We rate cars in MPG Miles per Gallon. Knowing your cars MPG and the current cost of fuel you can calculate how much it will cost in fuel for each mile you drive. Most of us don’t bother to calculate the cost per mile but we do understand that the higher the MPG the better, because it will cost less to operate.
However with furnaces, heat pump, electric heat, etc… The rating is in AFUE, SEER, EER, HSPF, etc… But what does that mean in dollars and cents to heat my home? What if I am using a heat pump or a gas furnace, which is cheaper? The chart above should help you understand what it means.
This chart is assuming an across the board comparison of 1 Million BTU’s of heat output, the usable heat produced by various types of heating equipment. The definition of BTU is British Thermal Unit. For your information 1 BTU is the equivalent of the heat produced by burning 1 wooden kitchen match.
Now let’s look at the different types of heating systems used.
Electric Resistance Heat used by Electric furnaces, water heaters, dryers, hair dryers; Incandescent Light Bulbs and toasters are examples of resistance heat. A Watt of energy flowing through a resistance load equals 3.412 BTU’s. The electric company charges us by the Kilowatt or 1,000 watts of electricity used.
Natural Gas produces 1,000 BTU’s per cubic foot. The gas company charges us for each 100 cubic feet of gas used.
Liquefied Petroleum Gas produces 95,500 Btu’s per gallon. The Propane Company charges us by the gallon.
Wood Pellets produce about 7,800 Btu's per pound or 312,000 Btu's per 40# bag.
Corn produces about 314,000 Btu's per bushel.
AFUE stands for Annual Fuel Usage Efficiency. OK what does that mean? Simply put an 80% AFUE gas furnace Natural or L.P. will produce .80 cents worth of heat for every dollar you spend, and .20 cents of your dollar goes out the flue to the birds. Imagine driving to the gas station and buying $5.00 worth of gas, pumping $4.00 in your cars tank and $1.00 on the ground! Sounds ridiculous doesn’t it? The lowest furnace allowable by law is 78.5% AFUE. Most gas water heaters are about 70% AFUE.
Heat Pumps are 200%-450% efficient which means that they will produce $2.00-$4.50 for every dollar you spend on electricity. To Learn more about heat pumps check out (future page).
This chart is using the actual cost of Natural gas and electric energy used in My home for the month of January 2010. January 2010 was a very cold month in North West Missouri, with lots of snow, sub-zero temperatures and over 2 weeks with out any sunshine. It was the coldest month in our area in several decades. Both the Natural gas and the electrical included service fees and taxes and this chart reflects these costs. I have an 80% gas furnace and a 70% gas water heater and that is all I use natural gas for. I don't personaly use L.P. Gas but, I used the going cost per gallon in this chart. The yellow highlighted areas represent my energy costs.
Check out www.onlineconversion.com where we obtained some of our information.