Passivhaus: Air tightness, how safe is it?

A I RT I G H T N E S S HOW SAFE IS IT?

Contents 1. Introduction

1

2. The effectiveness of airtightness (Group experiment overview)

3

3. Airtightness and indoor air quality (IAQ)

5

4. The reliability of MVHR

7

5. Case studies

9

6. Solutions and preventions

11

7. Conclusion

13

8. Appendix

15

9. References

25

10. Bibliography

27

Group-work

Cover photo: Marsh Flatts Farm (Hart C, 2019) S17113623 Technical Investigation (Arc6012)

A I RT I G H T N E S S HOW SAFE IS IT? CHIQUITA HART

1. Introduction

The rise of the energy efficient home

In recent years, architects have become more focused on the environmental impact that housing has on the planet. According to Architects Declare, ‘nearly 40% of all UK Carbon emissions are a product of the building and construction industry’ (UK Architects Declare Climate and Biodiversity Emergency, 2019).

With energy efficiency being the main target, Passivhaus has become an increasingly popular solution in the industry.

To achieve Passivhaus standards there are key principles that should be considered from the beginning of the design process. These include: • Super insulation • Highly reduced thermal bridges • Good window design • Good ventilation strategy • Efficient shape • Consideration and analysis of orientation and overheating risk • Airtightness The airtightness of a Passivhaus building could arguably be considered one of the most essential standards to meet. Passivhaus plus states that 'Home energy use is responsible for approximately 27% of UK carbon dioxide (CO2) emissions and poor airtightness can be responsible for up to 40% of heat loss from buildings' (Jaggs and Scivyer, 2009, p1). Therefore the more airtight a building is, the less likely heat is to escape any cracks and gaps.

This means that the building becomes like an airtight container, retaining the heat of the house inside and relying on mechanical ventilation heat recovery systems (MVHR) in order to ventilate the building and prevent any overheating.’The Passivhaus airtightness target is < 0.6 ACH-1 @ 50 Pa for new build projects and < 1.0 ACH-1 @ 50 Pa for EnerPHit refurbishment projects.’

This compares ‘UK Building Regulations, where a maximum air permeability of 10m3/hr/m2 @ 50 Pa is commonly permitted. Hence the Passivhaus airtightness requirements for new builds are some 15 times more onerous than UK Building Regulations, while insulation requirements will typically only

be 3 to 4 times more demanding than Building Regulations.' (Passivhaus Trust, 2015, p24). This being said, as the number of ecohomes increase and the building regulations for airtightness become stricter, what are the risks of having an airtight home?

‘Home energy use is responsible for approximately 27% of UK carbon dioxide (CO2) emissions’

P. 02

Fig.1 Architects Declare poster. Source: ArchitectsDeclare (n.d.)

2. The effectiveness of airtightness (Group experiment overview)

Passivhaus trust states that, ‘Airtightness often appears

to be the most difficult element to achieve in Passivhaus projects, yet once a robust airtight design is in place, delivery is primarily about rigor and attention to detail.’

(Jennings, 2019). Hence the reason for airtightness testing. Testing airtightness is usually done at several stages during construction. Airtightness testing of a sample of newly completed dwellings is a requirement of Building Regulations in England and Wales, and Northern Ireland (and only a requirement in Scotland if a target better than 10 m3/h.m2 at 50 Pa has been set) (Jaggs and Scivyer, 2009, p26). This test highlights any air permeability (leakages) within the building or house and allows the construction workers to fill any of these gaps or holes that make themselves present.

AIRTIGHTNESS TEST • Allows air leakages to make themselves present • Useful at several stages of construction • Is now a requirement of Building Regulations

To truly test the effects of creating a building envelope, as part of a group we recreated this airtightness test by building a ‘room’ from insulation board. This ‘room’ contained a small window, allowing a heater to be placed on the inside to see how sealing this box with specialist tapes affected the time taken for the ‘room’ to cool back down to the original room temperature. Our results showed that at a thickness of 25mm insulation, it took a total of 58 minutes to cool down, reaching a maximum temperature of 34.4°C with a U-value of 0.880W/m2.K. When increasing the insulation to 75mm in thickness, the total cooling time measured up to 125 minutes with a lower U-value of 0.408W/m2.K. To consider how gaps within a house or building affects heat loss, the group decided to gradually add holes into the boards of insulation, increasing the diameter of the holes as we progressed. Evidently, these results showed that air leakages lead to a lower reach in temperature of 30°C, as well as a faster temperature drop with the highest drop in temperature being 0.6°C. Overall these results suggest how airtightness leads to higher reaches in temperature for longer periods of time, and therefore it takes longer for an airtight room to cool down, due to the lack of air permeability.

Fig.2 Airtightness test. Source: RIAS (n.d.). Airtightness Testing.

- The highest drop in temperature between each minute was 0.6 oC. The results would indicate that when more holes are added, the quicker the time it takes for the temperature drops and therefore heat loss to reach the same temperature as the temperature.

Aexternal graph to show experiments

1-5 overlaid to compare the temperature

at 25 degrees Celcius.

50

A graph to show experiments 1-5 overlaid compare the 1-5 temperature at compare 25 A graph to showtoexperiments overlaid to the degrees celcius temperature at 25 degrees Celcius.

45 40

TEMPERATURE (OC)

35 30 25 20 15 10 5

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88 91 94 97 100 103 106 109 112 115 118 121 124

0

TIME (MINUTES) External temperature

25mm no holes

75mm no holes

75mm + 5.1mm hole

75mm + 5.1mm x 2

75mm + 5.1m x 4 Refer to Fig. 6 in Appendix (Groupwork) for referencing.

GROUP RESULTS The graph above shows the time taken for each experiment we did to cool to 25°C. This allows us to more accurately compare the airtightness as the points are comparable.

- 75mm with 4 holes: 17.2 minutes - 75mm with 2 holes: 24.5 minutes - 25mm with no holes: 42.5 minutes - 75mm with 1 hole: 62.6 minutes - 75mm with no hole: >125 minutes Looking first at the test run with 75mm its clear that the fewer the holes, the greater the airtightness and therefore reduced heat loss. Furthermore, the improvement in airtightness increases at a greater than linear rate, which can be seen from the graph to the right, as the number of holes reduces.

P. 04

3. Airtightness and indoor air quality (IAQ) Air pollutants and their health risks

New build homes focus on being energy efficient and therefore aim for

airtightness within these houses. It has always been evident that indoor air quality is important within a building. In recent years, research shows that on average we spend ‘90% of our time indoors and a significant chunk of that in our homes’ (Wilson and Piepkorn, 2014). However, over the years a number of reports have been released linking airtightness to a series of health problems such as allergic and asthma symptoms, lung cancer, chronic obstructive pulmonary disease (COPD), airborne respiratory infections, cardiovascular disease (CVD) (Who.int, 2018) and odour and irritation (sick building syndrome symptoms).

Nonetheless before we continue it is important that we understand the causes of poor indoor air quality.

‘Appropriate IAQ can be defined as the absence of air contaminants which may impair the comfort or health of building occupants’ (Rousseau, 2003). Poor indoor air quality (IAQ) can be caused by things such as breathing (the build-up of CO2) poor heating systems, dampness and even daily household activities such as cooking, washing (Fig.3) and cleaning. According to WHO, ‘around 3.8 million people a year die from the exposure to household air pollution.’ (Who.int, 2018). Within our homes, there are a range of different pollutants.Volatile organic compounds (VOCs) can be a range of evaporated substances, including formaldehyde which can be emitted by building materials and furnishings such as carpets, paints and cabinet finishings. Professor of the built environment at Reading University’s school of construction management and engineering predicts that ‘by 2050 – the date by which Britain is supposed to have achieved an 80% cut in carbon emissions – declining indoor air quality could have led to

an 80% rise in the 5.4 million people already suffering from asthma.’

(Campbell, 2015). Subsequently, as these new build homes become increasingly airtight and the amount of time spent indoors rises, we are more likely to ingest these pollutants therefore deteriorating our health and aggravating those with asthma and respiratory issues.

However, whilst there are many reports raising concerns with the increase in airtight homes, ‘many occupants feel that the quality of air supplied by the effective ventilation system is very good, and this can help to reduce the risks of allergies and other health problems.’ (Why choose Passivhaus, 2013, p.6) . Head of Sustainable Investment for Orbit Heart of England, John Barnham believes that, ‘Improved health and well-being are also recognised and attributed to Passivhaus, as well as improved occupier satisfaction with their home’ (Why choose Passivhaus, 2013,p11). Moreover, high volumes of moisture in a room or building can create a variety of problems including mould which breeds toxic air pollutants. Moisture

Fig.3 VOCs in living environments. Source: MEARU (2016)

is formed by condensation which occurs when warm air meets a cold surface. Nevertheless, according to Passivhaus standards, the temperature within a Passivhaus remains even, therefore condensation is more difficult to achieve. This can be seen from the group experiment where the 25mm insulation remains at ≈34°C for approximately 9 minutes. Passivhaus is only really affected when humidity levels increase from excessive activities such as boiling water or showering. Despite this, Professor Tim Sharpe, head of The Mackintosh Environmental Research Unit (MEARU), said: ‘Poor indoor air quality, particularly in bedrooms, is hard for people to detect.’ (Bradford, 2016). To expand, poor IAQ is something that is not tangible and therefore rises in pollutant levels is almost impossible to tell without the correct equipment.

This is potentially why illnesses such as sick building syndrome (SBS) where building occupants experience acute symptoms and discomfort that are apparently linked to the time spent in the building, but for which no specific illness can be assigned (Indoor Air Facts No. 4 (revised) Sick Building Syndrome,

1991), are difficult to understand as the occupant cannot see what is affecting them. The Mackintosh Environmental Research Unit (MEARU) conducted an experiment on 200 new build homes and warned that ‘people need to be aware of the

build-up of CO2 and other pollutants in their homes, and their potential impact on health.’ (Bradford, 2016). Whilst MEARU and other specialists advise that it is important that these houses are ventilated properly, and people should open

windows during these daily activities such as cooking and cleaning, others believe that this is not enough to combat these issues, expressing how ventilation systems need to be better understood in order to prevent any threats to human health.

‘Each year, close to 4 million people die prematurely from illness attributable to household air pollution’ - WHO (World health organization)

P. 06

4. The reliability of MVHR Can mechanical ventilation systems create a suitable IAQ?

Whilst we are covering the topic of airtightness it is

crucial that we discuss the ventilation system within Passivhaus and eco-homes which aim to provide a high IAQ. Mechanical ventilation systems are used within airtight and Passivhaus homes to help circulate new air into the house and also to ensure that over-heating does not occur. Within the Passivhaus Plus journals, they consistently express the need for a mechanical ventilation system to be installed correctly, and emphasise the importance for the occupant to understand how and when to use the system. Galvanised ducts are commonly blamed for health issues related to air pollutants as they are what help the air circulate within the house. However, it is only problematic if the duct is not installed correctly as any gaps or issues will lead to worsen dust build-ups and therefore affect the air filters (Fig.4). Galvanised ducts are known to be naturally antibacterial and therefore it is difficult for mould to occur. A brief example of the resilience of these ducts is shown at the 25th Passivhaus anniversary where the first Passivhaus (Dr. Wolfgang Feist, 1991) MVHR system was reviewed and they found that all ducts were clean and free from moisture (Passivhaustrust.org.uK, 2016). However, there are many experts who believe that relying on mechanical ventilation is not the solution to ensuring a high indoor air quality within your house.

Tom Woolley expresses his concern for the dependency within his book, ‘Building Materials, Health and Indoor Air Quality: No Breathing Space?’, saying that, ‘An increasing dependence on mechanical ventilation may exacerbate, rather than resolve, IAQ (Indoor air quality) problems’ (Woolley, 2016,p125). In 2015 a survey of housing providers found that '53 out of a possible total of 75 organisations (70%) reported experiencing at least one instance of overheating in their housing stock in the last 5 years' (The challenge of shape and form, 2019). Over-heating within an airtight home can lead to moisture issues which then can lead to mould problems, therefore hindering the IAQ of these new build homes.

On the other hand, Bob Krell, publisher of Healthy

Indoors Magazine says that, ‘You can do everything right; seal the home, install perfectly designed ventilation and filtration systems, but still have toxic indoor air if the wrong materials are used.’ (Beere, 2018). In other words, the reports linked to airtightness and poor health, focus on the difficulties of removing these indoor pollutants from a sealed building, when they perhaps should be focusing on what materials are causing these pollutants and what can be used instead to increase the IAQ of our homes.

‘You can do everything right; seal the home, install perfectly designed ventilation and filtration systems, but still have toxic indoor air if the wrong materials are used.’

- Bob Krell, publisher of Healthy Indoors Magazine

Fig.4 Filters which have become full of dust (Marsh Flatts Farm). Showing how MVHR needs consistent upkeep. Source: (Hamid A, 2019)

Fig.5 MVHR system at the Marsh Flatts Farm. Source: (Hamid A, 2019) P. 08

5. Case Studies The first Passivhaus social housing in the West Midlands

To examine these ideas it is es-

sential that we also investigate existing new build projects which are examples of the Passivhaus standard. Recently I visited the first social housing development in the West Midlands to follow the Passivhaus certification route, Sampson Close, Coventry. Giving performance U values less than 0.15W/ m2k to walls, floors and roofs, every home in Sampson Close uses thick insulation made from recyclable materials. The main source of ventilation within these homes is the mechanical ventilation recovery heat system (MVHR). These houses are extremely energy efficient, costing tenants as little as £2 per week to heat a two bedroom flat based on current tariffs. (SC Case Study, 2019) In addition to this, ‘the method of construction utilised results in an energy-saving of up to 90% when compared to traditional housing construction’ (SC Case Study, 2019).

These are all valuable benefits to the Passivhaus standard and show how an airtight home leads to less money spent on heating the house. However, during the property’s viewing, some complained that the house felt ‘too claustrophobic’ and was not ‘a comfortable temperature’. In 2016 Colin Marrs wrote an article for Architect’s Journal titled, ‘Airtightness blamed for health risks in homes’, where he states that only 2 out of 55 people ventilate their homes correctly, (Ing, Jessel and Waite, 2019) showing how these homes can lead

Fig.6 Sampson Close, Coventry. Source: (Roper-Hall S, 2019) to an uncomfortable temperature as well as a lack of high IAQ. On the other hand, I also had the opportunity of visiting David Brooke’s Marsh Flatts Farm which is a new build privately owned home, aiming for Passivhaus certification. The owner of the house who has been very active in the phases of constructing his home expresses that there is ‘No need to open windows for ventilation (especially beneficial in noisy

locations)’ and the ‘Incoming air is filtered, removing insects and particulate pollutants such as pollen’ (Brooke, 2019) making it a healthy home. Brooke’s responses could perhaps suggest how the involvement in the process of aiming to become Passivhaus certified is what allows a better understanding of how to know when the IAQ has deteriorated and how to use the ventilation system to rectify any issues.

Fig.7 Sampson Close, Coventry. First Passivhaus social housing in the West Midlands.

Source: (Hart C, 2019)

Fig.9 Marsh Flatts Farm, solar powered energy. Source: (Hart C, 2019) P. 10

6. Solutions and Preventions What can we do to prevent health risks Home owners have complained that the manual and instructions to use these mechanical ventilation systems are too hard to understand and operate themselves. What can we do to solve these issues to ensure a high level of IAQ in these airtight homes?

Proposed solutions:

1

‘Don’t over complicate user guides and try to familiarise on ‘move in day’. (Jennings, 2019,p22).

To ensure that all new build homeowners are aware of how to monitor air quality and how to keep the property well ventilated at least one member from each household could be required to take a test to confirm that they understand the system and what to do in a multiple of system failure scenarios. This is essential as air quality is something that the homeowner cannot identify by sight, therefore understanding the system is important to prevent any of the issues previously explored.

2

In order to ensure that the ventilation system is working effectively, many recommend that maintenance and services are scheduled on a frequent basis in order to upkeep the system and ensure that a high indoor air quality is being reached.

3

‘Build tight and ventilate right’ (Environmental handbook for building and civil engineering projects, 1994). Whilst airtight homes are heavily dependent on MVHR systems, it is recommended that you open windows during activities where pollutants are at their highest, i.e., cooking, cleaning and washing. This can introduce clean air into your home naturally, allowing any pollutants to easily escape.

“It was a huge folder and it just went into the drawer and that’s where it stayed. It was designed for someone who was mechanical. It wasn’t any use to me.”

- Margaret and John Trainer, from East Renfrewshire, found their MVHR manual difficult to understand (Trainer, 2016)

P. 12

7. Conclusion Overview

Overall, based on the evidence

provided airtightness is very effective and can help reduce energy bills as well as in some instances increase the comfortability of the house for the occupant. However, whilst Passivhaus standards for airtightness help us to reach our carbon net zero goals, it is undeniable that airtightness also poses some serious questions about whether it is a potential threat to our health.

With an increasing amount of reports regarding the link between airtightness and health issues, one could argue that further actions need to be taken to investigate how we can tackle the issue. Following on, as building regulations become stricter it is essential that ventilation is considered more to accommodate for the lack of air permeability. In addition to this, one may argue that a thorough investigation also needs to be considered in terms of building materials and furnishings. Within these new build homes materials appear to be chosen based on cost and aesthetic, neglecting the impact they have on IAQ and the impact this can have on humans.

Nonetheless, whilst there are a combination of issues which seem to be associated to the lack of clean air in airtight homes, it is the responsibility of all who are in the home design and construction industry to ensure that the occupants health is a priority in the instance of all design related decisions.

Fig.10 Potential app idea. Source: (Hart C, 2019)

Finally, a potential solution is to

include meters within these airtight homes which read the harmful pollutant levels within the air. Knowing the increased use of technology in homes, especially to control heating and electricity, it could be beneficial to have an app connected to these IAQ readers, enabling the occupants

to be notified when to open a window or turn on the MVHR system. In addition to this the app could allow the occupant to notify a specialist when the MVHR system is not working and also have contact details for people who are able to visit the property and fix any issues as soon as a problem is reported within the app.

8. Appendix

P. 14

APPENDIX: Group work

Authors: Ahmed Hamid, Chiquita Hart, Chloe Walpole, Sophie Roper-Hall

Passivhaus

The Passivhaus principle‘s originated in Germany in 1991 by Dr. Wolfgang Feist. It consists of a set of design standards which were established to create low energy efficient buildings.

The key principles include: Airtightness Super insulation Highly reduced thermal bridges Good window design Good ventilation strategy Efficient shape Photo: Level 6 Architecture students taking part in a Passivhaus seminar. Source: Authors (2019)

Analysis of orientation

Site visit

Our groups first introduction to Passivhaus in practice was when we visited two buildings which had been built to meet Passivhaus certificatoin.

Marsh Flatts Farm

Sampson Close

The second Passivhaus build we visited was in Coventry. It is a social housing scheme that was built in 2011 by Orbit Homes and is comprised of 18 apartments and 5 houses. It used pre-assembled walls, floors and roof panels to keep costs and time low. Construction time was in fact cut so low that it took just 1 week to erect the first 3 houses.

It uses large solar panels to heat the domestic hot water and uses a On arrival it was immediately district gas fired heating system. apparent that the interior temperature was a comfortable On arrival it was evident that the environment to be in. We were scale of the project was far denser then given a thorough tour around than that of Marsh Flatts farm. the entire house and were shown However, we didn’t get a chance to how the mechanical ventilation go inside the buildings so could not heat recovery system worked. experience the internal environment.

The first building we visited was in rural Derbyshire which was a privately-owned new build. It was situated on a disused dairy farm and replaced what was once the farmhouse. The construction of the building is made from a combination of cavity wall masonry and SIP’s panels, with the aim of meeting Passivhaus certification standards.

Photos: Marsh Flatts Farm, MFF Window and Sampson Close. Source: Authors (2019)

01

Method

1.

Image showing a 5cm edge of tape being left.

Source: Authors (2019)

2. Image showing the tape being cut in order to fold around corners. Source: Authors (2019)

Creating an airtight box

around a circular shape.

To investigate this further we completed an experiment in groups to understand how the energy efficiency performance can be improved, other than putting in lots of insulation. The variable we chose to explore in more depth was airtightness.

Method for reducing airtightness

In order to test airtightness effectively, we first looked at how we 5. To do this we drilled a hole into could make a box completely airtight the middle of the one side of surrounding a 1:1 scale window, the box, which was 5.1mm in using 25 mm thick insulation. To diameter, and repeated do this we used industry standard the experiment. airtightness tapes including: We then drilled another 5.1mm “Sicrall 60” for straight edges hole on the opposite side of the box “Rissan 60” for flexible edges and repeated the experiment again.

Lastly, we increased the number of 1. It should also be noted that, 5.1mm holes to 4 and repeated the under advice from the manual experiment for a final time. supplied with the tapes (SIGA, 2019) a 5cm edge of tape was left round the edges of the box to allow for maximum coverage and therefore effective airtightness.

3.

Image showing a 5cm edge of tape being left around the window. Source: Authors (2019)

4.

Image showing the hole made and taped round.

Source: Authors (2019)

2. In addition to this, we ensured that a 5cm overlap of tape occurred at each corner, and again following instruction from the manual, (SIGA, 2019) cut the tape to create a fold so no gaps for air to pass through were present. On the bottom of the box we made sure that there was continuous tape all the way underneath so that the heat could not escape from the underside.

3. Around the window we used the same technique making sure there was enough tape overlapping the insulation and window so that there were no gaps for air to get in.

4. Next, we made a hole in the lower of one side of the box in order to fit the extension lead so that the heater could be plugged in. Around the hole we used “Rissan 60” as it was to go

After the box was complete, we made sure there was a thermometer inside, and the window was shut correctly. After this we then turned on the heater and waited for the temperature inside to reach 30 degrees Celsius. As soon as the required temperature was reached, we turned the heater off and recorded, in intervals, the amount of time it took to cool back down to room temperature.

We then added an extra 50mm of insulation on top of the original box and repeated the experiment, keeping the controlled variables consistent.

These two results show the direct link between the amount of time it takes for the box to cool down with 25mm of insulation or 75mm of insulation.

P. 16

5. Image showing the hole being drilled. Source: Authors (2019)

The next step we took was to investigate whether adding varying sized holes would affect the airtightness and therefore the heat loss.

02

Results Insulation (no holes) 25mm insulation25mm (no holes)

Experiment 1

35 30 25 20 15 10 5

The highest drop in temperature between each minute was 0.4oC. The results indicate that most heat is lost the higher the temperature but the overall heat loss steadily declined until it reached the same temperature as the external one.

Experiment 2 Next we added 50mm of insulation.

From the data collected the following can be observed:

The results would indicate that the thicker 75mm insulation is more effective than the 25mm insulation as the drop in temperature was consistently lower and the cooling time was much longer. However the test was not directly comparable as the temperature it was initially heated to was higher.

58.00

55.00

52.00

49.00

46.00

43.00

40.00

37.00

34.00

31.00

28.00

25.00

22.00

19.00

16.00

Figure 1. Graph to show 25mm Insualtion with no holes. Source: Authors (2019)

U value calculations for 25mm insulation: R = l/Îť R = 0.025/0.022 R = 1.136 W/m2. K. U-Value = 1/(Rso + Rsi + R1) U-Value = 1/(0.060 + 0.120 + 1.136) U-Value = 0.880 W/m2.K. * (Rso + Rsi values taken from Architects Pocket Handbook wall value)

75mm insulation75mm (no holes) Insulation (no holes) Temperature (celcius)

External temperature

50 45 40 35 30 25 20 15 10 5 0

1.00 6.00 11.00 16.00 21.00 26.00 31.00 36.00 41.00 46.00 51.00 56.00 61.00 66.00 71.00 76.00 81.00 86.00 91.00 96.00 101.00 106.00 111.00 116.00 121.00

TEMPERATURE (OC)

- The highest drop in temperature between each minute was 0.2 oC.

13.00

TIME (MINUTES)

- The temperature reached a maximum of 43.3oC. - The total cooling time from start to finish was incomplete but measured up to 125 minutes (2 hours 5 mins).

10.00

- The total cooling time from start to finish was 58 minutes.

7.00

0

4.00

- The temperature remained constant for 1 minute between 3-4 minutes and 12-13 minutes.

External temperature

40

1.00

- The temperature reached a maximum of 34.3oC.

Temperature (celcius)

TEMPERATURE (OC)

For the first experiment we made the box with 25mm insulation and drilled no holes. From the data collected the following can be observed:

TIME (MINUTES) Figure 2. Graph to show 75mm Insualtion with no holes. Source: Authors (2019)

U value calculations for 75mm insulation: R = l/Îť R = 0.075/0.022 R = 3.409 W/m2. K. U-Value = 1/(Rso + Rsi + R1) U-Value = 1/(0.06 + 0.12 + 3.409) U-Value = 0.278 W/m2K * (Rso + Rsi values taken from Architects Pocket Handbook wall value)

03

Results

After comparing the variances between different thicknesses of insulation, our next step was to test how adding varying sized holes would affect the air tightness and therefore heat loss.

75mm insulation (5.1mm hole) (5.1mm hole) 75mm Insulation

Experiment 3

- The total cooling time from start to finish was 82 minutes

External temperature

40 35 30 25 20 15 10 5 0

1.00 4.00 7.00 10.00 13.00 16.00 19.00 22.00 25.00 28.00 31.00 34.00 37.00 40.00 43.00 46.00 49.00 52.00 55.00 58.00 61.00 64.00 67.00 70.00 73.00 76.00 79.00 82.00

- The temperature reached a maximum of 35.3oC.

Temperature (celcius)

TEMPERATURE (OC)

We then drilled a 5.1mm hole into one side of the box. From the data collected the following can be observed:

- The highest drop in temperature between each minute was 0.4 oC.

TIME (MINUTES) Figure 3. Graph to show 75mm Insualtion with 1 hole. Source: Authors (2019)

The results would indicate that the 75mm insulation with 1 hole is more effective than the 25mm insulation with no holes as the length of time it took to reach the same temperature at the external temperature was longer than the 25mm insulation with no holes.

Experiment 4

75mm insulation (2 holes) (2x 5.1mm hole) 75mm Insulation

We then drilled another 5.1mm hole into the opposite side of the box.From the data collected the following can be observed:

20 15 10 5

41.00

39.00

37.00

35.00

33.00

31.00

29.00

27.00

25.00

23.00

21.00

19.00

17.00

15.00

13.00

11.00

9.00

7.00

5.00

0

TIME (MINUTES)

Figure 4. Graph to show 75mm Insualtion with 2 holes. Source: Authors (2019)

P. 18

The results would indicate that the heat loss is greater with the additional hole than both the 25mm with no holes and the 75mm with 1 hole.

25

3.00

- The highest drop in temperature between each minute was 0.5 oC.

30

1.00

- The total cooling time from start to finish was 42 minutes

Series2

35

TEMPERATURE (OC)

- The temperature reached a maximum of 30.7oC.

Series1

04

Results Experiment 5

75mm Insulation (4x 5.1mm hole)

We then drilled two more 5.1mm hole into the both sides of the box.

From the data collected the following can be observed: - The temperature reached a maximum of 30.3oC. - The total cooling time from start to finish was 31 minutes - The highest drop in temperature between each minute was 0.6 oC. The results would indicate that when more holes are added, the quicker the time it takes for the temperature drops and therefore heat loss to reach the same temperature as the external temperature.

50

Figure 5. Graph to show 75mm Insualtion with 4 holes. Source: Authors (2019)

A graph to show experiments 1-5 overlaid compare the 1-5 temperature at compare 25 A graph to showtoexperiments overlaid to the degrees celcius temperature at 25 degrees Celcius.

45 40

30 25 20 15 10 5 0

1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88 91 94 97 100 103 106 109 112 115 118 121 124

TEMPERATURE (OC)

35

TIME (MINUTES) External temperature

25mm no holes

75mm no holes

75mm + 5.1mm hole

75mm + 5.1mm x 2

75mm + 5.1m x 4

Figure 6. Graph to show all experiments compared with each other. Source: Authors (2019)

05

Conclusion Comparing experiments 1-5

T S

The graph above shows the time taken for each experiment we did to cool to 25 degrees Celsius.

This allows us to more accurately compare the airtightness as the points are comparable.

- 75mm with 4 holes:

17.2 mins

- 75mm with 2 holes:

24.5 mins

- 25mm with no holes: 42.5 mins - 75mm with 1 hole:

62.6 mins

- 75mm with no hole: >125 mins

Looking at the test with 25mm no holes, its also clear that the level of insulation has a significant impact.

The results therefore show two things:

75mm Insulation Comparison 75mm Insulation Comparison 62.6

Number of holes

Looking first at the test run with 75mm its clear that the fewer the holes, the greater the airtightness and therefore reduced heat loss.

Furthermore, the improvement in airtightness increases at a greater than linear rate, which can be seen from the graph to the right, as the number of holes reduces.

24.5 17.2

Time (Minutes) Figure 7. Graph to show the non linear effect of heat loss by adding more insulation. Source: Authors (2019)

The first is that the greater the insulation, the more effective the airtightness.

The second is the fewer holes the greater the airtightness. It should also be noted that it wasnâ&#x20AC;&#x2122;t possible, in the time available, to complete the test on 75mm with no hole, due to it being in excess of double any of the other experiments. However, it can be deduced that it fully supports the above conclusions.

P. 20 06

Technical Detail 1:20 Technical Detail Section Scale 1:10

Timber Joist

Membrane

Glazing Unit Econorm or approved

1:10 TECHNICAL SECTION @A4 Window Cill PIR Insulation Siga Corvum 12-48 or similar approv Membrane

Airtightness tape to applied along edges Siga Fentrim or similar approved

Timber Cladding Concrete Block Work 100mm Mineral Dryitherm DRI Insulation 250mm

Figure 8. Technical detail to show an attempt at a window detail at Marsh Flatts Farm. Source: Authors (2019)

Marsh Flatts Farm

APPROVED GLAZING UNIT Having completed our group work experiments, we decided to test how BITUTHANE MEMBRANE technically drawing the techniques FLASHING OVERLAPPING we had used previously would look DRAINAGE PLANE like.

goes from floor to roof. In addition to this, Siga Fentrim airtightness tapes were applied to the edges as shown in the technical detail.

cavities are different to the previous technical detail which allow for better insulation within the walls and therefore make the building more efficient in retaining the inside CILL constant.

Since this didn’t achieve Passivhaus temperature WINDOW WINDOW SILL The technical section above is our certification, we decided it would AIRTIGHT TAPING attempt at a techical detail from the be important to draw a technical TO THE INTERIOR - 50mm passive houseCAVITY case study we visited in detail that does meet Passivhaus Derby on our field trip. However, after certification in order to compare TIMBER JOIST the blower door test was completed, them. This would allow us to see they found that theCLADDING airtightness didn’t where the differences lie and why TIMBER CAVITY (SERVICES) achieve the Passivhaus certification Marsh Flatts Farm may not have CONCRETE BLOCK standard. passed the test.

AIRTIGHTNESS WORK - 100mm BOARD The green dashed line represents the In the technical drawing below, MINERAL DRYITHERM PLASTER internal airtightness that continuously it can be observed that the wall INSULATION - 250mm 07

The technical section above is from

Technical Detail 1:10 Passivhaus certified wall detail APPROVED GLAZING UNIT CONTINUOUS INTERNAL AIRTIGHTNESS

BITUTHANE MEMBRANE FLASHING OVERLAPPING DRAINAGE PLANE

WINDOW SILL

WINDOW SILL

AIRTIGHT TAPING TO THE INTERIOR

CAVITY - 50mm

TIMBER JOIST TIMBER CLADDING

CAVITY (SERVICES)

CONCRETE BLOCK WORK - 100mm

AIRTIGHTNESS BOARD

MINERAL DRYITHERM INSULATION - 250mm

PLASTER Figure 9. Technical detail to show a correct Passivhaus window joint detail. Source: Authors (2019)

REFERENCES SIGA (2019) Manual for the professional craftsman. Siga Swiss.

BIBLIOGRAPHY Passvihaus Trust (2015) How to build a Passivhaus: Rules of Thumb. London: Passivhaus Trust. Available at http://www. passivhaustrust.org.uk/guidance_detail.php?gId=29#.W5orYvYnZlc [Accessed 18 September 2019] Passivhaus Trust (2013) Why choose Passivhaus? London: Passivhaus Trust. Available at http://www.passivhaustrust.org.uk/ guidance_detail.php?gId=15#.W5otIPYnZlc [Accessed 18 September 2019] All photographs, figures, graphs and technical details were produced by the authors of this document.

P. 22 08

BA (HONS) ARCHITECTURE Level 6 ARC6012 Technical Investigation

Group Submission â&#x20AC;&#x201C; Peer Assessment Peer assessment form Please give each member of your team (not yourself) a score under the headings below: Effort

Quantity/quality of work from the individual

Enthusiasm

Motivation/diligence of the individual

Teamwork

Selflessness/collaborative approach in working together

Productivity

Efficiency of output / effective contribution to the team

Please use a 1-10 scale for assessing performance: 9 - 10

Excellent

7-8

Very good

5-6

Adequate

3-4

Poor

1-2

Non-existent/very poor

Please remember this review is confidential and is not seen by your peers, only by staff involved in the module.

Please include this peer review sheet as an appendix at the end of your pdf report.

Name:

Chiquita Hart

Date:

15/12/19

Student name

Effort

Enthusiasm

Teamwork

Productivity

Sophie Roper-Hall

10

10

10

10

Chloe Walpole

10

10

10

10

Ahmed Hamid

10

10

10

10

Evidence / reflections Please use this space to provide reflections about how your team worked as evidence for the scores above to be taken into account by the assessors: Overall, we worked well and collaboratively as a team to produce the work. There was good communication from all group members as well as a positive attitude to achieve group tasks and assignments.

P. 24

9. References Beere, P. (2018). Is a Tight Home a Sick Home?. [online] Healthy Indoors. Available at: https://healthyindoors. com/2018/06/tight-home-sick-home/ [Accessed 22 Nov. 2019].

Brooke, D. (2019).Ventilation System. [Blog] Marsh Flatts Farm Self Build Diary. Available at: https://www.marshflattsfarm.org.uk/wordpress/?page_id=4375 [Accessed 7 Dec. 2019].

Bradford, E. (2016). Health warning over 'airtight' homes. [online] BBC News. Available at: https://www.bbc.co.uK/ news/uk-scotland-36134213 [Accessed 16 Nov. 2019].

Campbell, D. (2015). Asthma could be worsened by energy-efficient homes, warns study. [online] The Guardian.

Available at: https://www.theguardian.com/society/2015/sep/20/energy-efficient-homes-could-worsen-asthma [Accessed 22 Nov. 2019].

Environmental handbook for building and civil engineering projects. (1994). London: CIRIA and Thomas Telford, p.66.

Guide to Mechanical Equipment for Healthy Indoor Environments. (2003). Harvard University Press.

Indoor Air Facts No. 4 (revised) Sick Building Syndrome. (1991). [ebook] EPA. Available at: https://www.epa.gov/ sites/production/files/2014-08/documents/sick_building_factsheet.pdf [Accessed 2 Dec. 2019].

Ing, W., Jessel, E. and Waite, R. (2019). Airtightness blamed for health risks in homes. [online] Architects Journal.

Available at: https://www.architectsjournal.co.uK/buildings/airtightness-blamed-for-health-risks-in-homes/10014252. article [Accessed 26 Nov. 2019].

Jaggs, M. and Scivyer, C. (2009). A practical guide to building airtight dwellings. IHS BRE Press, p.1.

Jennings, P. (2019). How to build a Passivhaus. [ebook] Passivhaus Trust, p.24. Available at: http://www.passivhaustrust. org.uK/UserFiles/File/Technical%20Papers/ROT/How%20to%20build%20a%20Passivhaus_Chapters%201%20to%204. pdf [Accessed 14 Nov. 2019].

Jennings, P. (2019). How to Build a Passivhaus: Rules of Thumb. [ebook] p.24. Available at: https://www.docdroid. net/3xcGJf7/how-to-build-a-passivhaus-rules-of-thumb.pdf [Accessed 26 Nov. 2019].

Passivhaustrust.org.uK. (2016). Passivhaus News. [online] Available at: https://www.passivhaustrust.org.uK/news/detail/?nId=629 [Accessed 13 Dec. 2019].

Cutland Consulting Ltd and Eco Design Consultants Ltd (2017) Windows â&#x20AC;&#x201C; making it clear: energy, daylight and thermal comfort (NF78) Milton Keynes: NHBC Foundation. Available at https://www.nhbcfoundation.org/publication/windows-making-it-clear-energy-daylight-and-thermal-comfort/[Accessed 23 November 2019] The challenge of shape and form. (2019). [ebook] Milton Keynes: NHBC Foundation, p.16. Available at: https://www. nhbcfoundation.org/wp-content/uploads/2016/10/NF-72-NHBC-Foundation_Shape-and-Form.pdf [Accessed 26 Nov. 2019].

SC Case Study. (2019). [ebook] Ledbury: Jaga. Available at: https://www.jaga.co.uK/wp-content/uploads/2019/03/SCCaseStudy.pdf [Accessed 25 Nov. 2019].

Trainer, M. (2016). Pollutant warning over ‘airtight’ modern homes. [Accessed 20 Nov. 2019].

UK Architects Declare Climate and Biodiversity Emergency. (2019). UK Architects Declare Climate and Biodiversity Emergency. [online] Available at: https://www.architectsdeclare.com/ [Accessed 19 Nov. 2019].

Who.int. (2018). Household air pollution and health. [online] Available at: https://www.who.int/news-room/factsheets/detail/household-air-pollution-and-health [Accessed 17 Nov. 2019].

Why choose Passivhaus. (2013). [ebook] London, p.11. Available at: http://passivhaustrust.org.uK/UserFiles/File/ Why%20choose%20Passivhaus%202013%20FINAL.pdf [Accessed 22 Nov. 2019].

Wilson, A. and Piepkorn, M. (2014). Green Building Products, 3rd Edition. 3rd ed. Gabriola Island: New Society Publishers. [Accessed 22 Nov. 2019].

Woolley, T. (2016). Building materials, health and indoor air quality. n.d: Taylor & Francis, p.125. [Accessed 23 Nov. 2019].

Images Fig.1: ArchitectsDeclare (n.d.). ArchitectsDeclare Poster. [image] Available at: https://www.architectsdeclare.com/ [Accessed 6 Dec. 2019].

Fig.2: RIAS (n.d.). Airtightness Testing. [image] Available at: https://hemacnetwork.files.wordpress.com/2016/02/practice-note.pdf [Accessed 3 Dec. 2019].

Fig.3: MEARU (2016). The film aims to help more people become aware of the impact of poor ventilation on health and general living environments. [video] Available at: <iframe title=”vimeo-player” src=”https://player.vimeo.com/video/163384704” width=”640” height=”360” frameborder=”0” allowfullscreen></iframe> [Accessed 10 Dec. 2019].

Fig.4-9: (Hamid A and Hart C, 2019) Fig.10: Image of proposed app (Hart C, 2019)

P. 26

10. Bibliography Passvihaus Trust (2015) How to build a Passivhaus: Rules of Thumb. London: Passivhaus Trust. Available at http:// www.passivhaustrust.org.uk/guidance_detail.php?gId=29#.W5orYvYnZlc [Accessed 22 November 2019] Passivhaus Trust (2013) Why choose Passivhaus? London: Passivhaus Trust Available at http://www.passivhaustrust. org.uk/guidance_detail.php?gId=15#.W5otIPYnZlc [Accessed 22 November 2019] Cutland Consulting Ltd and Eco Design Consultants Ltd (2016) The Challenge of shape and form. Understanding the benefits of efficient design. (NF72). Milton Keynes: NHBC Foundation. Available at https://www.nhbcfoundation. org/wp-content/uploads/2016/10/NF-72-NHBC-Foundation_Shape-and-Form.pdf [Accessed 22 November 2019] Cutland Consulting Ltd and Eco Design Consultants Ltd (2017) Windows â&#x20AC;&#x201C; making it clear: energy, daylight and thermal comfort (NF78) Milton Keynes: NHBC Foundation. Available at https://www.nhbcfoundation.org/publication/windows-making-it-clear-energy-daylight-and-thermal-comfort/[Accessed 22 November 2019]

P. 27