Appliance Analysis Findings - Newsletter

January 2008

Home Fire - Is the Furnace to Blame?

There was a fire in a two-story home. It looked as if the fire started in the supply air metal ducting, away feet away from the furnace. The insurance company knew that if a gas furnace has "incomplete combustion" one byproduct can be methane gas. Methane gas is combustible.

So they needed to know - was the furnace the cause of the fire? They called Appliance Analysis, who were able to find an answer.

Read the case study to learn what happened or visit our video library to see what happened.

What is Incomplete Combustion?

Combustion produces heat and sometimes light due to a chemical reaction between a fuel (usually a hydrocarbon) and an oxidant. Complete combustion uses up all the fuel in a reaction and produces a limited number of products in the reaction. Incomplete combustion occurs when there is not enough of an oxidant to burn up all the fuel in an efficient manner.

In incomplete combustion, the reaction is inefficient and produces not only the products that would be created in complete combustion but other products as well. When a hydrocarbon burns in air, the reaction will yield carbon dioxide, water, carbon monoxide, pure carbon (soot or ash) and various other compounds such as nitrogen oxides.

Furnace Tips

To extend the safe life of your furnace, consider the following.

• Change or clean filters monthly. To determine how dirty the filters are, hold them up. If you can easily see light through them, then they're still clean enough to use.
• Inspect the furnace for worn, shiny and sagging belts. They cause undue stress on the fan motor.

Feel free to share these tips with your clients.