You heat your home with electric heat you wish to reduce your electric bills so
you have decided to burn wood in wood furnace. What are the advantages & disadvantages of doing this? What other steps could you take to conserve energy?
Answers
Explanation:
The challenge to analyzing the cost of wood heat is that cordwood is sold by the cord (that's 132 cubic feet of stacked wood), pellets are sold by the bag or the ton, natural gas is sold by the therm, and fuel oil by the gallon. And let's not forget electricity, which is sold by the kilowatt-hour (KWH).
If you want to make sense of all those confusing units, you need to convert it all to a common measure: the cost per gigajoule (GJ) of useful heat (a gigajoule is about the same as a million BTUs). To do that, you need to take into account how many giga-joules of heat there are in a cord, ton, gallon, or KWH of fuel, and also factor in the efficiency of the stove, boiler, or heater you are using. When you work that all in, you can get a true picture of how much you can save by switching from one heating fuel to another.
Explanation:
Combustion efficiency represents a calculated measurement (in percent) of how well the wood burning device is converting the wood into useable heat. It does not reflect how much of the useable heat produced is transferred to the home.
Overall efficiency is the percentage of heat that is transferred to the space to be heated when a load of fuel (e.g., firewood, pellets) is burned. Actual efficiency will vary depending on factors such as wood moisture, appliance operation and installation (e.g., outside piping, chimney height).
Overall efficiency is a better measure than combustion efficiency of the amount of heat that is delivered to the home. Often advertisements will list combustion rather than overall efficiency since it is the higher of the two calculated efficiencies for any given device. For example, an advertisement on a website or brochure may say “85% efficient” and although not specified, it is the combustion efficiency. The overall efficiency may be 10 % to 20% lower. If you encounter an unspecified efficiency, you can check to see if the overall efficiency number for the specific device is included on EPA’s certified wood stove database. If not, you may want to contact the manufacturer or ask your retailer to provide you with documentation of overall efficiency.