Download presentation

Presentation is loading. Please wait.

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.

Similar presentations

OK

Phy100: Heat transport Three basic forms of thermal heat transport

Phy100: Heat transport Three basic forms of thermal heat transport

© 2018 SlidePlayer.com Inc.

All rights reserved.

By using this website, you agree with our use of **cookies** to functioning of the site. More info in our Privacy Policy and Google Privacy & Terms.

Ads by Google

Ppt on pollution in india free download Ppt on shell scripting interview Ppt on water conservation in hindi Ppt on different sectors of economy for class 10 A ppt on loch ness monster pictures Ppt on do's and don'ts of group discussion clip Ppt on area and perimeter for class 4 Ppt on c++ basic programing Ppt on stock exchange market Ppt on boilers operations coordinator