Black Film on Interior

I performed an inspection on a home that was built in 1999 and was in very good shape and well maintained. I found very little to report on this home and was stumped in regards to the black almost oily film on the interior walls, ceilings, fixtures, vents and edges of the carpet. Upon discussion with the owners, the Mrs. claimed that she has been diagnosed with “Chronic fatigue Syndrome”…whatever that is. I have not a clue what may cause something like that and I explained to them that the indoor air quality should be further tested to try to determine if indeed there were anything that is in the indoor air that may be harmful to her well being. I am not a Industrial Hygienist and I acknowledged that I am only certified to test for mold, wether it is visible or airborne. Anyhow, film was not in the garage and I was saying to myself that it must be coming from the forced air furnace…upon a diligent inspection I could not determine anything that might be coming from the furnace. Maintenance was done annually and the blower had been replaced within the past year. I really don’t know what this could be and I feel badly for the Mrs. and would really like to help her…but, I am not sure how. I did take some air samples upon their request and I will get the results back tomorrow. Any feedback or insight would be greatly appreciated. The photos are darker than I would have liked, however, that is because she had all the windows completely covered and it was a clear and beautiful day in Michigan.




this type of “ghosting” could be from excessive candle use

Oil furnace ever have a ‘puffback’?

seen something like this once. the owners smoked so much and never opened windows. it was so bad you could see on the outside of the building where the windows and walls had air leaks, there would be a greasy film streak on the outside. “Chronic fatigue Syndrome” related to an under active or over active(cant remember which it is) thyroid gland known to be caused by trauma, sever stress and heavy smoking could cause it as well

You get the same symptoms when you use kerosene heaters or the oil furnace needs it’s filters cleaned or burners adjusted…

This was a 90% efficient gas direct vent furnace that was functional and maintained. The buyers did smoke, but they claimed to smoke only in the garage, which there was a “smoking station” set up in there. I was skeptical about this and since I don’t smoke I figured I could smell remnants of the smoke inside the home. I even smelled some clothing in their closets as I was doing the inspection and no significant signs of smoke.


Thanks for your input and replies so far!:slight_smile:

My first reaction to your description and pictures is a pinhole in the heat exchanger of a hot air furnace. I’ve seen that situation with a hole so small it wasn’t very noticable unless you had a really sensitive nose.

Did you use a CO tester on an the operating furmace?

How long has this porblem been around? Just like a HI the furnace could have developed hole after being examined (and that assumes it was properly examined)

Whatever it turns out to be my money is on some combustion source (incompelte combustion casuing soot)

Candles…seen it many times. Smoking usually has a yellow-brownish staining.