1. Doing without and more with less
Conservation
Doing without and more with less

2. Outline Energy conservation Principles Space heating Lighting
Recycling
Transportation
Industry

3. Why conservation?
Electricity Conservation saves 3 X as much fuel as the energy you don’t use.
Therefore, a 3-fold reduction in pollution
Saves money
Deprivation: Dealing with less.
Efficiency: Doing more with less

4. Home heating
The goal is to maintain a constant, comfortable temperature.
Therefore, Heat in = Heat out.
Heat out:
Conduction (50-70%)
Convection (up to 30%)
Radiation (5-10%)

5. Conduction losses
The rate of heat loss (power loss) is proportional to the temperature difference and the surface area.
Qloss/t = k A T
Material of heat
conductivity, k
Area
T outside
T inside
Q loss

6. Reducing heat losses
Heat loss is proportional to temperature difference.
Q1 / Q2 = T1 / T2
Q1/Q2 = (67-35)/(75-35) = 32/40 = 80%
A 20% savings.
T in = 75 F
T out = 35 F OR
T in = 67 F

7. The law of heat conduction
Q loss / t = A T / R
R is the R-value, which is a measure of the resistance to heat loss for a given material of given thickness.
i.e. R fiberglass = 3.7 ft2-F-hr/Btu per inch.
The higher R, the lower the heat loss.
Example: A single pane of glass has R = 1
Q loss(glass)/Qloss(fiberglass) = (1/Rglass)/(1/Rfiber) = 3.7 X more loss.

8. An insulated wall Air layers: In: R = .17 R = .68
Insulating Sheathing:
R = 2.06
Fiberglass: R = 11.0
Gypsum siding: R = .45
R total = 14.36
Air layers
Fiber
glass
Gypsum siding
Insulating
Sheathing

9. Heating needs
HDD = The length of the heating season, in days, times the average temperature difference
HDD = 150 days (65 F – 35 F) = 4,500
Macomb has 6000 HDD
Heating need per season:
Qtotal = HDD (Area)(24 hrs/day)  R
An 8 x 20 foot wall with R = in Macomb.
Q total = 6000 (160 ft^2)(24) / = 1.6 x 10^6 Btu/season.
Natural Gas costs 40c per 1 x10^5 Btu, so $6.4 dollars burned to make up loss from that wall.

10. Air infiltration Typical house exchanges air with outside every hour.
Good insulation can reduce that to every 5 hours.
Must have better air-purifying

11. Lighting and Electrical use
Fluorescent bulbs have 10 X longer lifetime, and use 15 W compared to 75W, representing an energy savings of 5 x, and a money savings of 50 x.
Leaking electricity – Most appliances don’t turn fully off. Up to 5% of America’s use of electricity for “standby”mode.