1. Exam I results P120/2007 Avg: 85.9 = 74.6%

2. Infiltration Q = 0.018 Btu/ft 3.hr.F o V K  T Here K is the number of “Air exchanges per hour” and V is the interior volume of the house/building. Note: some exchange of air is necessary (you need to breath!), and this is not readily apparent in this figure.

3. Some typical R values MaterialThicknessR (ft 2.h. o F/Btu) Hardwood1”0.81 Concrete block8”1.25 1-pane window0.125”0.88 2-pane window0.5” air1.72 Fiberglass7”21.8 Polyurethane1”6.3 Nylon carpet1”2.0 Wood siding0.5”0.81 Plywood0.5”0.627 Plasterboard0.5”0.45 Steel1”0.0032

4. Degree-Days Heating/Cooling http://www.ersys.com/usa/18/1836003/wtr_norm.htm Indianapolis

5. Price of Natural Gas (dollars/MBtu wholesale I believe) http://futures.tradingcharts.com/chart/NG/W

6. “Low-e” (emissivity) coatings on windows Conducting oxide Double metal layer Single metal layer Phys. Today Nov. 2000

7. Heat Pumps

8. Coefficient of Performance As the outside temperature goes down, the performance of a heat pump also goes down. You can, however, design the system to exchange heat with the earth instead of the air (geothermal systems sold locally)!

9. http://eosweb.larc.nasa.gov/EDDOCS/images/Erb/components2.gif

10. Spectrum of Solar radaition at the Earth’s surface H&K fig 6.2

11. Components of solar Energy on Earth H&K fig 6.7

12. Insolation (Btu/ft 2.day) Horizontal surf. surf. at  = latitude Mean monthly T ( o F) H&K Appendix D

13. Fundamental components (any solar energy system) Solar collector Storage system of some sort (to account for night and cloudy days). Energy transfer fluid (which could be air, as in some systems we have seen, antifreeze, or even electrons) Auxilliary/backup system (typically)

14. Fundamental components (any solar energy system) Solar collector Storage system of some sort (to account for night and cloudy days). Energy transfer fluid (which could be air, as in some systems we have seen, antifreeze, or even electrons) Auxilliary/backup system (typically) Q: Does solar energy go to zero on cloudy days?

15. H&K fig 6.8, 6.9 & 6.32 Clear Day Insolation as a function of collector angle Why does the angle make a difference?

16. Typical Passive Domestic solar heating systems H&K 6.26 “Trombe” Wall H&K 6.24

17. Typical Active Domestic solar heating system

18. E.G. Domestic hot-water system

19. Typical collector design (fig 6.18) Can we understand the design criteria for each of these components? What happens if you run such a collector too hot?

20. Focusing collectors (parabolic)

21. National Solar (thermal) test Facility (Sandia New Mexico) http://www.sandia.gov/Renewable_Energy/solarthermal/nsttf.html 5 MW of thermal power for (with 222 “heliostats”) $21M (1978 $’s)