

1

21

20

272.3493

5446.986

March April

1.5

21

19.5

272.3493

5310.81135

May

2

21

19

272.3493

5174.6367

June

2.5

21

18.5

272.3493

5038.46205

3

21

18

272.3493

4902.2874

July

3.5

21

17.5

272.3493

4766.11275

Aug

4

21

17

272.3493

4629.9381

Sep

4.5

21

16.5

272.3493

4493.76345

Oct

5

21

16

272.3493

4357.5888

Nov

5.5

21

15.5

272.3493

4221.41415

6

21

15

272.3493

4085.2395

6.5

21

14.5

272.3493

3949.06485

7

21

14

272.3493

3812.8902

7.5

21

13.5

272.3493

3676.71555

8

21

13

272.3493

3540.5409

8.5

21

12.5

272.3493

3404.36625

9

21

12

272.3493

3268.1916

9.5

21

11.5

272.3493

3132.01695

10

21

11

272.3493

2995.8423

10.5

21

10.5

272.3493

2859.66765

11

21

10

272.3493

2723.493

11.5

21

9.5

272.3493

2587.31835

12

21

9

272.3493

2451.1437

12.5

21

8.5

272.3493

2314.96905

13

21

8

272.3493

2178.7944

13.5

21

7.5

272.3493

2042.61975

14

21

7

272.3493

1906.4451

14.5

21

6.5

272.3493

1770.27045

15

21

6

272.3493

1634.0958

15.5

21

5.5

272.3493

1497.92115

16

21

5

272.3493

1361.7465

16.5

21

4.5

272.3493

1225.57185

17

21

4

272.3493

1089.3972

17.5

21

3.5

272.3493

953.22255

18

21

3

272.3493

817.0479

18.5

21

2.5

272.3493

680.87325

19

21

2

272.3493

544.6986

19.5

21

1.5

272.3493

408.52395

20

21

1

272.3493

272.3493

20.5

21

0.5

272.3493

136.17465

21

21

0

272.3493

0

Dec

Qsolar

Qinternal

Qtotal Heat gain

71.10174073

965.048706

1036.150447

127.7060111

965.048706

1092.754717

189.224761

965.048706

1154.273467

277.1131972

965.048706

1242.161903

354.2075535

965.048706

1319.25626

469.7982527

965.048706

1382.286565

440.8292555

965.048706

1356.140525

367.940618

965.048706

1291.386994

222.7792374

965.048706

1187.827943

150.3881667

965.048706

1115.436873

86.35889954

965.048706

1051.407606

60.07514118

965.048706

1025.123847

 


81

 

Heating Period Monthly Balance Points (September – May) -1.00

Q total

Jan

Feb

March

April

May

Sep

Oct

Nov

Dec

5991.68

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

-0.50

5855.51

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

0.00

5719.34

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

0.50

5583.16

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

1.00

5446.99

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

1.50

5310.81

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

2.00

5174.64

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

2.50

5038.46

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

3.00

4902.29

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

3.50

4766.11

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

4.00

4629.94

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

4.50

4493.76

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

5.00

4357.59

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

5.50

4221.41

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

6.00

4085.24

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

6.50

3949.06

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

7.00

3812.89

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

7.50

3676.72

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

8.00

3540.54

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

8.50

3404.37

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

9.00

3268.19

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

9.50

3132.02

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

10.00

2995.84

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

10.50

2859.67

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

11.00

2723.49

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

11.50

2587.32

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

12.00

2451.14

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

12.50

2314.97

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

13.00

2178.79

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

13.50

2042.62

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

14.00

1906.45

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

14.50

1770.27

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

15.00

1634.10

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

15.50

1497.92

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

16.00

1361.75

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

16.50

1225.57

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

17.00

1089.40

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

17.50

953.22

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

18.00

817.05

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

18.50

680.87

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

19.00

544.70

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

19.50

408.52

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

20.00

272.35

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

20.50

136.17

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

21.00

0.00

1036.15

1092.75

1092.75

1242.16

1319.26

1187.83

1115.44

1051.41

1025.12

16.21

16.11

16.34

16.48

17.16

17.29

Balance Point c 17.22 16.89 16.51 Balance points read off graph below through excel

 


82

 

Balance Point Heating Period 7000.000

6000.000

5000.000

Qtotal Heat Loss Jan Feb

4000.000

March April May June July Aug

3000.000

Sep Oct Nov Dec

2000.000

1000.000

0.000 -10

0

10

20

30

40

50

 


83

 

Cooling Period (June & August)

Due to the dramatic changes in HLC between heating and cooling months, HLC incorporates a maximum HLC ve ntilation value as the taken ventilation flow rates were calculated assuming all windows fully open 50% of the time (although reduced from 100% this figure is overstated) (Calculations using equation 12) To

Ti

Delta T

HLC (W/K)

Q total heat loss

-1

21

22

470.195

10344.29

Month June

-0.5

21

21.5

470.195

10109.1925

July

0

21

21

470.195

9874.095

0.5

21

20.5

470.195

9638.9975

Aug

1

21

20

470.195

9403.9

1.5

21

19.5

470.195

9168.8025

2

21

19

470.195

8933.705

2.5

21

18.5

470.195

8698.6075

3

21

18

470.195

8463.51

3.5

21

17.5

470.195

8228.4125

4

21

17

470.195

7993.315

4.5

21

16.5

470.195

7758.2175

5

21

16

470.195

7523.12

5.5

21

15.5

470.195

7288.0225

6

21

15

470.195

7052.925

6.5

21

14.5

470.195

6817.8275

7

21

14

470.195

6582.73

7.5

21

13.5

470.195

6347.6325

8

21

13

470.195

6112.535

8.5

21

12.5

470.195

5877.4375

9

21

12

470.195

5642.34

9.5

21

11.5

470.195

5407.2425

10

21

11

470.195

5172.145

10.5

21

10.5

470.195

4937.0475

11

21

10

470.195

4701.95

11.5

21

9.5

470.195

4466.8525

12

21

9

470.195

4231.755

12.5

21

8.5

470.195

3996.6575

13

21

8

470.195

3761.56

13.5

21

7.5

470.195

3526.4625

14

21

7

470.195

3291.365

14.5

21

6.5

470.195

3056.2675

15

21

6

470.195

2821.17

15.5

21

5.5

470.195

2586.0725

16

21

5

470.195

2350.975

16.5

21

4.5

470.195

2115.8775

17

21

4

470.195

1880.78

17.5

21

3.5

470.195

1645.6825

18

21

3

470.195

1410.585

18.5

21

2.5

470.195

1175.4875

19

21

2

470.195

940.39

19.5

21

1.5

470.195

705.2925

20

21

1

470.195

470.195

20.5

21

0.5

470.195

235.0975

21

21

0

470.195

0

Qsolar

Qinternal

Qtotal Heat gain

469.7982527

965.048706

1382.286565

440.8292555

965.048706

1356.140525

367.940618

965.048706

1291.386994

 


84

 

Monthly Balance Points Cooling Period (June & August) Q total

June

August

-1.000

10344.29

1382.286565

1291.386994

-0.500

10109.1925

1382.286565

1291.386994

0.000

9874.095

1382.286565

1291.386994

0.500

9638.9975

1382.286565

1291.386994

1.000

9403.9

1382.286565

1291.386994

1.500

9168.8025

1382.286565

1291.386994

2.000

8933.705

1382.286565

1291.386994

2.500

8698.6075

1382.286565

1291.386994

3.000

8463.51

1382.286565

1291.386994

3.500

8228.4125

1382.286565

1291.386994

4.000

7993.315

1382.286565

1291.386994

4.500

7758.2175

1382.286565

1291.386994

5.000

7523.12

1382.286565

1291.386994

5.500

7288.0225

1382.286565

1291.386994

6.000

7052.925

1382.286565

1291.386994

6.500

6817.8275

1382.286565

1291.386994

7.000

6582.73

1382.286565

1291.386994

7.500

6347.6325

1382.286565

1291.386994

8.000

6112.535

1382.286565

1291.386994

8.500

5877.4375

1382.286565

1291.386994

9.000

5642.34

1382.286565

1291.386994

9.500

5407.2425

1382.286565

1291.386994

10.000

5172.145

1382.286565

1291.386994

10.500

4937.0475

1382.286565

1291.386994

11.000

4701.95

1382.286565

1291.386994

11.500

4466.8525

1382.286565

1291.386994

12.000

4231.755

1382.286565

1291.386994

12.500

3996.6575

1382.286565

1291.386994

13.000

3761.56

1382.286565

1291.386994

13.500

3526.4625

1382.286565

1291.386994

14.000

3291.365

1382.286565

1291.386994

14.500

3056.2675

1382.286565

1291.386994

15.000

2821.17

1382.286565

1291.386994

15.500

2586.0725

1382.286565

1291.386994

16.000

2350.975

1382.286565

1291.386994

16.500

2115.8775

1382.286565

1291.386994

17.000

1880.78

1382.286565

1291.386994

17.500

1645.6825

1382.286565

1291.386994

18.000

1410.585

1382.286565

1291.386994

18.500

1175.4875

1382.286565

1291.386994

19.000

940.39

1382.286565

1291.386994

19.500

705.2925

1382.286565

1291.386994

20.000

470.195

1382.286565

1291.386994

20.500

235.0975

1382.286565

1291.386994

21.000

0

1382.286565

1291.386994

Balance Point c 18.11 Balance points read off graph below through excel

18.24

 


85

 

Balance Point Cooling Period (June & August) 12000

10000

8000

Qtotal

6000

June August

4000

2000

0 -5

0

5

10

15

20

25

 


86

 

Cooling Period (July)

(Calculations using equation 12) To

Ti

Delta T

HLC (W/K)

Q total heat loss

-1

21

22

369.923

8138.306

-0.5

21

21.5

369.923

7953.3445

0

21

21

369.923

7768.383

0.5

21

20.5

369.923

7583.4215

1

21

20

369.923

7398.46

1.5

21

19.5

369.923

7213.4985

2

21

19

369.923

7028.537

2.5

21

18.5

369.923

6843.5755

3

21

18

369.923

6658.614

3.5

21

17.5

369.923

6473.6525

4

21

17

369.923

6288.691

4.5

21

16.5

369.923

6103.7295

5

21

16

369.923

5918.768

5.5

21

15.5

369.923

5733.8065

6

21

15

369.923

5548.845

6.5

21

14.5

369.923

5363.8835

7

21

14

369.923

5178.922

7.5

21

13.5

369.923

4993.9605

8

21

13

369.923

4808.999

8.5

21

12.5

369.923

4624.0375

9

21

12

369.923

4439.076

9.5

21

11.5

369.923

4254.1145

10

21

11

369.923

4069.153

10.5

21

10.5

369.923

3884.1915

11

21

10

369.923

3699.23

11.5

21

9.5

369.923

3514.2685

12

21

9

369.923

3329.307

12.5

21

8.5

369.923

3144.3455

13

21

8

369.923

2959.384

13.5

21

7.5

369.923

2774.4225

14

21

7

369.923

2589.461

14.5

21

6.5

369.923

2404.4995

15

21

6

369.923

2219.538

15.5

21

5.5

369.923

2034.5765

16

21

5

369.923

1849.615

16.5

21

4.5

369.923

1664.6535

17

21

4

369.923

1479.692

17.5

21

3.5

369.923

1294.7305

18

21

3

369.923

1109.769

18.5

21

2.5

369.923

924.8075

19

21

2

369.923

739.846

19.5

21

1.5

369.923

554.8845

20

21

1

369.923

369.923

20.5

21

0.5

369.923

184.9615

21

21

0

369.923

0

Month July

Qsolar

Qinternal

Qtotal Heat gain

440.8292555

965.048706

1356.140525

 


87

 

Monthly Balance Points Cooling Period (July) Qtotal

June

-1.000

8138.306

1356.140525

-0.500

7953.3445

1356.140525

0.000

7768.383

1356.140525

0.500

7583.4215

1356.140525

1.000

7398.46

1356.140525

1.500

7213.4985

1356.140525

2.000

7028.537

1356.140525

2.500

6843.5755

1356.140525

3.000

6658.614

1356.140525

3.500

6473.6525

1356.140525

4.000

6288.691

1356.140525

4.500

6103.7295

1356.140525

5.000

5918.768

1356.140525

5.500

5733.8065

1356.140525

6.000

5548.845

1356.140525

6.500

5363.8835

1356.140525

7.000

5178.922

1356.140525

7.500

4993.9605

1356.140525

8.000

4808.999

1356.140525

8.500

4624.0375

1356.140525

9.000

4439.076

1356.140525

9.500

4254.1145

1356.140525

10.000

4069.153

1356.140525

10.500

3884.1915

1356.140525

11.000

3699.23

1356.140525

11.500

3514.2685

1356.140525

12.000

3329.307

1356.140525

12.500

3144.3455

1356.140525

13.000

2959.384

1356.140525

13.500

2774.4225

1356.140525

14.000

2589.461

1356.140525

14.500

2404.4995

1356.140525

15.000

2219.538

1356.140525

15.500

2034.5765

1356.140525

16.000

1849.615

1356.140525

16.500

1664.6535

1356.140525

17.000

1479.692

1356.140525

17.500

1294.7305

1356.140525

18.000

1109.769

1356.140525

18.500

924.8075

1356.140525

19.000

739.846

1356.140525

19.500

554.8845

1356.140525

20.000

369.923

1356.140525

20.500

184.9615

1356.140525

21.000

0

1356.140525

Balance Point c 17.41 Balance point read off graph below through excel

 


88

 

Average annual balance point- 17.0016 Heating average balance point- 16.695 Cooling average balance point-17.92 This balance point is incredibly high compared to my expected balance point taking into account previous data from the investigation, this suggests despite ventilation flow rate being corrected in the our methodology by 50% this figure is still overstating considering my occupant habits.

Degree Days Month starting

14

14.5

15

15.5

16

16.5

17

17.5

18

18.5

19

19.5

20

01/01/2009

320

336

351

367

382

398

413

429

444

460

475

491

506

01/02/2009

250

264

278

292

306

320

334

348

362

376

390

404

418

01/03/2009

184

199

214

229

245

260

276

291

307

322

338

353

369

01/04/2009

92

104

116

129

142

156

170

184

198

213

228

242

257

01/05/2009

47

56

65

75

86

97

109

122

134

148

161

175

189

01/06/2009

17

22

27

34

40

47

55

64

72

82

92

102

113

01/07/2009

3

5

7

12

17

23

30

38

46

56

65

77

88

01/08/2009

4

6

8

10

13

17

22

28

36

44

52

62

72

01/09/2009

15

20

25

32

39

48

56

66

76

88

100

113

127

01/10/2009

62

74

86

99

112

126

140

155

170

186

201

216

232

01/11/2009

124

139

153

168

183

198

213

228

243

258

273

288

303

01/12/2009

298

313

329

344

360

375

391

406

422

437

453

468

484

01/01/2010

366

382

398

413

428

444

459

475

490

506

521

537

552

01/02/2010

280

294

308

322

336

350

364

378

392

406

420

434

448

01/03/2010

216

231

247

262

277

293

308

324

339

355

370

386

401

01/04/2010

123

135

147

160

173

187

200

215

229

243

258

273

288

01/05/2010

93

104

115

126

138

151

164

177

190

204

218

232

246

01/06/2010

16

20

25

31

37

44

51

59

67

76

85

95

105

01/07/2010

1

2

3

6

8

11

15

20

25

32

38

46

54

01/08/2010

10

14

18

23

29

36

43

51

60

71

81

93

105

01/09/2010

32

39

46

55

64

74

85

96

108

121

133

147

160

01/10/2010

95

107

119

133

146

160

175

190

205

220

235

251

266

01/11/2010

231

245

259

273

288

302

317

332

347

362

377

392

407

01/12/2010

390

405

421

436

452

467

483

498

514

529

545

560

576

01/01/2011

277

292

308

323

339

354

370

385

401

416

432

447

463

01/02/2011

187

201

215

229

243

257

271

285

299

313

327

341

355

01/03/2011

202

216

231

246

261

276

292

307

322

338

353

369

384

01/04/2011

64

74

83

94

104

115

127

139

151

163

176

189

202

01/05/2011

50

58

67

77

88

99

111

124

137

151

164

179

194

01/06/2011

28

35

42

50

58

68

77

88

99

110

123

135

148

01/07/2011

8

12

16

22

29

36

44

54

63

74

85

97

109

01/08/2011

8

12

16

22

28

36

44

54

64

75

86

98

110

01/09/2011

16

21

26

33

39

48

56

66

77

88

100

113

125

01/10/2011

57

66

74

85

95

108

120

134

147

162

176

191

206

01/11/2011

116

130

144

159

174

188

203

218

233

248

263

278

293

01/12/2011

216

231

247

262

278

293

309

324

340

355

371

386

402

2009

2010

2011

AVG

Balance Point

HLC

kWh

Jan

413

459

370

414

17.22

272.3493

2706.062645

Feb

334

364

271

323

16.89

272.3493

2111.251774

Mar

260

293

276

276.3333333

16.51

272.3493

1806.220558

Apr

142

173

104

139.6666667

16.21

272.3493

912.9148536

138

88

75.33333333

16.12

272.3493

492.4075344

May Jun

-

-

-

-

-

-

-

Jul

-

-

-

-

-

-

-

 


89 Aug

-

-

-

-

-

-

-

Sep

48

74

48

56.66666667

16.34

272.3493

370.395048

Oct

126

160

108

131.3333333

16.48

272.3493

858.4449936

Nov

213

317

203

244.3333333

17.16

272.3493

1597.056295

Dec

406

498

324

409.3333333

17.33

272.3493

2675.559523

Total kWh- 13530.31322 Total Energy

Emission factor

Boiler efficiency

Carbon emissions

13530.31322

0.19

0.93

2764.25754

Predicted Cost

426.2048666

Property Area

120.89

kWh/m2

111.9225182

Comparison with housing standards

Actual

New build

PassivHaus

0

20

40

60

80

100

120

Conclusion

The above graph shows the house’s total energy consumption per m2 of the dwelling. This shows that the building is highly outperformed by stated standards. This suggests that the building will need to be heated through the cooling period the majority of time. This figure could be high due to the aspect of the building. The predominately north facing building receives very little in the way of solar gains. Passiv Haus recommends optimising south facing aspects to increase solar gains within the building utilising the concept of natural heating to a designer’s advantage. In the case of my home the large fence the property is backed onto prevented this design implication. However due to the build date of 2010 this total energy consumption must have been lower to fall into new build guidelines. The fabric heat losses within the dwelling are very low falling well within the new built guidelines. This suggests that the main imperfect variable in the calculation method is HLC ventilation. As mentioned earlier this value was most likely overstated methodologically with a reduction in the ventilation flow rate of 50%. Taking into account occupant habits this value is more likely to be around 20-25% (as a maximum) during the cooling period (assuming all window opening are fully open) Through a change in the kWh/m2, to calculate a given reduction in the HLCventilation by around 50% (bringing ventilation flow rate to 25%), it can be estimated that the energy consumption would be around 55.961125 kWh/m2. This value falls within the new build guidelines. Existing energy bill information further backs up this estimation, as the total kWh would be reduced to an estimate of around 6765.15661 kWh and the energy bills for the house states a calculated consumption of 73804 kWh. The scope for renovation and improvement within this build depends on the calculations taken. Original energy calculations could easily be improved through an increase in the size of openings to increase solar gains. However a more pragmatic approach may lead towards the installation of a mechanical heat recovery ventilation system. This would build on the existing tight building fabric tackling ventilation through controlling hot and cold air exchanges within the building, in theory dramatically reducing HLC ventilation and the subsequent result of an extremely low energy consumption value. When the concept is placed in a realistic sense, the cost of the MVHR system may not be worth the reduction in energy bill as currently a low bill exists of around £738.05 P.A possibly making it financially unviable.

 


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120

Individual Analysis Conclusion

Through individual analysis of our dwellings, three distinct housing construction typologies emerged. One of which would be redesigned to improve its environmental performance; aiming to reach a PassivHaus standard and an optimum occupant comfort level. The studied typologies are: • Cavity Wall Detached Houses- located in Newport, Wales (Jonathon H) & Watford, England (Jonathan B) • Cavity Wall Semi-Detached House- located in Nottingham, England • Timber Frame Detached House- Located in Beaconsfield, England Fabric Comparison

 

Wall U-Value

Roof U-Value 1.2

0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0

1 0.8 0.6 0.4 0.2 0 Jonathan B

Lidan

Cameron

Jonathon H PassivHaus

         

Jonathan B

Lidan

Cameron

Jonathon H PassivHaus

The highest wall U- values are in the two detached cavity wall structures. Jonathon H’s composite wall structure has the original insulation installed in 1999. Jonathan B’s insulation was installed into a previously empty cavity in 1976. The age of Jonathan B’s insulation suggests a large scope to reduce the Wall U-Value towards PassivHaus standard by replacing this with a better performing material.

 

From the graph it is visible that Jonathan B’s roof structure has considerably higher U-Values in some of the roof elements than the other dwellings analysed. The original flat roof structure takes up 10% of the total roof area and currently has no insulation. This weak spot in the envelope could be easily improved, creating a better performing roof system. When analysing bridging at structural joints and through building fabric, numerous easily avoidable geometric bridges occur. Cameron’s dwelling comes relatively close to PassivHaus values. Timber frame constructions are common in PassivHaus builds, with cavity wall systems being less common. This wall design gives Cameron’s house potential to easily reach PassivHaus standard without too much renovation. Issues and Strategies | Detached Cavity Wall (Jonathan B) Moisture in the bathrooms often escapes into the rest of the house after shower use, displaying an inadequate extraction system that could be solved by a more efficient MV system. Likewise a more efficient extraction system in the kitchen would be beneficial as odours escape into the rest of the house lingering in the downstairs reception rooms. These two issues have knock on effects on occupant comfort and could be easily resolved. By using a heat exchanger it is likely that warmth will be equally spread around the house also. The current heating system struggles to supply to some of the furthest radiators, with those in the far west extension of the house much more inefficient than those in the main spaces. Locating the exchanger centrally, rather than the current boiler location (in the garage on the far east side), a more efficient supply will be sustained. |Detached Timber Frame (Cameron) Ventilation problems exist on the south façade rooms on the ground floor level. Air from the bathroom seeps into the bedroom leading to condensation builds up on windows and a high constantly varying humidity within the space. These windows open to an extremely sheltered area not sufficient to solve the problem. The location of these windows was fixed due to planning regulations; therefore the only plausible ventilation strategy that exists is Mechanical. The well-ventilated first floor spaces are nicer living areas than the ground floor as a result of this issue. |Detached Cavity Wall (Jonathon H) There is no obvious (if any) cross or stack ventilation options that occur within the building. To help incorporate greater ventilation throughout some of the rooms in the house, there are some basic renovation details that could be addressed. For example, if the study was switched with the dining room on the ground floor and the wall was knocked through to the kitchen,

 


cross ventilation would then occur in these rooms. Creating a kitchen-diner, would also be a much better use of the space and 121 allow more room in the study (which is what is needed!) |Semi-Detached Cavity Wall (Lidan) Neighbours’  houses  and  bushes  both  from  the  front  and  the  rear  surround  the  house,  as  a  consequence,  the  ventilation  is   quite  inefficient  through  these  objects.  Within  the  house,  the  air  change  rate  is  limited  because  no  short  cross  or  stack   ventilation  happens.  Therefore,  as  the  wind  mostly  blows  from  southwest,  the  bedrooms  facing  north  are  not  good   ventilated  which  occurs  bad  air  quality.   Gains

Solar Gains (W)

Internal Gains (W)

12000

2000 1800 1600 1400 1200 1000 800 600 400 200 0

10000 8000 6000 4000 2000 0 Jonathan B

Lidan

Cameron

Jonathon H

         

Jonathan B

Lidan

Cameron

Jonathon H

PassivHaus suggests optimising south facing aspects as a form of natural heating. Jonathan B’s front façade is orientated south. As we will not be re-orientating the building or changing any form, this presents the ideal starting point for a PassivHaus redesign. The proportion of the total roof area facing south is around 40%, giving this house the opportunity to attached photovoltaic cells and produce its own energy. Internal gains give somewhat of a skewed value for reaching PassivHaus carbon emission guidelines. There is a fine balance to achieve between providing new eco technology to reduce electricity usage and utilising waste heat from existing appliances to your design advantage. For example the replacement of high-energy bulbs with energy saving ones provides a simple cost effective solution for reducing carbon emissions, compared to the relative cost of replacing a tumble drier. Due to the similar amount of occupants within each dwelling, their impact on gains is negligible.  

 

Chosen Re-design From this evaluation we have chosen to redesign Jonathan B’s detached house. As well as being one of the worse thermal performing houses within the report, there are a number of opportunities linked with the design and location as outlined above. Our methodological approach remains the same, relating to PassivHaus as a benchmark for unsurpassed environmental performance. A full redesign will be implemented pushing towards PassivHaus standards without altering the aesthetic character or layout of the dwelling. Being located in a small close of 15 Georgian style dwellings, this approach would be necessary to ensure approval of the project on a public and legal level.      

 


Layout & User Comfort

122  

Based on the analysis from the previous individual project we found there was a design opportunity to increase the occupant comfort in the study room by rearranging it with the TV room. The south facing aspect of the study is inappropriate for its use, with issues arising from glare throughout the day. By swapping this with the second lounge, a more suited environment is achievable. Although the glare will also affect the use of the TV, it is used less often and the removal of glare within the study workspaces is of greater importance. The new study location would receive little direct light, and rarely overheat.

PassivHaus When considering PassivHaus as a solution, it is essential that we keep to the guidelines regarding construction and post build usage. It requires us to construct an airtight envelope with extremely low U-values and an integrated mechanical ventilation system. PassivHaus design specifies that u-values for the wall construction should be no more than 0.15W/m²K. In order to reach this value, we will have to make a significant alteration to the original thickness of the insulation within the wall. All the existing windows of the house will also need to be replaced in order to comply with the maximum u-value of 0.80W/m2 K. Due to the airtight envelope, a means of mechanical ventilation with a heat recovery system will need to be incorporated into the design to allow a steady rate of air flow, taking stale air out of the building and bringing fresh air in. We will therefore also have to consider the desired air change rate to prevent excessive heat loss. Construction detailing at junctions and corners must be thought about carefully to try and minimise any geometric bridging, as this will now have a greater effect on the outcome of our total fabric heat loss. PassivHaus guidelines also specify that the overall energy use within the building, for both heating and cooling can be no greater than15kWh/m²a and that the total primary energy can be no more than 120 kWh/m² per year.

House Plan

 


123  

  Cavity Wall Design

In order to obtain lower cavity wall U-values, more resistive and thicker cavity wall insulation must be used. Cavity walls are not common in PassivHaus buildings, with other methods being recommended to create the best thermal results. Research into insulation manufacturers showed a cavity thickness of 300mm was best suited to obtain PassivHaus results with the cavity construction.

Cavity wall - Upper value

(Values from CIBSE Guide A & Conductivity values for earth wool from http://www.knaufinsulation.co.uk. Calculations using equation 1) Layer Material Proportion of surface area (%) Thickness (mm) Conductivity λ (W/mK) Resistance (m 2 K/W) 1 External surface 0.04 2A Brickwork outer leaf 0.9 100 0.77 0.12987013 2B Mortar 0.1 100 0.88 0.113636364 3A Earthwool DriTherm Cavity Slab 32 0.999 300 0.032 9.375 3B Stainless steel tie 0.001 5 17 0.000294118 4A AAC Block work 0.93 100 0.11 0.909090909 4B Mortar 0.07 100 0.88 0.113636364 5 Plaster 1 10 0.22 0.045454545 6 Internal Surface 0.12 (Calculations using equation 2) Path/Layer fractional area 1 2 3 4 5 6 7 8

2 0.9 0.9 0.9 0.9 0.1 0.1 0.1 0.1

3 0.999 0.001 0.999 0.001 0.999 0.001 0.999 0.001

4 0.93 0.93 0.07 0.07 0.93 0.93 0.07 0.07

5 1 1 1 1 1 1 1 1

F total 0.836163 0.000837 0.062937 0.000063 0.092907 0.000093 0.006993 0.000007

Resistance (m 2 K/W) 10.61941558 1.244709702 9.823961039 0.449255157 10.60318182 1.228475936 9.807727273 0.43302139

F/R 0.078739079 0.000672446 0.006406479 0.000140232 0.008762181 7.57036E-05 0.000713009 1.61655E-05

Total R Upper (1/Total)

0.095525295 10.4684314

Cavity wall - Lower value (Calculations using equation 3) Layer Fractional area, F 2A 0.9 2B 0.1 3A 0.999 3B 0.001 4A 0.93 4B 0.07

Thermal resistance per path (m 2 K/W) 0.12987013 0.113636364 9.375 0.000294118 0.909090909 0.113636364

F/R 6.93 0.88 0.10656 3.4 1.023 0.616

Path total 7.81

1/Total 0.128040973

3.50656

0.285179777

1.639

0.610128127

 


Layer 1 2 3 4 6 7

Material External surface Brickwork outer leaf & mortar Insulation & ties AAC Block work & mortar Plaster Internal Surface R lower

Thermal Resistance (m 2 K/W) 0.04 0.128040973 0.285179777 0.610128127 0.045454545 0.12 1.228803423

124  

Cavity wall - Total (Calculations using equation 4) R upper (m 2 K/W) R lower (m 2 K/W) R Total (m2 K/W) Wall U-Value W/m2 K

10.4684314 1.228803423 5.848617411 0.17098058

The value of 0.17 is a massive improvement on the previous cavity wall value of 0.44, but falls just short of the 0.15 values for PassivHaus standard. This shows potentially the reasons for not utilising cavity construction in new build methods potentially due to the conductivity of mortar and brickwork.

Cavity Wall Design – Continued It was found that a 39.5mm layer of internal plasterboard insulation could lower the u value to a value to within PassivHaus standards.

Cavity wall - Upper value (Values from CIBSE Guide A & Conductivity values for earth wool from http://www.knaufinsulation.co.uk. Calculations using equation 1) Layer Material Proportion of surface area (%) Thickness (mm) Conductivity λ (W/mK) Resistance (m 2 K/W) 1 External surface 0.04 2A Brickwork outer leaf 0.9 100 0.77 0.12987013 2B Mortar 0.1 100 0.88 0.113636364 3A Earthwool DriTherm Cavity Slab 32 0.999 300 0.032 9.375 3B Stainless steel tie 0.001 5 17 0.000294118 4A AAC Block work 0.93 100 0.11 0.909090909 4B Mortar 0.07 100 0.88 0.113636364 5 Gyproc wallboard 1 9.5 0.19 0.05 6 Super phenolic foam 30 0.02 1.5 7 Internal Surface 0.12

 


(Calculations using equation 2) Path/Layer fractional area 1 2 3 4 5 6 7 8

2 0.9 0.9 0.9 0.9 0.1 0.1 0.1 0.1

3 0.999 0.001 0.999 0.001 0.999 0.001 0.999 0.001

4 0.93 0.93 0.07 0.07 0.93 0.93 0.07 0.07

5 1 1 1 1 1 1 1 1

6 1 1 1 1 1 1 1 1

F total 0.836163 0.000837 0.062937 0.000063 0.092907 0.000093 0.006993 0.000007

Resistance (m 2 K/W) 12.12396104 2.749255157 11.32850649 1.953800611 12.10772727 2.73302139 11.31227273 1.937566845

F/R 0.068967807 0.000304446 0.005555631 3.22448E-05 0.007673364 3.40283E-05 0.000618178 3.61278E-06

Total R upper - 1/Total

0.083189312 12.02077502

125  

Cavity wall - Lower value (Calculations using equation 3) Layer Fractional area, F 2A 0.9 2B 0.1 3A 0.999 3B 0.001 4A 0.93 4B 0.07 Layer 1 2 3 4 5 6 7

Thermal resistance per path (m 2 K/W) 0.12987013 0.113636364 9.375 0.000294118 0.909090909 0.113636364

Material External surface Brickwork outer leaf & mortar Insulation & ties AAC Block work & mortar Gyproc wallboard Super phenolic foam Internal Surface R lower

F/R 6.93 0.88 0.10656 3.4 1.023 0.616

Path total 7.81

1/Total 0.128040973

3.50656

0.285179777

1.639

0.610128127

Thermal Resistance (m 2 K/W) 0.04 0.128040973 0.285179777 0.610128127 0.05 1.5 0.12 2.733348877

Cavity wall - Total

(Calculations using equation 4) R upper (m 2 K/W) R lower (m 2 K/W) R Total (m2 K/W) Wall U-Value W/m2 K

12.02077502 2.733348877 7.377061949 0.135555321

When applying the extra internal insulation the total u-value falls within PassivHaus requirements. However, we have made a decision against the installation of this plasterboard due to the loss of volumetric space and the cost implications of applying the additional layer.

Roof/Ceiling Design Main roof

 


Main roof - Upper value (Values from CIBSE Guide. Calculations using equation 1) Layer Material Proportion of surface area 1a Timber joists 0.1 1b Insulation 0.9 2 Insulation above joists 1 3 Plasterboard 1 4 Plaster 1 5 Internal surface (Calculations using equation 2) Path F Total 1 1 0.9 1 0.9 2 1 1 0.1 0.1 3

Thickness (mm) 150 150 200 10 10 -

Resistance total (m 2 K/W) 8.1625 5.907255245

F/R 0.110260337 0.016928336

Total R upper (1/Tota)l

0.127188673 7.862335374

Conductivity λ (W/mK) 0.13 0.044 0.044 0.16 0.22 -

Resistance (m 2 K/W) 1.153846154 3.409090909 4.545454545 0.0625 0.045454545 0.1

126  

Main roof - Lower value (Calculations using equation 3) Layer Fractional area, F 1a 0.1 1b 0.9 Layer 1 2 3 4 5

Thermal resistance per path (m 2 K/W) 1.153846154 3.409090909

Material Timber/Insulation Insulation above joists Plasterboard Plaster Internal surface R Lower

F/R 0.0867 0.264

Path total 0.3507

1/Total 2.851711027

Thermal Resistance 2.851711027 4.545454545 0.0625 0.045454545 0.1 7.605120118

Main roof - Total R upper (m 2 K/W) R lower (m 2 K/W) R Total (m2 K/W)

7.862335374 7.605120118 7.733727746

(CIBSE Guide A - table 3.5 used for surface resistance. Table 3.9 for pitched roof resistance. Calculations using equation4) Layer Material Thermal Resistance 1 External surface 0.4 2 Pitched roof 0.2 3 Bridged ceiling 7.733727746 R TOTAL (m2 K/W) U-Value (W/m2 K)

8.333727746 0.119994321

Flat roof

 


Flat roof - Upper value (Values from CIBSE Guide A. Calculations using equation 1) Layer Material Proportion of surface area 1 External surface 2 Bitumen 1 3 Bitumen felt 1 4 Insulation 1 5 Plywood deck 1 5A Air cavity (unvented) 0.8 5B Timber joists 0.2 6 Plasterboard 1 7 Internal Surface (Calculations using equation 2) Path 2 3 4 5 6 1 1 1 1 1 0.8 2 1 1 1 1 0.2

Thickness (mm) 5 15 150 19 150 12.5 -

Conductivity λ (W/mK) 0.5 0.19 0.025 0.12 0.13 0.16 -

F Total

Resistance total (m 2 K/W)

F/R

0.8 0.2

7.005405702 7.979251856

0.114197526 0.025065007

Total R upper (1/Total)

0.139262533 7.18068228

Resistance (m 2 K/W) 0.4 0.01 0.078947368 6 0.158333333 0.18 1.153846154 0.078125 0.1

127  

Flat roof - Lower value (Calculations using equation 3) Layer Fractional area, F

Thermal resistance per path (m 2 K/W)

F/R

Path total

1/Total

0.18 1.153846154

4.444444444 0.173333333

4.617777778

0.216554379

4a 4b

0.8 0.2

Layer

Material

Thermal Resistance (m 2 K/W)

1 2 3 4 5 6 7 9

External surface Bitumen Felt Insulation Plywood deck Unvented gap & timber joists Plasterboard Internal Surface R lower

0.4 0.01 0.078947368 6 0.158333333 0.216554379 0.078125 0.1 7.041960081

Roof - Total R upper (m 2 K/W) R lower (m 2 K/W) R TOTAL (m 2 K/W) F/roof U value

7.18068228 7.041960081 7.111321181 0.140620846

Roof values have significantly improved, especially with the inclusion of insulation in the flat roof construction; previously a weak spot in the thermal envelope. Quilt insulation thickness has been increased in the loft to 350mm from the original 100mm.

Floor Design (Calculations using equation 4 & CIBSE table values) Perimeter (m) Area (m2) P/A (m/m2) Thermal resistance 48.915 99.8855 0.489710719 2.5 U Value 0.24

Due to the large perimeter to area ratio of the ground floor, the u value is still relatively high for PassivHaus. Because the internal layout of the house is to remain the same, we were unable to calculate a smaller value.

Openings Design U Value Triple glazed openings

0.776

To lower the glazing U – Value to a desired value of 0.8 we have replaced the existing with low – E coated triple glazed units with 16mm argon filled cavities & thermix insulated warm edge spacers. This glazing u value falls below PassivHaus requirements, providing good thermal performance in comparison to the original double-glazing.

 


128  

  Geometric Bridging

Geometric bridging in PassivHaus plays a big part in thermal losses, with values accounting for a higher proportion of envelope losses as HLC values for fabric decrease. Good construction detailing can help reduce geometric bridging as shown in the diagrams below. However, SAP2009 only supplies generic values for thermal transmittance so the table remains the same. FRONT 1 Ground floor Flat roof Corners WEST 1 Ground floor Flat roof Inverted corner FRONT 2 Ground floor Intermediate floor Eaves Corners WEST 2 Ground floor Intermediate Gable Corners FRONT 3 Ground floor Intermediate Eaves Corners WEST 3 Ground floor Intermediate Gable Corners FRONT 4 Ground floor Intermediate Eaves Corners WEST 3 Ground floor Intermediate Gable Corners REAR 1 Ground floor Intermediate Eaves Corners REAR 2 EXTENSION Ground floor Flat roof Corners EAST 1 EXTENTION Ground floor Flat roof Corners FRONT 5 EXTENTION Ground floor Flat roof Corners EAST 2 Ground floor Intermediate Gable EAST 3 Intermediate Gable TOTAL (W/K)

Linear thermal transmittance ψ (W/mK)

Length of bridge L (mm)

(Lx ψ) W/K

0.16 0.04 0.09

2700 2700 4800

0.432 0.108 0.432

0.16 0.04 -0.09

1775 1775 2400

0.284 0.071 -0.216

0.16 0.07 0.06 0.09

5860 8560 8560 7900

0.9376 0.5992 0.5136 0.711

0.16 0.07 0.24 -0.09

1600 1600 1600 5150

0.256 0.112 0.384 -0.4635

0.16 0.07 0.06 0.09

2975 2975 2975 5150

0.476 0.20825 0.1785 0.4635

0.16 0.07 0.24 -0.09

1100 1100 1100 5150

0.176 0.077 0.264 -0.4635

0.16 0.07 0.06 0.09

500 500 500 5150

0.08 0.035 0.03 0.4635

0.16 0.07 0.24 -0.09

4950 4950 4950 5150

0.792 0.3465 1.188 -0.4635

0.16 0.07 0.06 0.09

12025 12025 12025 5150

1.924 0.84175 0.7215 0.4635

0.16 0.04 0.09

2875 2875 2650

0.46 0.115 0.2385

0.16 0.04 0.09

4000 4000 2650

0.64 0.16 0.2385

0.16 0.04 -0.09

2875 2875 2650

0.46 0.115 -0.2385

0.16 0.07 0.24

5425 3650 3650

0.868 0.2555 0.876

0.07 0.24

4000 4000

0.28 0.96 17.3909

 


129  

 

Geometric bridging illustration – Wall to roof

A continuous route of insulation around the house envelope helps to minimise heat loss at geometric bridges. Bridging technologies such as thermoblocks have been inserted into block work to prevent thermal transmittance through the materials at junctions. These help to continue this consistent route of insulation.

150mm of insultion at rafter level

Two large layers of insulation at ceiling level stored within the joists.

Roof and wall insulation extended to connect a fluid path preventing the illustrated geometric bridge.

Continuous ribbon of adhesive behind plasterboard

Geometric bridging illustration – Wall to ground

.

 


130  

  Building Fabric Analysis (Calculations using equation 5. HLC is based on corrected surface areas of exterior walls following the cavity redesign) U-Value (W/m 2 K) AREA (m 2 ) HLC (UxA (W/K) Heat loss geometric bridging HLC TOTAL (W/K) Ground 0.24 99.8855 23.97252 23.97252 Roof 0.119994321 84.2175 10.10562171 10.10562171 Flat roof 0.140620846 14.8625 2.089977322 2.089977322 South facing walls 0.135555321 60.0135 8.135149253 5.66815 13.80329925 East facing walls 0.135555321 47.15125 6.391602826 3.2395 9.631102826 West facing walls 0.135555321 53.68875 7.277795737 2.344 9.621795737 North facing walls 0.135555321 55.8375 7.569070233 3.95075 11.51982023 Windows 0.776 36.28 28.15328 28.15328 Doors 0.776 4.2 3.2592 3.2592 Total

112.1566171

250

200

150

Area (m2) HLC (W/K)

100

50

0 Original Floor

Floor

Original Roof

Roof

Original Walls

Walls

Original Windows

Windows

Original Doors

Doors

(Calculations using equations 12, 14 and 15) HLC Total

112.1566171

Ti - To

9

Heat Loss (W)

1009.409554

Energy (J)

31832739685.36

Energy (kWh)

8842.42769

Emissions

0.19 2

Carbon emissions (kg co )

1680.061261

Air tightness PassivHaus requirements necessitate an airtight envelope with an air change rate of ≥ 0.6 air changes per hour at 50pa. Doors and windows will have draft proof seals and good construction techniques to minimise unsealed leakages through the envelope.

 


Ventilation

131  

This airtight envelope will be ventilated by a mechanical ventilation heat recovery system (MVHR). The system will be installed with ducts across the house with minimum turns and manoeuvres to maximise air flow potential. Supply ducts will be fitted 100mm from ground level in all living and reception spaces within the house providing these areas with fresh air. Extract ducts will be fitted 100mm from the ceiling to kitchen, bathroom and utility areas to remove waste air, preventing the build up of moisture and toxins. These must be located below 400mm from the ceiling height as described in building regulations part F table 5.2C.

 


The chosen air change rate for the dwelling is 0.4 air changes per hour. This is recommended by PassivHaus for domestic settings, creating a healthy balance between air quality and minimal heat loss.

132  

During the winter months the heat recovery system is used to recover heat from the waste exhaust air, heating up the inlet air supply without contaminating it. The Paul MVHR Novus 300 is a manufacture example of a heat recovery system to be installed in the house. This particular model has a heat recovery efficiency of 93% and has been factored into the calculations below. During the summer months the heat recovery element of the system can be bypassed, with exhaust air escaping without heating up the inlet air. This helps regulate a healthy and comfortable temperature without chance of overheating. Due to the large amount of insulation, overheating may occur. If so, window openings can be used to trigger cross and single sided ventilation within the house volumes. Based on the PassivHaus benchmark value for N, we calculated the volume flow rate, Q. This was then used to calculate effective areas for the vent sizes showing the proportion of ventilation supply/extraction in relation to room volume. (Calculations using equations 9 and 17) N Living room Supply 0.4 TV room Supply 0.4 Study Supply 0.4 Kitchen Extract 0.4 Bedroom 1 Supply 0.4 Bedroom 2 Supply 0.4 Bedroom 3 Supply 0.4 Bedroom 4 Supply 0.4 Spare bedroom Supply 0.4 Bathroom1 Extract 0.4 Bathroom 2 Extract 0.4 Hallway upstairs Supply 0.4 Hallway downstairs Supply 0.4 Utility room Extract 0.4

3600 3600 3600 3600 3600 3600 3600 3600 3600 3600 3600 3600 3600 3600 3600

V 58.752 45.144 25.596 57.36 33.966 33.078 30.894 17.496 28.608 12.7656 15.768 21.888 21.888 16.2

Q 0.0065 0.0050 0.0028 0.0064 0.0038 0.0037 0.0034 0.0019 0.0032 0.0014 0.0018 0.0024 0.0024 0.0018

Cd 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61

(TiTo )*2 1 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66

(TiTo)/2 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915

H 8.05 8.05 8.05 5.85 5.4 5.4 5.4 5.4 5.4 3.2 3.2 5.4 8.05 5.85

G 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81

273 273 273 273 273 273 273 273 273 273 273 273 273 273 273

1 0.2852 4.4659 4.4659 3.2454 2.9958 2.9958 2.9958 2.9958 2.9958 1.7753 1.7753 2.9958 4.4659 3.2454

2 0.3258 1.2891 1.2891 1.0989 1.0558 1.0558 1.0558 1.0558 1.0558 0.8128 0.8128 1.0558 1.2891 1.0989

Aw 0.0200 0.0039 0.0022 0.0058 0.0036 0.0035 0.0033 0.0018 0.0030 0.0017 0.0022 0.0023 0.0019 0.0016

Winter ventilation HLC The particularly low HLC values are due to the high efficiency rate (93%) of our chosen heat recovery system, with waste heat being recycled and used by inlet air. (Calculations using equation 10) N V Living room 0.4 58.752 TV room 0.4 45.144 Study 0.4 25.596 Kitchen 0.4 57.36 Bedroom 1 0.4 33.966 Bedroom 2 0.4 33.078 Bedroom 3 0.4 30.894 Bedroom 4 0.4 17.496 Spare bedroom 0.4 28.608 Bathroom1 0.4 12.7656 Bathroom 2 0.4 15.768 Hallway upstairs 0.4 21.888 Hallway downstairs 0.4 21.888 Utility room 0.4 16.2

HLC 7.8336 6.0192 3.4128 7.648 4.5288 4.4104 4.1192 2.3328 3.8144 1.70208 2.1024 2.9184 2.9184 2.16

Efficiency % 93 93 93 93 93 93 93 93 93 93 93 93 93 93

Real HLC 0.548352 0.421344 0.238896 0.53536 0.317016 0.308728 0.288344 0.163296 0.267008 0.1191456 0.147168 0.204288 0.204288 0.1512

Total winter HLC

3.9144336

 


133  

 

Summer ventilation HLC As mentioned previously, during the summer months (June, July August), the heat recovery element can be bypassed and heat is allowed to escape from extract ducts. This explains the higher HLC values below. (Calculations using equation 10) N V Living room 0.4 58.752 TV room 0.4 45.144 Study 0.4 25.596 Kitchen 0.4 57.36 Bedroom 1 0.4 33.966 Bedroom 2 0.4 33.078 Bedroom 3 0.4 30.894 Bedroom 4 0.4 17.496 Spare bedroom 0.4 28.608 Bathroom1 0.4 12.7656 Bathroom 2 0.4 15.768 Hallway upstairs 0.4 21.888 Hallway downstairs 0.4 21.888 Utility room 0.4 16.2

HLC 7.8336 6.0192 3.4128 7.648 4.5288 4.4104 4.1192 2.3328 3.8144 1.70208 2.1024 2.9184 2.9184 2.16

Efficiency % 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Real HLC 7.8336 6.0192 3.4128 7.648 4.5288 4.4104 4.1192 2.3328 3.8144 1.70208 2.1024 2.9184 2.9184 2.16

Total summer HLC

55.92048

Ventilation analysis

(Calculations using equation 12, 14 & 15) Summer HLC Total 55.92048 Ti - To 1.3 Heat loss (W) 72.696624 Energy (J) 577850924.9 Energy (kWh) 160.5141458 Emissions factor 0.19 Carbon emissions (KG CO 2 ) 30.4976877

Winter 3.9144336 10 39.144336 923305282.1 256.4736895 0.19 48.730001

Total 59.8349136 11.3 111.84096 1501156207 416.9878353 0.19 79.2276887

Original ventilation values for winter (Calculations using equation 12, 14 & 15) Winter HLC Total 228.78936 Ti - To 9 Heat loss (W) 2059.10424 Energy (J) 64935911313 Energy (kWh) 18037.75314 Emissions factor 0.19 Carbon emissions (KG CO 2 ) 3427.173097

 


134  

  Solar Gains

Horizontal/vertical solar flux conversion Representative Latitude (o N) 51.5

Solar radiation on the horizontal (W/m2) Jun Jul 214 204

Aug 177

(Calculations using equation 16 & Excel spreadsheet ‘converting horizontal to vertical solar flux) Façade orientation - 180 Façade orientation - 90 Façade orientation - 0 Results SVertical (m), W/m2 Results SVertical (m), W/m2 Results SVertical (m), W/m2 January 47.3233189 January 19.87256466 January 10.72641674 February 77.1832044 February 38.51867736 February 20.35879704 March 94.2460544 March 61.56524736 March 33.30872704 April 105.11436 April 91.409784 April 54.639576 May 108.549926 May 111.2196844 May 75.2159916 June 114.5726896 June 122.9558742 June 91.97853536 July 110.5232934 July 117.784192 July 85.34413644 August 107.4132642 August 104.9219255 August 67.65654372 September 99.990985 September 73.603769 September 41.085141 October 85.2918322 October 46.90850868 October 24.81434852 November 56.0693298 November 24.70675812 November 13.21801668 December 40.8904104 December 16.39290576 December 8.94448464

Opening characteristics (Calculations using values from CIBSE Guide A, Table 6b & 6d) Façade Solar transmittance Living room front S 0.57 Living room rear N 0.57 TV room front S 0.57 TV room rear N 0.57 Study S 0.57 Hallway downstairs S 0.57 Kitchen N 0.57 Kitchen 2 E 0.57 Bedroom 1 S 0.57 Bedroom 2 N 0.57 Bedroom 3 N 0.57 Bedroom 4 S 0.57 Spare bedroom N 0.57 Hallway upstairs S 0.57 Bathroom 1 E 0.57 Bathroom 2 S 0.57

Solar access 0.54 0.77 0.3 0.77 1 1 0.77 0.77 0.54 1 0.77 1 0.54 1 0.77 0.54

Opening area 2.9 5 2.16 2.16 2.9 3.1 6.4 0.6 2.16 2.88 2.88 1.44 2.16 1.44 0.9 1.44

Frame factor 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7

Room solar gain values

(Calculations using spreadsheet ‘Calculating solar gains’. Utility room excluded due to absence of window) Liv S Liv N TV S TV N Study Hall D January 26.6123 14.8296 11.01198487 6.4064 49.2820 52.6808 February 43.4040 28.1467 17.96028468 12.1594 80.3778 85.9211 March 52.9993 46.0505 21.93075527 19.8938 98.1469 104.9157 April 59.1111 75.5411 24.45977521 32.6338 109.4650 117.0144 May 61.0431 103.9887 25.25922042 44.9231 113.0428 120.8389 June 64.4300 127.1635 26.66069824 54.9347 119.3149 127.5435 July 62.1528 117.9913 25.7184167 50.9722 115.0979 123.0356 August 60.4039 93.5375 24.99472286 40.4082 111.8591 119.5735 September 56.2300 56.8016 23.26758224 24.5383 104.1296 111.3110 October 47.9639 34.3067 19.84713642 14.8205 88.8221 94.9477 November 31.5306 18.2744 13.04715362 7.8945 58.3900 62.4169 December 22.9947 12.3661 9.515067651 5.3421 42.5829 45.5196

January February March April May

Bed 1 19.8216 32.3285 39.4754 44.0276 45.4666

Bed 2 11.0933 21.0552 34.4482 56.5087 77.7890

Bed 3 8.5419 16.2125 26.5251 43.5117 59.8975

Bed 4 24.4711 39.9117 48.7350 54.3551 56.1316

Bed 5 4.4928 8.5274 13.9515 22.8860 31.5045

Bath 1 4.9454 9.5856 15.3209 22.7479 27.6777

Hall U 24.4711 39.9117 48.7350 54.3551 56.1316 59.2460 57.1520 55.5438 51.7057 44.1047 28.9937 21.1446

Kitchen 18.9819 36.0278 58.9446 96.6926 133.1056 162.7693 151.0288 119.7281 72.7061 43.9126 23.3912 15.8286

Bath 2 13.2144 21.5523 26.3169 29.3517 30.3111

TOTAL 294.1536 499.4727 666.6034 857.8268 1005.5629

 


June July August September October November December

47.9893 46.2932 44.9905 41.8816 35.7248 23.4849 17.1271

95.1249 88.2636 69.9709 42.4906 25.6632 13.6702 9.2505

73.2462 67.9630 53.8776 32.7177 19.7607 10.5260 7.1229

59.2460 57.1520 55.5438 51.7057 44.1047 28.9937 21.1446

38.5256 35.7468 28.3382 17.2087 10.3936 5.5364 3.7464

30.5983 29.3113 26.1105 18.3168 11.6735 6.1484 4.0795

31.9928 30.8621 29.9937 27.9211 23.8166 15.6566 11.4181

1139.1846 1078.2819 952.2812 745.1434 567.6448 352.0537 251.9023

Total (W) Energy (J) Energy (kWh)

8410.1113 265,221,000,000 73672.57473

135  

Monthly solar gains – Original & new values 1600.0000 1400.0000 1200.0000 1000.0000 800.0000 Solar gain

600.0000

Original Solar gain

400.0000 200.0000 0.0000

As can be seen by the graph above, solar gains have decreased from the original study. This is due to the installation of triple glazed low e coated glass. This makes an impact on the solar transmittance value, decreasing from 0.76 for PVC-U double-glazing to 0.57 for the new glazing construction. This lower value means less solar energy entering the internal volumes through the glazed openings in the envelope.

Internal Gains Lighting gains (Calculations using equation 14) Light type Living room front Incandescent 40W Living room rear Incandescent 40W TV room Incandescent 40W Study Incandescent 40W Hallway downstairs Incandescent 40W Kitchen main GU10 Halogen Kitchen side GU10 Halogen Breakfast room GU10 Halogen Bedroom 1 Incandescent 40W Bedroom 2 GU10 Halogen Bedroom 3 Incandescent 40W Bedroom 4 GU10 Halogen Spare bedroom GU10 Halogen Hallway upstairs Incandescent 40W Bathroom 1 GU10 Halogen Bathroom 2 GU10 Halogen Utility Room GU10 Halogen

No. Fittings 5 5 8 3 3 6 4 4 4 4 4 1 6 3 4 4 4

Power (W) 8 8 8 8 8 11 11 11 8 11 8 11 11 8 11 11 11

Total power (W) 40 40 64 24 24 66 44 44 32 44 32 11 66 24 44 44 44

Time (S) 21600 300 600 1800 1800 10800 18000 1200 7200 18000 0 21600 300 10800 3600 3600 1800 Total energy (J) Q L ighting (W)

Energy (J) 864000 12000 38400 43200 43200 712800 792000 52800 230400 792000 0 237600 19800 259200 158400 158400 79200 4493400 52.00694444

 


Following research into energy efficient bulbs we have found GU10 50w equivalent bulbs running at 11w, and incandescent 40w equivalent running at 8w.

136  

Appliance gains (Calculations using equation 14) Appliance Living room front LCD TV Laptop TV room CRT TV Study Desktop computer LCD TV Kitchen main Oven Microwave Dishwasher Fridge/freezer Breakfast room LCD TV Bedroom 2 LCD TV Desktop computer Stereo Bedroom 4 LCD TV Laptop Stereo Spare bedroom Projector Stereo Bathroom 1 Power shower Bathroom 2 Power shower Utility Room Washing Machine Tumble drier

Power (W) 120 30 150 130 120 1200 1000 1200 500 120 120 130 90 120 30 90 220 90 240 240 500 4000

Time (S) 18000 7200 900 1800 600 3600 600 3600 86400 3600 10800 14400 7200 3600 28800 3600 600 600 1800 1200 1800 0

Energy (J) 2160000 216000 135000 234000 72000 4320000 600000 4320000 43200000 432000 1296000 1872000 648000 432000 864000 324000 132000 54000 432000 288000 900000 0

Total energy (J) QAppliance (W)

62931000 728.3680556

Metabolic gains (Calculations using equation 14) Gain (W) Time (S) Male 115 18000 140 7200 Male 115 14400 140 7200 Male 115 14400 265 2700 Female 115 9000 140 1800 Total energy (J) Q metabolic (W)

Metabolic energy (J) 2070000 1008000 1656000 1008000 1656000 715500 1035000 252000 9400500 108.8020833

Internal gains analysis Q Lighting (W)

108.8020833

Q Appliance (W)

728.3680556

Q me tabolic (W)

52.00694444

Q Total (W)

889.1770833

 


137  

  Balance Point

Total heat gains per month Month January February March April May June July August September October November December

QSolar 294.1536 499.4727 666.6034 857.8268 1005.5629 1139.1846 1078.2819 952.2812 745.1434 567.6448 352.0537 251.9023

QInternal 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833

Qtotal heat gain 1183.3307 1388.6498 1555.7805 1747.0039 1894.7400 2028.3617 1967.4590 1841.4582 1634.3205 1456.8219 1241.2308 1141.0794

Qtotal Heat loss (September – May) (Calculations using equation 12) To Ti Delta T HLC -1 21 22 116.0710507 -0.5 21 21.5 116.0710507 0 21 21 116.0710507 0.5 21 20.5 116.0710507 1 21 20 116.0710507 1.5 21 19.5 116.0710507 2 21 19 116.0710507 2.5 21 18.5 116.0710507 3 21 18 116.0710507 3.5 21 17.5 116.0710507 4 21 17 116.0710507 4.5 21 16.5 116.0710507 5 21 16 116.0710507 5.5 21 15.5 116.0710507 6 21 15 116.0710507 6.5 21 14.5 116.0710507 7 21 14 116.0710507 7.5 21 13.5 116.0710507 8 21 13 116.0710507 8.5 21 12.5 116.0710507 9 21 12 116.0710507 9.5 21 11.5 116.0710507 10 21 11 116.0710507 10.5 21 10.5 116.0710507 11 21 10 116.0710507 11.5 21 9.5 116.0710507 12 21 9 116.0710507 12.5 21 8.5 116.0710507 13 21 8 116.0710507 13.5 21 7.5 116.0710507 14 21 7 116.0710507 14.5 21 6.5 116.0710507 15 21 6 116.0710507 15.5 21 5.5 116.0710507 16 21 5 116.0710507 16.5 21 4.5 116.0710507 17 21 4 116.0710507 17.5 21 3.5 116.0710507 18 21 3 116.0710507 18.5 21 2.5 116.0710507 19 21 2 116.0710507 19.5 21 1.5 116.0710507 20 21 1 116.0710507 20.5 21 0.5 116.0710507 21 21 0 116.0710507

Qtotal heat loss 2553.563115 2495.52759 2437.492065 2379.456539 2321.421014 2263.385489 2205.349963 2147.314438 2089.278913 2031.243387 1973.207862 1915.172337 1857.136811 1799.101286 1741.065761 1683.030235 1624.99471 1566.959184 1508.923659 1450.888134 1392.852608 1334.817083 1276.781558 1218.746032 1160.710507 1102.674982 1044.639456 986.603931 928.5684056 870.5328803 812.4973549 754.4618296 696.4263042 638.3907789 580.3552535 522.3197282 464.2842028 406.2486775 348.2131521 290.1776268 232.1421014 174.1065761 116.0710507 58.03552535 0

 


138  

 

January

February

March

April

May

June

July

August

September

October

November

December

-1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21

Qtotal heat loss

To

Balance points - (September – May)

2553.56 2495.53 2437.49 2379.46 2321.42 2263.39 2205.35 2147.31 2089.28 2031.24 1973.21 1915.17 1857.14 1799.10 1741.07 1683.03 1624.99 1566.96 1508.92 1450.89 1392.85 1334.82 1276.78 1218.75 1160.71 1102.67 1044.64 986.60 928.57 870.53 812.50 754.46 696.43 638.39 580.36 522.32 464.28 406.25 348.21 290.18 232.14 174.11 116.07 58.04 0.00

1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33

1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65

1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78

1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00

1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74

2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36

1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46

1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46

1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32

1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82

1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23

1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08

10.5 22.6202 58.0355 0.3898 4.0925 11 35.4153 58.0355 0.6102 6.7126

9 53.8327 58.0355 0.9276 8.3482 9.5 4.2028 58.0355 0.0724 0.6880

7.5 46.8568 58.0355 0.8074 6.0554 8 11.1787 58.0355 0.1926 1.5409

5.5 5.9381 58.0355 0.1023 0.5628 6 52.0974 58.0355 0.8977 5.3861

4.5 37.6032 58.0355 0.6479 2.9157 5 20.4323 58.0355 0.3521 1.7603

3.5 55.1538 58.0355 0.9503 3.3262 4 2.8817 58.0355 0.0497 0.1986

4 52.2867 58.0355 0.9009 3.6038 4.5 5.7489 58.0355 0.0991 0.4458

5 42.3569 58.0355 0.7298 3.6492 5.5 15.6786 58.0355 0.2702 1.4859

6.5 9.3258 58.0355 0.1607 1.0445 7 48.7097 58.0355 0.8393 5.8752

8 5.9338 58.0355 0.1022 0.8179 8.5 52.1018 58.0355 0.8978 7.6309

10 22.4848 58.0355 0.3874 3.8743 10.5 35.5508 58.0355 0.6126 6.4320

11 38.4044 58.0355 0.6617 7.2791 11.5 19.6311 58.0355 0.3383 3.8900

10.8051

9.0362

7.5963

5.9488

4.6760

3.5248

4.0495

5.1351

6.9197

8.4489

10.3063

11.1691

Lower

Upper

Balance Point

 


139  

 

Balance Points Graph – September – May

 

3000.00

2500.00

2000.00

Qtotal heat loss January February March April

1500.00

May September October November December

1000.00

500.00

0.00 -1

4

9

14

19

24

 


Qtotal Heat loss (June – August)

Balance points (June - August)

(Calculations using equation 12) To Ti Delta T HLC -1 21 22 168.0770971 -0.5 21 21.5 168.0770971 0 21 21 168.0770971 0.5 21 20.5 168.0770971 1 21 20 168.0770971 1.5 21 19.5 168.0770971 2 21 19 168.0770971 2.5 21 18.5 168.0770971 3 21 18 168.0770971 3.5 21 17.5 168.0770971 4 21 17 168.0770971 4.5 21 16.5 168.0770971 5 21 16 168.0770971 5.5 21 15.5 168.0770971 6 21 15 168.0770971 6.5 21 14.5 168.0770971 7 21 14 168.0770971 7.5 21 13.5 168.0770971 8 21 13 168.0770971 8.5 21 12.5 168.0770971 9 21 12 168.0770971 9.5 21 11.5 168.0770971 10 21 11 168.0770971 10.5 21 10.5 168.0770971 11 21 10 168.0770971 11.5 21 9.5 168.0770971 12 21 9 168.0770971 12.5 21 8.5 168.0770971 13 21 8 168.0770971 13.5 21 7.5 168.0770971 14 21 7 168.0770971 14.5 21 6.5 168.0770971 15 21 6 168.0770971 15.5 21 5.5 168.0770971 16 21 5 168.0770971 16.5 21 4.5 168.0770971 17 21 4 168.0770971 17.5 21 3.5 168.0770971 18 21 3 168.0770971 18.5 21 2.5 168.0770971 19 21 2 168.0770971 19.5 21 1.5 168.0770971 20 21 1 168.0770971 20.5 21 0.5 168.0770971 21 21 0 168.0770971

To -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21

Qtotal heat loss 3697.696136 3613.657588 3529.619039 3445.580491 3361.541942 3277.503393 3193.464845 3109.426296 3025.387748 2941.349199 2857.310651 2773.272102 2689.233554 2605.195005 2521.156457 2437.117908 2353.079359 2269.040811 2185.002262 2100.963714 2016.925165 1932.886617 1848.848068 1764.80952 1680.770971 1596.732422 1512.693874 1428.655325 1344.616777 1260.578228 1176.53968 1092.501131 1008.462583 924.4240341 840.3854855 756.346937 672.3083884 588.2698399 504.2312913 420.1927428 336.1541942 252.1156457 168.0770971 84.03854855 0

June 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617

July 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459

August 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582

Lower

8.5 11.4365348 84.03854855 0.136086772 1.156737562

9 34.57238335 84.03854855 0.411387202 3.702484818

10 76.64868045 84.03854855 0.912065734 9.120657338

Upper

9 72.60201375 84.03854855 0.863913228 7.775219052

9.5 49.4661652 84.03854855 0.588612798 5.591821581

10.5 7.3898681 84.03854855 0.087934266 0.923309795

9.294306399

10.04396713

Balance Point

Qtotal heat loss 3697.696136 3613.657588 3529.619039 3445.580491 3361.541942 3277.503393 3193.464845 3109.426296 3025.387748 2941.349199 2857.310651 2773.272102 2689.233554 2605.195005 2521.156457 2437.117908 2353.079359 2269.040811 2185.002262 2100.963714 2016.925165 1932.886617 1848.848068 1764.80952 1680.770971 1596.732422 1512.693874 1428.655325 1344.616777 1260.578228 1176.53968 1092.501131 1008.462583 924.4240341 840.3854855 756.346937 672.3083884 588.2698399 504.2312913 420.1927428 336.1541942 252.1156457 168.0770971 84.03854855 0

8.931956614

140  

 


141  

 

Balance Points Graph (June – August) 4000

3500

3000

2500

Qtotal heat loss 2000

June July August

1500

1000

500

0 -1

4

9

14

19

24

29

34

39

44

49

 


139  

 

Balance Points Graph – September – May

 

3000.00

2500.00

2000.00

Qtotal heat loss January February March April

1500.00

May September October November December

1000.00

500.00

0.00 -1

4

9

14

19

24

 


143  

  Degree-days & Carbon Emissions Description: Source: Station:

Celsius-based heating degree days for base temperatures at and around 17.5C Www.degreedays.net (using temperature data from www.wunderground.com) London / Heathrow Airport (0.46W, 51.48N) EGLL

Month starting 01/01/2009 01/02/2009 01/03/2009 01/04/2009 01/05/2009 01/06/2009 01/07/2009 01/08/2009 01/09/2009 01/10/2009 01/11/2009 01/12/2009

4.5 60 39 9 0 0 0 0 0 0 0 1 48

5 68 46 12 1 0 0 0 0 0 0 1 56

5.5 78 53 16 1 0 0 0 0 0 0 2 66

6 88 60 19 2 0 0 0 0 0 1 3 76

6.5 100 68 24 3 0 0 0 0 0 1 5 88

7 111 76 28 4 0 0 0 0 0 2 7 99

7.5 124 86 35 6 1 0 0 0 0 3 10 111

8 138 95 41 8 1 0 0 0 0 4 14 123

8.5 152 106 50 11 2 0 0 0 0 6 18 136

9 166 116 58 14 2 0 0 0 0 7 23 149

9.5 181 128 68 18 4 0 0 0 0 9 30 163

10 196 140 78 23 6 1 0 0 0 11 37 177

10.5 212 154 90 30 8 1 0 0 1 15 46 191

11 227 166 101 36 11 2 0 0 2 18 54 206

01/01/2010 01/02/2010 01/03/2010 01/04/2010 01/05/2010 01/06/2010 01/07/2010 01/08/2010 01/09/2010 01/10/2010 01/11/2010 01/12/2010

85 38 19 1 1 0 0 0 0 4 35 108

97 46 23 2 2 0 0 0 0 5 40 120

110 56 29 4 3 0 0 0 0 7 46 133

123 67 35 5 4 0 0 0 0 8 52 146

137 78 42 8 5 0 0 0 0 10 59 160

151 89 49 11 7 0 0 0 0 12 67 174

166 101 57 16 9 0 0 0 1 15 76 189

181 114 65 20 11 0 0 0 1 17 86 204

196 127 75 25 15 0 0 0 2 20 96 220

211 140 84 31 18 0 0 0 3 23 107 235

227 154 96 37 23 0 0 0 4 26 118 250

242 168 106 44 28 1 0 0 5 30 129 266

258 182 118 52 34 1 0 0 7 35 141 281

273 196 130 61 41 2 0 1 9 41 153 297

01/01/2011 01/02/2011 01/03/2011 01/04/2011 01/05/2011 01/06/2011 01/07/2011 01/08/2011 01/09/2011 01/10/2011 01/11/2011 01/12/2011

37 6 17 0 0 0 0 0 0 0 2 13

44 8 20 0 0 0 0 0 0 1 2 17

53 13 25 0 0 0 0 0 0 1 4 22

62 17 30 0 0 0 0 0 0 2 5 26

73 23 36 1 1 0 0 0 0 3 6 33

83 29 42 2 1 0 0 0 0 4 8 40

95 36 50 3 2 0 0 0 0 5 10 49

108 43 58 4 2 0 0 0 0 6 13 58

120 52 67 5 4 0 0 0 0 8 17 68

133 61 76 7 5 1 0 0 0 10 21 78

146 71 86 10 7 2 0 0 1 13 26 90

159 82 97 13 9 2 0 0 2 15 31 101

173 94 109 17 12 4 0 0 2 19 39 113

187 106 121 22 15 5 0 0 3 22 46 126

January February March April May June July August September October November December

DD -2009 227 116 35 2 0

DD - 2010 273 140 57 5 1

DD - 2011 187 61 50 0 0

Mean Average 229 106 47 2 0

-

-

-

-

0 6 46 206

0 20 141 297

0 8 39 126

0 11 75 210

Balance point 10.8051 9.0362 7.5963 5.9488 4.676

HLC 116.0710507 116.0710507 116.0710507 116.0710507 116.0710507

kWh 637.9264946 294.3561846 131.8567136 6.499978839 0.928568406

6.9197 8.4489 10.3063 11.1691

116.0710507 116.0710507 116.0710507 116.0710507

0 31.57132579 209.8564597 584.0695271

Total

1897.065253

 


Total Energy 1897.065253

Emissions factor 0.19

Predicted cost (3.15p per kWh) Property Area (m 2) Kwh/M 2

£59.75755546 183.61 10.33203667

Boiler efficiency 0.902

144  

Carbon emissions (Kg CO2) 399.6035455

Energy consumption comparison - kWh/M2

Actual

10.33203667

PassivHaus

15 Previous New build PassivHaus

New build

Actual

55

Previous

165.6

0

20

40

60

80

100

120

140

160

180

Conclusion Shown above we can see the successful outcomes of our redesign of the dwelling. The actual kWh/m2 value sits at just over 10, with PassivHaus standards being stated at 15 and under. Compared to the previous value of 165.6, this is a vast improvement. Although not specifically designed as a PassivHaus in its form or orientation, the house does live up to many of the regulation values, working “passively” with it’s surrounding environment and occupants. Occupants play a key role in the post construction success of PassivHaus. An environmentally unaware occupant will produce significantly more carbon emissions through appliance gains, over ventilation and poor monitoring of solar gains (blinds). The concept behind “passive” house is to have a house, which involves minimal response or resistance, an environmentally aware occupant will be aware of this, and the resultant effect will be minimal carbon emissions. This concept could be further exemplified by the installation of live energy monitors, a feature we believe should be mandatory in every home. The success of PassivHaus isn’t only based on carbon emissions but at an economic level where the money saved from a reduction in energy bills is considered. The previous estimated energy bill P.A was calculated at £967.789 compared to the new value of £59.75. When this is considered over a significant cycle within the dwelling such as 15 years it amounts to £13620.585 saving from energy bills alone. However In many cases the cost of implementing PassivHaus strategies outweighs the benefits with the proportion of money saved in bills seeming very little in comparison to the installation costs. In some countries monetary reimbursement schemes exist to make the PassivHaus route seem more attractive a route the UK should potentially explore. With the inevitable increase in environmental pressures over the horizon the number of passive house designs in the UK can only increase, this will create a knock on effect as more architects and builders become aware and practised in this very stringent art of PassivHaus creation. Our re-design of a cavity wall based PassivHaus was very successful considering no previous site and design preparations were made. The calculations taken may have some small indescrepencies due to a certain level of estimation required, however with the installation of a MVHR system our calculation for Qventilation became considerable more accurate than previously with the dwelling. However the high cost of our re-design may make the proposed improvements financially unviable.

 


Equations

146  

 


Environmental Science