Environmental Strategy in Urban Housing

Environmental Strategy Booklet Jessica G Cowan

3A

Environmental Caluclations These caluclations will be completed to assess the best and worst performing flats within the block and therefore determine the over all efficiency of the scheme as a whole. A 3 bedroom maisonette on the top corner of the building as the least efficient (4 faces fully exposed) and a 2 bedroom flat on the interior of the building (3 faces fully exposed) will be calculated.

Flat Types 3 Bedroom family Maisonettes 2 Bedroom Couple/Single flats 4 Bedroom Large family flats Commercial units 1. Entrance hall 2. Living room 3. Kitchen 4. Bathroom 5. Bedroom 6. Study 7. Dining room 8. Landing 9. Storage/Utility 10. Multi purpose

Key:

Maisonettes Entry floor

1st Floor

4.

3.

4.

1.

5.

8.

10.

The site is in the centre of Glasgow’s Merchant City area and is part of a larger master plan for the area. The site has good southern light exposure so the building is orientated to take advantage of this. However being so close to Trongate and Argyll Street localised pollution is an issue. Sound pollution from the busy streets is another factor that needs considered due to the specific area being near the centre of the city.

5.

7.

2.

5.

Couple/Single flats

Wilso

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5.

5.

4.

1.

9.

3.

2.

Large family flat

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7.

5.

5.

4.

1.

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6.

9.

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5.

2.

3.

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Couple/Single flat Fresh air rate is calculated by: Each person requires 8L of air per second.

Ventilation Heat Loss:

Volume = 192 m3 Number of inhabitants = 5 people Fresh Air Rate = 0.04m3/s Sp.ht : 0.34 ACH: 0.5

5 x 8 =40L/s Convert into m3 40/1000 =0.04m3/s

Q= ACH x Volume x Sp.ht x dt dt = The difference between indoor and outdoor temperature.

Sp.ht : Specific heat factor of air.

Calculated by:

Assuming indoor temperature is held at 21° the average monthly temperature difference is:

(Specific heat capacity of air x 1000 (converting kJ to J) x density of air) /(3600 to convert to seconds)

Jan Feb Mar Apr May Jun July Aug Sep Oct Nov Dec

dt

Q(W)per hr

hrs/mnth

Ventilation loss =

17.30 17.00 16.50 14.40 10.50 7.90 5.90 6.30 8.80 11.70 15.20 16.90

564.67 538.56 538.56 470.02 342.72 257.86 192.58 205.63 287.23 381.89 496.13 551.62

744.00 696.00 744.00 720.00 744.00 720.00 744.00 720.00 744.00 720.00 744.00 720.00

420.12 374.84 400.69 338.41 254.98 185.66 143.28 148.06 213.70 274.96 369.12 397.16

(1.01 x 1000 x 1.2) / (3600) = 0.34 ACH: Air changes per hour.

Figures taken from CIBSE Guide A

(Q x number of hours in the month) /1000

Fabric Heat Loss: Wall and Window surface areas (m2) North wall North window East wall East window South wall South window West wall West window

12.20 7.00 25.00 7.00 9.45 9.75 21.50 10.50

Intermediate Floor detail 1:20

U Value Calculations:

Walls Material Internal Clay board Vapour barrier Hemp insulation Wood fibre insulation Breather membrane External

Thickness (m) Thermal conductivity (W/mK) Thermal Resistance (m�K/W) 0.00 0.00 0.12 0.03 0.40 0.06 0.00 0.00 0.00 0.40 0.04 10.13 0.03 0.04 0.66 0.00 0.00 0.00 0.00 0.00 0.06 Total 11.03

U value =

0.09 Wm2K

Wall detail 1:20 Glazing U value found at:

Windows Pilkington Double glazing Argon filled

U value =

1.8 Wm K 2

https://www.pilkington.com/~/media/ Pilkington/Site%20Content/UK/Reference/ TableofDefaultUValues.ashx In line with Part L Government Building Regulations.

Roof Material

Thickness (m)

Thermal conductivity (WmK)

Thermal resistance (m2K/W)

0.00 0.25 0.14 0.15 0.10 0.10 0.15 0.00

0.00 0.04 0.04 0.02 0.33 0.70 0.15 0.00

0.12 6.41 3.68 6.25 0.30 0.14 1.00 0.06 17.97

Internal Clayboard Wood fibre insulation Waterproof insulation Drainage layer Gravel Soil External

Total

U value =

0.06

Area weighted Values: Average U value for each face = (A Wall x U Wall ) + (A Window x U Window) ____________________________ (A Wall + A Window) Face

Average U value

North face East face South face West face

0.71 n/a 0.96 0.65

Parapet/Roof detail 1:20

Specific Heat loss: Area weighted U Value x Total face area Face North East South West

Total Area

Specific Heat loss

19.20 32.00 19.20 32.00

13.71 n/a* 18.41 20.85

Total

* The East face of the flat is not exposed to the outside air. It is within a communal glass courtyard style close area that exists between the flats and therefore making fabric losses from this face negligible.

East face

52.96W

Convert into kWh: (Total specific heat loss x number of seconds in an hour) / 1000 Fabric Heat Loss =

190.67 kWh

Total Monthly Heat Loss Ventilation Heat loss + Fabric heat loss Month

kWh

January 610.78

February 565.50

March 400.69

April 529.08

May 445.65

June 185.66

July 143.28

August 148.06

September 213.70

October 465.62

November 369.12

December 397.16

Rendered section through communal glass Close.

Solar Heat Gains

SHG = g value x solar irradience x area of glazing

G value 0.45

Area SHG/day (kW) Monthly Annually

January 31 days Irradience kWh/m^2 0.57

East Area 7.00 1.80 55.66 655.36 South Area 9.75 2.50 77.53 912.82 West Area 10.50 2.69 83.49 983.04

TOTAL 216.68

February 28 days Irradience kWh/m^2 1.27

East Area 7.00 4.00 112.01 1460.18 South Area 9.75 5.57 156.02 2033.83 West Area 10.50 6.00 168.02 2190.27

TOTAL

436.05

TOTAL

2609.93 3635.26 3914.90

862.91

30 days Irradience kWh/m^2 3.65

East Area 7.00 11.50 344.93 South Area 9.75 16.01 480.43 West Area 10.50 17.25 517.39

4196.59 5845.25 6294.88

5737.25 7991.17 8605.88

5886.72 8199.36 8830.08

July

31 days Irradience kWh/m^2 4.72

East Area 7.00 14.87 460.91 South Area 9.75 20.71 641.98 West Area 10.50 22.30 691.36

5426.82 7558.79 8140.23

TOTAL 1794.25

August 31 days

TOTAL 1000.62

October 31 days

Irradience kWh/m^2 1.46

East Area 7.00 4.60 142.57 1678.64 South Area 9.75 6.41 198.58 2338.10 West Area 10.50 6.90 213.85 2517.95 TOTAL 555.00

November 31 days Irradience kWh/m^2 0.72

East Area 7.00 2.27 70.31 827.82 South Area 9.75 3.16 97.93 1153.04 West Area 10.50 3.40 105.46 1241.73 TOTAL 273.70

Irradience kWh/m^2 0.38

East Area 7.00 1.20 37.11 436.91 South Area 9.75 1.67 51.68 608.55 West Area 10.50 1.80 55.66 655.36

May

TOTAL 1896.89 June 30 days Irradience kWh/m^2 5.12

East Area 7.00 16.13 483.84 South Area 9.75 22.46 673.92 West Area 10.50 24.19 725.76

TOTAL 883.52

December 31 days

TOTAL 1342.74

31 days Irradience kWh/m^2 4.99

East Area 7.00 15.72 487.27 South Area 9.75 21.89 678.70 West Area 10.50 23.58 730.91

Irradience kWh/m^2 2.72

East Area 7.00 8.57 257.04 3127.32 South Area 9.75 11.93 358.02 4355.91 West Area 10.50 12.85 385.56 4690.98

April

TOTAL 1524.35

September 30 days

March

31 days Irradience kWh/m^2 2.27

East Area 7.00 7.15 221.67 South Area 9.75 9.96 308.75 West Area 10.50 10.73 332.50

Irradience kWh/m^2 4.01

East Area 7.00 12.63 391.58 4610.50 South Area 9.75 17.59 545.41 6421.76 West Area 10.50 18.95 587.36 6915.75

TOTAL 144.45

Casual Gains

Number of occupants Heat gain per occupant (W) 110.00 Hours spent in flat Daily Monthly Yearly

Lighting W/m^2 Ground Area m^2 Time Lights On (h) Daily (kWh) Monthly Yearly

Appliances Laptop (W) Time on Laptop (h) Amount of Laptops Daily (kWh) Monthly Yearly

Fridge (W) Time On (h) Daily (kWh)

3.00 16.00 5.28 158.40 1927.20

6.00 60.00 6.00 2.16 32.16 367.16

80.00 12.00 2.00 1.92 57.60 700.80

Monthly 108.00 Yearly 1314.00

Cooker (W) 1000.00 Time on (h) 1.00 Daily (kWh) 1.00 Monthly 30.00 Yearly 365.00

Washing Machine (W) 1200.00 Time on per month (h) 6.00 Monthly 7.20 Yearly 86.40

Tumble Dryer (W) 2700.00 Time on per month (h) 3.00 Monthly 8.10 Yearly 97.20

Total Appliances annually kW 4857.76 Total Appliances monthly kW

401.46

150.00 24.00 3.60

Conclusion

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

Ventilation loss Fabric loss Solar gain Casual gain Total loss Total gain 143.28 148.06 213.70 274.96 369.12 397.16 420.12 374.84 400.69 338.41 254.98 185.66

190.67 190.67

190.67 190.67 190.67 190.67 190.67 190.67 190.67 190.67 190.67 190.67

1794.25 1524.35 1000.62 555.00 273.70 144.45 216.68 436.05 862.91 1342.74 1896.89 1883.52

401.46 401.46 401.46 401.46 401.46 401.46 401.46 401.46 401.46 401.46 401.46 401.46

333.94 338.72 404.37 465.62 559.78 587.83 610.78 565.50 591.35 529.08 445.65 376.32

2195.71 1925.81 1402.08 956.46 675.16 545.91 618.14 837.51 1264.37 1744.20 2298.35 2284.98

The months are ordered to reflect the heating season more accurately for comparison.

Heating Season (kWh/Month) 2000.00 1800.00 1600.00 1400.00 1200.00 1000.00 800.00 600.00 400.00 200.00 0.00

Ventilation loss

Fabric loss

Solar gain

Heating Season (kWh/Month)

2500.00 2000.00 1500.00

Casual gain

In conclusion, the 2 bedroom Couple/ Single flat requires 5.5 weeks heating annually.

1000.00 500.00 0.00

Total loss

Total gain

Water heating Demand Table taken from the energy saving trust government guidelines. kW to heat 100L with electric immerser =3.5kW Maximum Cost per kW= 17p Number of inhabitants = 3

https://www.gov.uk/ government/uploads/ system/uploads/ attachment_data/ file/48188/3147-measuredomestic-hot-waterconsump.pdf

Total water requirement = 150L kW to heat water per day = 5.25kW Cost to heat water per day = ÂŁ0.89 Cost monthly = ÂŁ26.77

Space heating/Water heating comparison (kW) 1000.00 900.00 800.00 700.00 600.00 500.00 400.00 300.00 200.00 100.00 0.00

Average Space heating

Water heating

This graph shows that the water heating compared with the space heating demand on average over the course of a month. The water heating demand is small enough in comparison to justify the use of an electric immerser water heater.

Maisonette Ventilation Heat Loss Δt = 21°- Outdoor temp Jan Feb Mar Apr May Jun July Aug Sep Oct Nov Dec

17.30 17.00 16.50 14.40 10.50 7.90 5.90 6.30 8.80 11.70 15.20 16.90

hrs/mnth 744.00 696.00 744.00 720.00 744.00 720.00 744.00 720.00 744.00 720.00 744.00 720.00

Q(W)

1129.344 1109.76 1077.12 940.032 685.44 515.712 385.152 411.264 574.464 763.776 992.256 1103.232

Total kW 840.23 772.39 801.37 676.82 509.96 371.31 286.55 296.11 427.40 549.91 738.23 794.32

Fabric Heat Loss

North wall North window East wall East window South wall South window West wall West window Roof

Area m2 24.4 14 50 14 18.5 19.5 50 14 60

Area weighted values North face 0.71 East face 0.46 South face 0.97 West face n/a Roof 0.06

Specific Heat Loss U value * Area Total Area North 38.40 East 64.00 South 38.40 West 64.00 Roof 60.00

Total W

Convert to kWh

Specific Heat Loss 27.41 29.73 37.16 n/a 3.34 97.65 351.54

Monthly Heat Loss

January

February

March

April

May

June

July

August

September

1191.77 1123.93 801.38 1028.36 861.51 722.85 638.09 296.11 778.94

October

November

December

901.46 1089.78 1145.87

Casual Gains Number of occupants Heat gain per occupant (W) Hours spent in flat Daily Monthly Yearly

Lighting W/m^2 Ground Area m^2 Time Lights On (h) Daily (kWh) Monthly Yearly

Appliances Laptop (W) Time on Laptop (h) Amount of Laptops Daily (kWh) Monthly Yearly

5 110.00 16 8.8 264 3212 6.00 120 6 4.32 129.6 1576.8 80.00 12 4 3.84 115.2 1401.6

Fridge (W) 150.00 Time On (h) 24 Daily (kWh) 3.6 Monthly 108 Yearly 1314

Cooker (W) 1000.00 Time on (h) 2 Daily (kWh) 2 Monthly 60 Yearly 730

Washing Machine (W) 1200.00 Time on per month (h) 10 Monthly 12 Yearly 144

Tumble Dryer (W) 2700.00 Time on per month (h) 5 Monthly 13.5 Yearly 162

Total Appliances monthly kW 702.3 Total Appliances annually kW

Solar Heat Gains

8540.4

SHG = g value x solar irradience x area of glazing

TOTAL 3283.20

G value 0.45 July

East Area 29.74 921.82 10853.64 January SHG/day Monthly Annually South Area 41.42 1283.96 15117.57

West Area 29.74 921.82 10853.64

East Area 3.59 111.32 1310.72

TOTAL 3127.59 South Area 5.00 155.05 1825.64 West Area 3.59 111.32 1310.72 August

TOTAL 377.70 East Area 25.26 783.15 9221.00 South Area 35.19 1090.82 12843.53 February West Area 25.26 783.15 9221.00

East Area 8.00 24.03 2920.37

TOTAL 2657.13 South Area 11.14 312.04 4067.65 West Area 8.00 224.03 2920.37 September

TOTAL 760.10 East Area 17.14 514.08 6254.64 South Area 23.87 716.04 8711.82 March West Area 17.14 514.08 6254.64

East Area 14.30 443.33 5219.87

TOTAL 1744.20 South Area 19.92 617.50 7270.53 West Area 14.30 443.33 5219.87 October

TOTAL 1504.16 East Area 9.20 285.14 3357.27 South Area 12.81 397.16 4676.20 April West Area 9.20 285.14 3357.27

East Area 23.00 689.85 8393.18

TOTAL 967.43 South Area 32.03 960.86 11690.49 West Area 23.00 689.85 8393.18 November

TOTAL 2340.56 East Area 4.54 140.62 1655.64 South Area 6.32 195.86 2306.07 May West Area 4.54 140.62 1655.64

East Area 31.44 974.55 11474.51

TOTAL 477.09 South Area 43.79 1357.40 15982.35 December West Area 31.44 974.55 11474.51

East Area 2.39 74.21 873.81

TOTAL 3306.50 South Area 3.33 103.37 1217.09 June 2.39 74.21 873.81 West Area East Area 32.26 967.68 11773.44

TOTAL 251.80 South Area 44.93 1347.84 16398.72 West Area 32.26 967.68 11773.44

In Conclusion Ventilation loss Fabric loss

July 286.55 August 296.11 September 427.40 October 549.92 November 738.24 December 794.33 January 840.23 February 772.39 March 801.38 April 676.82 May 509.97 June 371.31

Solar gain Casual gain Total loss

351.54 351.54 351.54 351.54 351.54 351.54 351.54 351.54 351.54 351.54 351.54 351.54

3127.59 2657.13 1744.20 967.43 477.09 251.80 377.70 760.10 1504.16 2340.56 3306.50 3283.20

702.30 702.30 702.30 702.30 702.30 702.30 702.30 702.30 702.30 702.30 702.30 702.30

638.09 647.65 778.94 901.46 1089.78 1145.87 1191.77 1123.93 1152.92 1028.36 861.51 722.85

Total gain 3829.89 3359.43 2446.50 1669.73 1179.39 954.10 1080.00 1462.40 2206.46 3042.86 4008.80 3985.50

Heating Season (kWh/Month) 3500.00 3000.00 2500.00 2000.00 1500.00 1000.00 500.00 0.00

Ventilation loss

Fabric loss

Solar gain

Casual gain

Heating Season (kWh/Month) 4500.00 4000.00 3500.00

In conclusion, the 3 bedroom Maisonette flat requires 7 weeks of heating annually.

3000.00 2500.00 2000.00 1500.00 1000.00 500.00 0.00

Total loss

Total gain

Space heating/Water heating comparison 1600.00 1400.00

kW to heat 100L =3.5kW Cost per kW= 17p Number of inhabitants = 5

1200.00 1000.00

Total water requirement = 200L kW to heat water per day = 7kW Cost to heat water per day = ÂŁ1.19

800.00 600.00 400.00

Cost monthly = ÂŁ35.70

200.00 0.00

Water Heating Demand

Average Space heating

Water heating

Costing and Bills Considering the Scottish government target of 100% renewable electricity by 2020. The most responsible, low environmental impact source of heating and cooling in this case would be electricity.

Especially when in an inner city with existing infrastructure where the environmental impact of transporting wood chip for biomass would undo its low carbon qualities. Gas is inappropriate as it is a finite fossil fuel.

Taken from the Scottish government guidelines. http://www.gov.scot/Topics/BusinessIndustry/Energy/Facts

Taken from The Energy Saving Trust http://www.energysavingtrust.org.uk/aboutus/our-calculations

Although electricity could be considered one of the most expensive options for heating and cooling in Scotland is can be considered one of the most renewable. The building has been designed in such a way that heating and cooling requirements are minimal therefore reducing cost.

The building is heated by a community air source heat pump working from the plant room on the ground floor at the back of the commercial units to reduce noise pollution into the homes.

The heat pump is used to heat radiators in each of the flats.

Couple/Single flat

Maisonette

Annual heating demand = 10939.74 kWh

Annual heating demand = 17941.93 kWh

Heat pump COP: 4.3 kWh electrical input required = 2544.12 kWh

kWh electrical input required = 4172.54 kWh

Cost per kWh = 13p Annual cost of heating =

Annual cost of heating = ÂŁ330.74

ÂŁ542.43

Heat pump coefficient of performance taken from: http://www.greenmatch.co.uk/ blog/2014/08/the-running-costs-of-heatpumps

Air source heat pump The air source heat pump plant room is placed on the ground floor on the north side of the building, at the back of the commercial units. This keeps it separate from the residential accommodation to prevent issues with noise pollution. The plant room will be lagged with sound insulation to further reduce the noise. The fans for the heat pump will have access to the outside air via vents along the north wall.

The pipes will reach the flats via the three service columns located at the north side of the building.

The Air source heat pump is suitable because of the Scottish climate having rare extreme fluctuations in temperature which increases its efficiency.

The heat pump will be used to heat radiators in the flats. The pipe trail in the service void in the floor would look like this with the red boxes representing radiators mounted on the walls.

Couple/Single flat

Maisonette Entry and 1st floor

Ventilation Both flats use natural cross ventilation with vents at the north and south faces. Vents are also positioned to allow air to pass into the communal glass break out space which is also naturally ventilated from the north and south faces. This reduces drafts and makes use of excess heat.

Ventilating into the break out space or to the open air outside provides the inhabitants with more options and control over their environment. There are also operable windows on the north and south of each flat for further ventilation in the summer months. However with the city air, the pollution has to be considered.

The green planter in front of the window will provide some shielding from this pollution from the south improving air quality. Air coming through the vents will be filtered. Air moving through the break out space will also be filtered from the south.

Couple/Single flat

Vents in back of openable window in break out space

Vents in back windows

Solar radiation on the south face of the building will encourage natural ventilation toward the cooler northern vents of the building.

Cross ventilation of the break out space.

Mechanical extract vent manually operated for bathroom through the wall.

Ventilating into break out space

Vents and openable glass louvers at the front of break out space

Vents and openable window at the front of the flat.

Kitchen window for extra ventilation as well as extract hood above cooker.

Windows for manual ventilation of kitchen and bathroom.

Maisonette

Entry Floor

Warm southern exposure encouraging natural ventilation to the cooler north

Vents into the break out space.

Vents in south windows Vents in north windows

1st Floor

Vents into the break out space.

Vents in south windows

Day lighting, Shading and Solar radiation The building is orientated to the south with a large glass exposure making maximum use of natural sun light. It is shaded by its deep facade and green buffer to prevent over heating. The dark red masonry will also help absorb the solar radiation. There are windows to three sides of each flat maximising natural light from the south, diffuse light through windows on to the glass enveloped break out space and ambient light from the north.

As demonstrated the deep facade helps control direct sun light and therefore limits excess solar radiation improving thermal comfort and the control the inhabitants have over their environment.

All artificial lights specified will be full spectrum LEDs due to their improved quality and comfort on older LEDs, and their life span and energy efficiency.

Low Carbon Strategy To reduce the carbon foot print of the building integrated plant life has been incorporated into the design early on. With a green roof to harvest rain water and window planters to help counter the effects of pollution, the design aims to improve the environment as well as be aesthetically pleasing. The window planters will be populated with diverse native species of perennials as well as small shrubs to try and support the local ecosystem, particularly bees.

The heating system is electric based due to the Scottish governments target to be 100% renewable by 2020 therefore reducing the carbon released to power the building. It also uses a heat pump further increasing energy efficiency.

The use of natural ventilation and solar shading to help avoid over heating and other passive energy saving strategy was put in place to help reduce the CO2 emissions and alleviate the need for mechanical solutions.

Renewable Energy The use of a heat pump to improve energy efficiency was the most logical renewable energy strategy for this inner city housing scheme due to its location and the renewable targets set for electrical energy by the Scottish government.

Solar panels seemed wasteful due to the poor quality of sunlight we receive in Scotland but were considered earlier on in the project.

Materials All materials and finished specified such as hemp and wood fibre insulation were picked due to their renewable and responsible sources and their clean, non toxic qualities to improve the over all heath and air quality of the inhabitants. There have been no known toxic or off gasing materials used in the construction of this building.

The steel frame may have a high embodied energy but is more easily recycled than concrete at the end of the buildings life cycle along with the masonry and glazing.

Design changes made to improve calculations When calculating the performance of the building initially I discovered I had a problem with extreme over heating due to the very large southern exposure. I then reduced the window size and deepened the facade as well as adding windows to other sides of the building to take advantage of non direct sun light.

I experimented with solar panels for water heating but realised they weren’t cost effective or efficient enough for the water heating demand I had to design for.

I improved the insulation within the walls to gain better u values and therefore improve fabric losses of the building.

Working out the most efficient way to space heat was one of the biggest challenges for me in this project due to the city site and the varying demands every time I improved the fabric losses. Settling of a heat pump took much deliberation as I am aware that they have optimum conditions and require electricity which is not yet fully renewable. Also the placement of the heat pump was difficult. I was between putting it down in the plant room or having individual setup for each apartment using the air in the break out spaces. I decided this was inappropriate due to the noise and cost of setup. It seemed wasteful to have so many small units rather than a large communal one as well as less aesthetically pleasing. The communal one is more cost effective.

I set out on this project with the intention of using biomass but after some research I concluded that it was futile due to the amount of energy required to bring the wood pellets/chips into the city, undoing its low carbon effects.