Issuu on Google+

Alexander Baldwin-Cole – Site and Solar Analysis

Page 1

(top left) A Diagram showing the overheating periods, due to low angle sun. These are primarily felt in rooms that are south facing and have large glass panels. Which most of the façade of my building does, so solar shading will have to be used to protect the rooms from overheating and or other ways of cooling it down such as natural ventilkation.

(Left) Map of the landscape surrounding the building, which consists of Heavy forest, with small winding paths that lead to the various spaces that are cut into the forest. A site map showing the climatic effects on the site. The orange shape indicates the location of my building complex. This feels the effects of strong prevailing winds from the south west. Also cold winter winds from the North East. This means that the habitable spaces that face these wind directions will need to have Intermediate spaces, which regulate the conditions from inside and outside the building.

June 21st 0900 (S.Solstice)

June 21st 1200 (S.Solstice)

March/ September 21st 0900 (Equinox)

March/ September 21st 1200 (Equinox)

December 21st 0900 (W.Solstice)

December 21st 1200 (W.Solstice)

A study of the shadows created from the trees throughout periods in the year. I used Google sketch up to model the trees and set the height according to the estimated height of the trees on the site already. During the S.Solstice the trees don’t shade the south facing glass façade, so other solar shading will have to be used. In the W.Solstice when the warmth of the sun is needed to aid heating in the rooms, however the trees block it from entering into the ground floor. A heating strategy will need to be devised to heat the lower floor.


Alexander Baldwin-Cole – Proposed Building and Study of Zones within Building

Page 2

Stairs Gardens Dining room Circulation Zone Changing room

Gallery

Gardens

Changing room

Art Room

Stairs

Mud Room

Reception

Circulation Zone

Counselling

Kitchen Outside terrace Reception

Reflexology

Stairs

WC WC

Aromatherapy Counselling

Library Shiatsu

Circulation Zone Areas in need of Heating

Stairs

Acupuncture

Meeting Room Areas in need of Cooling

Directors office Staff Room

Zones with temperature fluctuations Relatively stable zones

There are many different factors within buildings which affect there ability to be sustainable. One of the easiest way to make a sustainable building is to design it with a passive design. This doesn’t allow for openings as the air pressure has to be maintained , I thought about using this idea concept during my initial planning, however I liked spaces which broke the boundaries between inside and outside. Instead I designed the building to allow for these spaces, which meant that I needed to be able to stabilize the transition zones. The Floor area of the proposed plan is 217m2 (approx), and the window are is 182m2 (approx), of which about 80% faces towards the south. The outcome of this is that the window surface amount doesn’t fall in the bracket of being15%-30% of the floor area. This is bad for heating as large amount of heat will be lost out of the windows, the best bet is triple glazing and other methods of heating the zones.

The diagram above, is one that I used during initial design development of the scheme, which I have smartened up. The circles are scaled to the size required for the room. I then started locating them around circulation zone based on their needs. E.g. all the Counselling rooms are on the southern side of the building facing the woods to get the most of the views, along with the Administrative rooms. As they should also enjoy working in the building, by being in a nice environment. The Blue spaces or zones that will need to be heated due to the nature of the Therapy activities in the spaces. E.g. the visitors feeling comfortably enough temperature wise to remove clothes and have a massages etc. The red indicates areas which will overheat and need to be cooled, such as the Kitchen and the office where lots of people and computers will work. The ark grey areas are places which I expect will fluctuate in temperature (hallways), while the light grey circles are zones which will be relatively stable in temperature.


Alexander Baldwin-Cole – Form of Building, Identification of Trouble Spots and Microclimate

Page 3

A 2.7m Retaining wall, High Thermal mass. The Gallery and the Communal dining rooms, due to being pretty much empty, struggle to stay heated. Having them located above the kitchen allows the excess heat to warm them.

On the southern façade, solar shading is used to reduce excess heat in the summer. I designed it to follow the same form as the façade of the building. I also removed parts of the solar shade, where sun is needed to warm the thermal mass.

C B

Natural lighting. Slits in the roof allow in diffused light. The stacks act as light tubes directing light down into the heart of the building.

Micro-climate created outside the entrance to the lower floor. The trees and the sloped ground create a shelter from the winds (especially the winter winds). However during the winter no direct sun reaches this zone to warm it up. The heat comes from the thermal mass of the building, which stabilizes the temperate difference of the inside and outside.

A Retaining Wall

C B C

Red bricks

B In summer kitchens excess heat will be absorbed by the retaining walls, to stop overheat and also be drawn out through stack ventilation.

A

Lots of south facing glass means this room should be very hot. As the floor and retaining wall are made of concrete (thermal mass) this will keep the zone cool in the summer. In the winter heat will rise out of the ground floor of the building to keep the zone warm.

2.7m Retaining wall, High Thermal mass.

Excess heat from the Staff office will be absorbed by the surrounding thermal mass.

There are many zones of interest throughout the forest, like the one above which is the wood garden. These zones are individual microclimates. The retaining wall acts a shield for the cold winter winds. While the thermal mass of the red stone bricks, keeps the temperature of the zone stable and habitable both in the summer and winter.

C B

A

Partially south facing, the inhabited rooms (therapy and administrative) make the most of the solar gain.

Geothermal heat spots below the stacks opening help to increase the rate of ventilation. They also warm the central core of the building. The Therapy rooms need to be a comfortable temperature, so geothermal heat is used to keep them warm. This also helps in the natural ventilation (see stack diagram)


Alexander Baldwin-Cole – Light Strategy Proposal

Page 4

I studied the affect the sun would have on the building, by geo locating a sketch up model and setting the timing to various points of known overheating and under heating e.g. winter. What I found was due to the orientation of the building, and the large amounts of glass, there are problems with overheating. At first i aimed to just have a large solar shade that would cover the majority of the south facing façade. This would stop the spaces overheating in the summer. However I also want the sun to warm the thermal mass during the winter. The outcome is to have an overhang over the windows which follows the shape of the façade, but to also have blinds that work between the double glazing’s. Not only does this allow the rooms to not overheat during the summer, it also means that the individual rooms can be customized in terms of light, to best fit the activities that occur in them. Jan 21st 9:00

Daylight Factor The dayli9ght factor is a measure of the quality of light in the room. It is based on the ration between illuminance from outside over illuminance inside as a percentage. The higher the percentage the more natural light is available in the room. Window area (4.32m2), Total are of surfaces (36.2m2), Double glazing Transmittance (0.65), Visible sky angle (60*), Average reflectance (0.4)(Mainly pale walls, ceiling and floor)

May 21st 9:00

(4.32/36.2) X ((0.65 X 60) / (0.40 X 0.40)) barrier for being acceptable.

= Average Daylight factor for room is 5.5% (Recommended is 5)%. This is the room with the smallest window, yet it is still over the

Shallow room depth allows the natural light to penetrate further into the rooms.

Stack ventilation tubes also act as light tubes, bringing light down into the centre axis of the building.

June 21st 9:00 The large rooms at the back of the building are the gallery, communal dining and the art room. As so can be lightly coloured especially the gallery. This allows the spaces to get more from the natural light entering through the two windows.

Blinds are located in between the double glazing. This not only increases the u-Value of the window, but also allows the individual rooms to have different qualities of light, dependent on the purpose of the room.

Small room behind façade has natural light coming in through long sky light and from main hall.

Kitchen gets some of the light from the stack ventilation tubes, from the large window. The purpose of the room however will need more light than that provides. So smaller light tubes will bring light into the very back of the building.


Alexander Baldwin-Cole – Natural Ventilation Proposal

This diagram is taken through Section CC

The first floor has a separate cooling strategy than the ground floor. Cross ventilation is used, fresh air is let in from vents at the bottom of the walls and is drawn through the rooms by heating the air with the natural heat from the central core and the activities that are occur in the building. This is needed as cross ventilation is highly reliant on wind, so by heating the air slightly it will escape through the top outlets and draw fresh air in through the lower inlets.

Page 5

Wind vane: This directs the stack away from the direction of the wind. This increases the air pressure which draws are through the building at a higher rate.

The Passive ventilation strategies rely on the difference in pressure between cold and hot air. This allows unwanted hot air to rise out of the top of building and draw in cold fresh air into the base of the building.

Fan: Also helps to draw air up the stack at a higher rate as is powered by solar panels, so it works best on days which there is a high Solar element e.g. the summer where ventilation is needed most.

The stacks also act as a double head space and let daylight to penetrate down into the core of the building. Daylight also enters through other spots of diffused glass in the roof, where there aren’t stacks but daylight is still needed.

Air inlets

During days the lower inlets are left open to allow the rooms to draw the air up and into the rooms. In the summer nights the top inlets are opened to allow the cool air to cool the thermal mass and to let all the hot air left in the building from the day to escape, thus cooling down the buildings central core.

The air inlets do not pass through the geothermal pipes as the diagram may indicate. The pipes are instead located in between the small spots of geothermal heating. The air passes by the thermal mass so its temperature is modified slightly. This is mainly for in the summer, the hot air from outside is made cooler, by transferring its heat into the thermal mass before entering the building “Labyrinth Cooling”.

Geothermal Pipes. By going down 2.5m down the ground is a stable 15 degrees. This temperature remains constant throughout all season. The heat is transferred into the therapy rooms as well as below the stacks which help to increase the ventilation.

The heating of the floor is needed mainly in the winter, as the fresh air will be very cold and will especially in the therapy rooms cause the temperature to drop. The building will warm up throughout the day, but with using an electric control system the geothermal heat can be used to heat up pipes of cold water. These can be allowed to heat up when the people in the building want them to, such as just before the building opens so that is a good temperature when it opens. The same electronic system can be used to regulate which and when the inlets open.

The Kitchen is the warmest part of the building and so needs cooling. It is also located at the back of the complex so needs to be ventilated. This is done by drawing air in through inlets at the front of the building. Fans help draw the air in through the inlets and into the heart of the building.


Alexander Baldwin-Cole – Construction Detailing and U-Values

Choice & Sourcing of Materials

Corten steel exterior cladding

limecrete roof/ Floor White multiply board interior cladding Water proof membrane Load bearing beam

When choosing materials, you need not only to consider there ability as a structural element but also in terms of their affect to the environment. Some of the things I considered:    

How well they performed the structural job. How locally can they be sourced. How well do they contribute to the Passive design. What is the energy use required to produce them.

Page 6

Winter_ During the winter the thermal mass floors will be subject to low angled southern sun, heating them up. Also heat will be transferred into them by geothermal heating in previously identified spots. During the night The heat then is released into the building where is stabalises the temperature, this is much more important to the zones that will be used as soon as the building is open (administrative zone).

Roof

Load bearing, breeze blocks (high Limecrete: I chose to stick away from concrete as thermal mass. limecrete does all the same things as concrete (sturdy, high thermal mass), but without the high carbon foot Cavity with wool Insulation print and is also a much more breathable material, so will Double glazing help to stabilises the internal temperatures. Blinds

Water proof membrane

Corten steel exterior cladding

Ground level

Floor screed rigid insulation Limecrete slab foundation

1

2

3

4

5

10 Centimetres

Material Depth Limecrete – Low 260mm Density Internal 20mm Insulation Interior 20mm claddingWood Cladding: I only use a small amount of wood, as It produces next to no thermal advantages and is expensive Polyboard and very bad for the environment. The small amount that has been used can be sourced locally in Kent. Total U-Value = 0.48 W/m^2k Double glazing: I wanted to reduce the carbon foot print of the project but still get the passive solar benefits. The extra insulation which would have come from the extra layer of glass will be replaced by having internal blinds between the layers of glass. Thus increasing the U-Value of the windows, while also allowing the person in the room to change the light amount to there specifications.

Conductivity 0.33 0.023 0.21

This meets the requirements for a new build.

Wall

Material `Depth Conductivity External 20mm 0.5 Cladding – Corten Steel Water proof 20mm 0.036 High Thermal mass memebrane The building’s main strategy for regulation temperature is Breeze block 80mm 0.49 based on exposed thermal mass (floor and ceiling) which (medium will help to stabilises the internal temperature. As will the Density) 0.042 high retaining wall at the back of the building which will Cavity filled with 80mm Mineral Wool bring a stabilized temperature to the more overheated BreezeBlock 80mm 0.46 areas of the building. (Medium Density) Summer- During the summer days the thermal mass will Internal 20mm 0.21 absorb excess heat and can be stored in either the Cladding limecrete, the retaining wall or the breeze block walls. Polyboard While at night the excess heat can radiate out of the stack and cross ventilation system, thus bringing it down to a Total U-Value = 0.30 W/m^2k low temperature ready to absorb heat during the next day. This meets the requirements for a new build.


Climate II