Presentation on theme: "Doing without and more with less"— Presentation transcript:
1 Doing without and more with less ConservationDoing without and more with less
2 Outline Energy conservation Principles Space heating Lighting RecyclingTransportationIndustry
3 Why conservation?Electricity Conservation saves 3 X as much fuel as the energy you don’t use.Therefore, a 3-fold reduction in pollutionSaves moneyDeprivation: Dealing with less.Efficiency: Doing more with less
4 Home heatingThe 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 lossesThe rate of heat loss (power loss) is proportional to the temperature difference and the surface area.Qloss/t = k A TMaterial of heatconductivity, kAreaT outsideT insideQ loss
6 Reducing heat lossesHeat loss is proportional to temperature difference.Q1 / Q2 = T1 / T2Q1/Q2 = (67-35)/(75-35) = 32/40 = 80%A 20% savings.T in = 75 FT out = 35 FORT in = 67 F
7 The law of heat conduction Q loss / t = A T / RR 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 = 1Q 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 = 2.06Fiberglass: R = 11.0Gypsum siding: R = .45R total = 14.36Air layersFiberglassGypsum sidingInsulatingSheathing
9 Heating needsHDD = The length of the heating season, in days, times the average temperature differenceHDD = 150 days (65 F – 35 F) = 4,500Macomb has 6000 HDDHeating need per season:Qtotal = HDD (Area)(24 hrs/day) RAn 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.