1. Energy and Environment
Energy Conservation
Copyright © 2006 by John Wiley & Sons, Inc.

2. Penny saved is a penny earned
It is better to save a barrel of oil than find a new one.
One side of energy conservation is energy efficiency.
In discussing energy conservation, the main attention will be given to house hold use.
Some more attention will be given to industry and Agriculture

3. Energy Conservation in Industry and Agriculture
The industrial and agriculture sector of the energy economy is so large. However, conservation measures can be divided into some areas which affect all types of activities.
Housekeeping
Waste Heat Recovery and Cogeneration
Process Changes
Recycling
New Developments

4. Energy Conservation in Industry and Agriculture
Housekeeping
Space heating, water heating, and lightining are commonly present in industry.
In comparison with house energy conservation, here the problems are more amenable to solution than in the home because larger units are involved and more technical help is available.

5. Energy Conservation in Industry and Agriculture
Waste Heat Recovery and Cogeneration
Recovered heat energy is often at fairly low temperature but still suitable for space heating, water heating, water preheating, and greenhouses.
In industries there is a trend towards electricity generation on-site because of the recognized value of the heat energy recoverable from the generating facility.

6. Energy Conservation in Industry and Agriculture
Process changes
In many industrial process having large energy inputs, such as uranium enrichment, and refining of chemicals & fuels. In these example of industries there is a possibility to make fundamental changes in the process that will lead to a reduction in energy use per unit of output.
Opportunity to reduce energy use by introducing better technology as it becomes available.

7. Energy Conservation in Industry and Agriculture
Recycling
Recycling is an important steps toward energy conservation and it reduce environmental pollution.
It saves basic resources such as Aluminum, and at the same time reduces the problem of overloaded landfills.
There are numerous examples of successful recycling in industry .
Recycling effective in saving energy, reducing the waste and reducing harmful emission.

8. Space Heating
Ideal house that had perfect thermal insulation, no leackage of air into or out of the house.
Such house no energy would be needed to keep the inside of the house at constant temperature.
Thus such a house is not effective due to the cost and inconvenience of unreasonable amounts of insulation.

9. Space Heating
Above figure shows that two conduction process causing heat loss in a typical house:
1- Thermal conduction
2- Air exchange through the cracks.

10. Space Heating
Thermal Insulation
Thermal insulation will reduce the heat loss by conduction.

11. Space Heating
Degree days: number to measure average outside air temperature. For each day of heating season, the number of degree days accumulated is given by the average temperature difference between inside and outside , inside temperature constant at 650F.
For the entire heating season, the total number of degree days is obtained by summing these degree days for the individual days of the heating season.

12. Space Heating
Ex:
a) Calculate the the number of degree days accumulated in one day which the average outside temperature is 170F
Calculate the number of degree days accumulated during 150 days heating seasonin which the average outside temperature is 170F .

13. Space Heating

14. Space Heating Ex
House with ordinary insulated 2 x 4 with ¾ of insulating sheeting on the outside, fiberglass insulation 3.5 inches thick, and 0.5 gypsum board on the inside. The wall is 20 feet long and 8 feet height. For the following R values , calculate:
The heat loss in Btu for one heating season having 6000 degree days.
Material R
Outside air layer
Insulating sheeting
Fiberglass
Gypsum board
Inside air layer

15. Energy Conservation
There are many steps can be implement to achieve energy conservation including:
1- Lowering of the heaters thermostat to 120oF reduces the losses from and still provides water at a sufficiently high temperature for household use.
2- Insulation may be added to the hot water pipes, and tank for electric water heater.
3- Reduction of the amount of hot water used obviously saves energy.
4- Electronic igniters eliminate the waste of energy due to the pilot light.
5- Flue damper can be installed , this damper must be designed to open whenever the flame comes on.

16. Energy Conservation
water heaters used about 10-20% of the energy consumed in a typical home. Gas and electrical heaters usually been used for water heating.

17. Energy conservation
Energy Efficient Lighting
The electricity used over the lifetime of a single incandescent bulb costs 5 to 10 times the original purchase price of the bulb itself.
Compact Fluorescent Lights (CFL) and Light Emitting Diode (LED) bulbs have revolutionized energy-efficient lighting.

18. The Energy Conserving House
Different studies been conducted to measure the effect of different steps effects on energy consumption.
The large effect was for space heating which is went from 120 million Btu to 35 million Btu a year.
Gas plus electricity also shows other conservation measures taken to reduce the total energy .

19. Public Utilities
Public utilities profit depend directly on how much electricity or natural gas sold to the customers.
For example less energy consumed by customers , the less utility need to be built and better efficiency can achieve.
Niagara Mohawk Power corporation found a number ways to sell the idea of efficiency rather than selling Kilowatt hours of electricity or Btu of Natural gas.

20. Public Utilities
For a typical home, the difference between the annual loss of revenue from a household and the utility cost for the service is ($72/yr lost revenue minus $40/yr cost= 32$/yr). Was charged to the customer every year for eight years.
For the first eight years , each household saves $34/yr for a total saving of $272 over the eight years period. The household realized the benefits from the improvements

21. 1- Find the number of Btu conducted through a wall in 8 hours
1- Find the number of Btu conducted through a wall in 8 hours. The wall is 8 feet high and 24 feet long and has a total R-value of 16.2 hr.0F.ft2/Btu. the inside temperature is 650F and the outside temperature is 160F .
2- A 1500 ft2 wall has an R-value of 11 hr.0F.ft2/Btu. How many Btu are lost through this wall in 5600 degree day heating season?

22. 3- calculate the R-value of brick faced wall that has the following layers: 4 inches of brick, 0.75 inch of insulating sheating, 3.5 inch of urea form, 0.25 inch of plywood. Inside air layer R-value of 0.68 and outside 0.17.
4- A house in Nizwa (6040 degree days) consists of the following:
544 ft2 of a single pare windows
544 ft2 of store walls , 13 inches thick including air layer
480 ft2 store walls, 13 inches thick
1632 ft2 of roof with R-value of 80 including air layers.
Neglecting the heat lost through the concrete slab floor, air filtration and solar energy input. Calculate the total number of Btu needed to heat the home for one heating season.

23. 5- how many Btu would be contributed to the heating of house by the metabolism of four occupants over the six month heating period ? Assume each person generates 100 w and they are in the house 50% of the time .