1. The Igloo A Dome of Many Wonders

2. Outline Igloo basics Igloo science Construction of an igloo An igloo in Hyde Park

3. What is an igloo? Comes from Inuit word for house Usually means a dome-shaped dwelling made of snow Not a quinzhee

4. Igloo Culture Igloos were built by Inuit in the Canadian central arctic and Greenland’s west shore Used mainly as temporary shelter on hunting trips Larger semi-permanent igloos were also built that could house several families Design of igloos varies between Inuit cultures

5. Igloo Physics A hemisphere is not a good dome shape Ideal dome shape is a catenary – Innuit design is very close to this ideal Height/Diameter = 0.3 for minimal stress But compression  shrinking so it’s best to make H/D > 0.3 Theoretical maximum size of igloo is: D = 34 ft., H = 12 ft.

7. Igloo Physics A hemisphere is not a good dome shape Ideal dome shape is a catenary – Innuit design is very close to this ideal Height/Diameter = 0.3 for minimal stress at base But compression  shrinking so it’s best to make H/D > 0.3 Theoretical maximum size of igloo is: D = 34 ft., H = 12 ft.

9. More Igloo Physics Rate of heat flow through igloo given by where Q/t = heat flow per unit time, k = thermal conductivity, A = area of interior/exterior of igloo, T i = interior temperature, T o = exterior temperature, L = thickness of igloo Can calculate Q/t in the interior making simple assumptions about people Using reasonable values, temperature difference between inside and outside can be about 60 C

10. Construction of an Igloo Snow must be packed Cut wedge shaped snow blocks using snow saw Lay blocks in helical pattern, cutting block thinner as you go up Dig a trough leading into igloo and cover with snow blocks Terrace interior to so that inhabitants are elevated Cut ventilation holes

11. Block laying pattern

12. Construction of an Igloo Snow must be packed Cut wedge shaped snow blocks using snow saw Lay blocks in helical pattern, cutting block thinner as you go up Dig a trough leading into igloo and cover with snow blocks Terrace interior to so that inhabitants are elevated Cut ventilation holes

13. Igloo Side View

14. Igloos of the Future

15. Building an Igloo in Hyde Park Problem: snow is not well packed –Solution: pack it into buckets Problem: snow is cold and not fun to touch –Solution: buy a shovel Problem: people throwing shit at your igloo –Solution: none

16. The location: 60 th and Drexel

17. Igloo Nick

18. STAGE 1: COMPLETE

21. The Finished Igloo!