1. Environmental house project
Jack Bradley

2. What will be covered in this lecture?
Why people need a house
How technology provides a house
Design skills

3. How many types of house can you name?

4. Traditional Houses
Yurt (2) Igloo
(3) Grass House (4) Pueblo

5. Traditional Houses (5) Tepee (6) Trullo
(7) Forest Pavillion (8) Mandan lodge

6. Traditional Houses
(9) Bedouin tent (10) English Cottage

7. Jack and Joanne have moved again!

8. Reasons for diversity Materials Socio – cultural factors Climate
Ways of Life
Economics
Technology

9. Why people need a house? Physical comfort Domestic activities
Socio – cultural factors

11. What does technology provide?
Materials
Services
Construction

12. Wood – Its properties Resists tensile and compressive forces
Easy to work with simple tools
Light and easy to manipulate
Good thermal insulator
Spans distances
Feels warm

14. Influence of Services Gas Heating Drainage Electricity Hot water
Cold water

15. Design Skills Required
Analysis
Synthesis
Evaluation

16. Keeping Warm
Location
Orientation
Shape

24. Orientation Wind/weather Sun – overheating V natural heat
Topography – drainage, stream use, shelter
Natural shading – trees – summer/winter (deciduous)

25. Green/Sustainable Building Definitions:
To be classed as a green building it is
“…essential for the environmental impact of all its constituent parts and design decisions to be evaluated.”
“ A healthy built environment based on resource efficient and ecological principles.”

26. Design Principles Reduce energy in use
Minimising external pollution and external damage
Design in harmonious relationship with surrounds
Avoid destruction of natural habitats
Re-use rainwater
Treat and recycle waste water
Minimise extraction of materials
Minimise waste materials provided (typically 10%)

27. Green design Solar Collector Rainwater Cistern Conservatory
Earth heat storage bed
Power generation (wind, water etc)
Waste recycling system
Insulation
Renewable materials

31. Example
Sketch a graph of temperature against time for a house where the heating pattern is as follows. The heating is turned on at 6am and off at 11am. It is turned on again at pm and off again at 11pm. When the heating is on, the occupants require the temperature to be 23C. On your graph, indicate the approximate values of the average inside temperature.

33. Heating a house Heat Flow Rate = U-Value * Area temperature difference
Ventilation loss = Specific heat capacity * Mass flow rate of air * Temperature difference
Mass flow rate of air =
Air change rate * House Volume * density of air
3600

34. 0.33 x House Volume x Air change rate x Temperature difference.
Equation
Ventilation Loss =
0.33 x House Volume x Air change rate x Temperature difference.
Average temperature and degree-days
Total heat required = Specific loss * degree days * 86400

35. Example 2
Calculate the rate of heat loss from the house shown below when the temperature difference between the inside and the outside is 20C. The house has an air change rate of 1.0ach, walls with U-values of 0.6Wm-² C-1 and U-values of 0.3Wm-² C-1 for the roof, 0.8 for the floor, 3.4 for doors and 5.6 for the windows. The total area of window is 12m² and there is 4m² of external doors
5.5m 6m 6m

36. Solution 2 Total wall area = 4 x 5.5m x 6m =132m²
Net wall area = total wall area – window area – door area
=132m² - 12m² - 4m² =116m²
Floor area = 6m x 6m = 36m²
Roof area = 6m x 6m = 36m²
House volume = 5.5m x 6m x 6m = 198m²
Fabric loss = U-Value x area x temp. difference
For walls: fabric loss = 0.6 x 116 x 20W = 1392W
For the floor: fabric loss = 0.8 x 36 x 20W = 576W
For the roof: fabric loss = 0.3 x 36 x 20W = 216W
For the windows: fabric loss = 5.6 x 12 x 20W = 1344W
For the doors: fabric loss = 3.4 x 4 x 20W = 272W

37. Total fabric loss = 1392W + 576W + 216W + 1344W + 272W = 3800W
Ventilation loss = 0.33 x house volume x air change rate x temp. difference
= 0.33 x 198 x 1 x 20W = W
Total rate of heat loss = fabric loss + ventilation loss
= 3800W W = W
Specific loss = total rate of heat loss
temperature difference
= W C

38. Internal and Solar gains
In a typical house, the total gains from all sources will be about 1000W.
Te specific loss will approximate to 255W C^-1
Temperature rise from internal & solar gains = Total gains / Specific loss

39. Region
Degree Days
Home Countries
2137
Northumberland
2727
Southeast
2445
North Yorkshire
2534
South
2286
South Yorkshire
2398
Southwest
1966
East Anglia
2468
Severn Valley
2235
West Scotland
2615
West Midlands
2527
East Scotland
2744
Merseyside
2389
North Scotland
2903
Cumbria
2556
Wales
2276

41. Building activity relationship charts