Energy Conservation
People today are more conscious than ever about the costs of energy, which have risen dramatically since 1973, due to the oil embargo. The prospect of continuing increases in energy costs has made many homeowners and prospective buyers take a very critical look at energy costs. Haphazard, hit-and-miss tactics for conserving energy are not effective in significantly reducing energy costs. While some savings may be realized, many things that can provide great savings are overlooked altogether.
Any energy-related project should be justified by comfort and economic benefit. If the amount of money spent will be returned to you in approximately 7 years or less, that is an improvement that should be considered. If it will take much longer, it is probably not economically beneficial. For example, if an attic does not have any insulation and you know that you can save 60% to 70% of the losses through the attic/ceiling by installing 9 inches to 12 inches of insulation, you should evaluate the cost versus payback.
In a house with a standard fossil fuel heater and a fuel cost of $1000 to heat the house for one year, the losses through the ceiling (assuming that there is no insulation) would be approximately $200 to $250. If it costs $1.20 per square foot (SF) to insulate a 1000 SF attic, the total cost will be $1,200. This will be about a 5 to 6 year payback. If the homeowner insulates the attic, and does a good job, it will cost him about $300 for the insulation. This would yield a payback in less than 2 years.
Insulating the walls is much different. If it costs $1.20 per SF to insulate the walls, plus possibly some cosmetic repairs, and the house has 3,500 SF of wall area, the cost would be approximately $4,200. If the savings are $200 to $250, the payback will be about 20 years. This would not be beneficial. A simplified breakdown of where the $1000.00 fuel cost goes is as follow:
- Approximately 1/3 goes up the chimney to carry moisture and unburned gases and hydrocarbons: $333
- Approximately 1/3 of the remaining goes straight up through the house: $222
- Approximately 1/3 goes through the walls: $222
- Approximately 1/3 is lost to normal entry and exit and at the windows and doors: $222
- There are other considerations, such as air infiltration, relative humidity, and occupants of the property. One adult adds approximately 50 BTUs per hour to the living space.