Search Our Site


Virtual Tour

Candle Sooting Print E-mail



Upon inspection, the furnaces have been found to be operating correctly and doing what they are supposed to do: pull air into the return, condition the air, then return the conditioned air to the living space. Of course, anything in the air will be pulled in and redistributed through the duct system. The problem is actually "candle wicking", sometimes also referred to as "ghosting".

Investigations have shown that soot produced by scented candles, jar candles and oil candles are the likely cause of these black stains. In the last 5 years the candle industry has doubled as demand has increased. Candles are now mass produced, using what is suspected to be lower grade candle waxes and material that result in a higher oil content. These candles produce ore soot when burned.

In a test by Engineer Ron Baily in Palm Beach Gardens, Florida, four candles were burnt for a total of 15 hours. These candles produced so much soot in the home that the testers were forced to stop for fear of creating too much damage in the house. "We had signigican soot production on the walls, drapes, dishwasher, refrigerator, and the AC filter."

Bailey explained that there are two issues to consider when looking at how a candle might soot. "The length, thickness, and strength of the wick highly influence how a candle burns, and also what is in the candle wax itself." Today the growing trend si in the use of aromatic candles. Fragrance added to the wax should be specifically for use in candles. The high temperatures can cause chemicals to behave differently once burned. "Five percent paraffin wax is good," said Bailey. "But with many of the candles in stores today, we find a mixture of materials, including some fragrances that were not intended for this use." The mixture of the various fragrances and chemicals can result in a candle that is going to burn dirtier than expected.

Most filters used in furnaces are not capable of removing the ultra fine soot produced by candles. When confronted with a claim of a furnace suspected of causing sooting in the home, check first for the use of candles in the home.