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After this past winter I have noticed a oily black dirt on the walls above the hot water baseboard heating,on electrical outlets&switches,around pictures on the walls,and recessed lighting. I have been told that the boiler has carbon buildup,needs adequate venting in boiler room.I`ve also been told that the attic needs to be cured of all it`s drafts and proper insulation.Can anyone point me in the right direction to the cause of my problem before I repaint and have this happen again? Thanks in advance.
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Repainting is THE LAST thing you should do to "fix" this problem.
The soot you are seeing is usually caused by stuff like candles, oil lamps, etc. It builds up above baseboard heaters due to static charge and/or heated air causes tiny tiny amounts of the soot to condense out on the slightly cooler drywall. It collects around switches and lights due to air leaving the house and the material collects on it's way by.
The rest are all indeed problems, perhaps related perhaps not. This is where a building performance professional would help you. By looking at the whole situation and assesing it.
I can say from a distance that if the attic does need large amounts of air sealing work done, then it will cause the boiler to backdraft. This happens alot in stone houses after they install new windows. Now all the air leaking out the ceilings has to be replaced by pulling air in thru basement windows and sometimes down flue pipes. If it does need air sealing work the holes will be easy to spot, just pull up the batts of insulation on the attic floor and look for the same oily black spots.
More insulation will do nothing unless it is done after the air sealing work. And then only cellulose would help kill any stray air currents missed during the air sealing work. Of course you could just spray the attic floor with PUR foam or icynene and then you install the insulation and the air barrier at the same time. Of course it costs ten times as much, but it's fast!
There may also be mechanical exhaust fans in the house that cause pressure imbalances that make the boiler backdraft. Dryers, bath fans, kitchen fans, range hoods can all combine to depressurize the house sufficiently to cause backdrafting.
As for the condition of the boiler, if it does have large amounts of carbon buildup it is due to either improper flame settings at installation, or the backdrafting is causing a rich condition that leads to sooting.
The boiler room itself may be causing the problem due to other venting appliances fighting for the same air.
Please tell me more information about the house, the type of construction, where you are located, and the boiler room conditions. How many recessed lights do you have? Can you post pictures of the house?
Fred Lugano has a great picture of an atmospheric damper rusted permanently open (backdrafting) on a fuel oil boiler. To remedy the sooting and bad air problems the occupants installed a bath exhaust fan in the boiler room!! Now the sooting was fixed, but the backdrafting was worse. He said the fan was blacker than coal. This house had second floor rooms sheathed with pegboard on the inside!! Talk about leaks!
-Rob
*Had the same symptoms one winter. Turned out to be the boiler needed a tune-up and air balancing. Your mileage may differ. Objects in mirror are closer than they appear.GET A CARBON MONOXIDE DETECTOR! The first time one goes off, you'll think it was worth the $45. For a detector good enough to put in an airplane, see: http://www.avweb.com/articles/codetect/-David
*Chas,It is possible that you were exposed to significant amounts of CO. Chronic exposure to CO can cause very serious long term health effects, and it can be difficult after the fact to establish it was the cause. (Many times, CO poisoning is missed by health professionals, according to the tales of horror on the various CO mail lists and other sources.)Before you have the system serviced, have a full check of the system done: both in terms of CO production (which, since there's carbon soot, there's probably high CO production) AND as to venting: you need to know whether significant CO was getting into the home. If so, you need to find a health professional who knows about CO treatment after the fact.You need to figure out where the "oily black dirt" came from. Rob mentioned the usual candidates, candles, oil lamps (kerosene space heaters produce it big time.) Maybe cooking oils? Do you do a lot of fried food cooking?If none of the above, it could be coming from the boiler backdrafting; which would heighten the CO concerns.When natural gas burns, each carbon atom wants to combine with 2 oxygen atoms to form CO2. If there's insufficient oxygen at all points in the flame, some carbon atoms can only find one oxygen atom, and form CO. If there black soot, it's probably straight carbon where the burning carbon couldn't find any oxygen to combine with, indicating that a lot of CO is also being produced. (In almost all cases where I see carbon deposits on combustion appliances, I measure large amounts of CO - I don't know why I don't see it it a few cases, but subsequent repairs/service seems the most likely explanation.)Other than such testing, however, DO NOT use that boiler until it is serviced by a competent professional (which is easier said than done.) Try to find one who is a registered Building Performance Institute Carbon Monoxide Analyst, and,as Rob noted, someone who will analyze the whole building performace.As Dave noted, get AND USE use a carbon monoxide detector. At a minimum, get one with an LED readout: the UL standards for sounding the alarm will NOT protect you from chronic exposure at lower levels. (Under the UL standards, you still won't know about levels below 30 ppm)AIM Safety http://www.aimsafety.com is reportedly coming out with a CO health "monitor" which will register lower levels. I'm going to get some as soon as I can (and I check my house monthly with a Monoxor II and BPI protocol analysis!)Bob Walker
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Thanks for your replies.Once I noticed the soot I did purchase a CO detecter.Rob,to give you a little more info,the house is a ranch in New York that I am in the middle of renovating.I replaced most of the windows on the main floor.I also finished the basement making it considerably tighter with insulation in the walls and ceiling.The boiler and hot water heater are in their own room . At the time of the sooting there was no fresh air vent. I did not have this problem before I finished the basement.Since then I put a 4" vent for fresh air.Is that enough for a 100,000BTU boiler?I plan on removing the original attic insulation to seal any holes and put sheetrock boxes over all the recessed lighting.I would like to reinsulate with R-19 in the 2x6 floor joists and go over that with R-11 or 13 unfaced across the joists.Can you recommend anything else?Thank you for your help,Chas.
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Chas,
Rule of thumb is 1 sq in free vent space per 1,000 BTU. Thus, you need 100 sq in: typical vent covers reduce free vent space by about 50%, but its supposed to marked on the cover.
ASHRAE and many codes say to put in 2, one high, one low. (Don't forget to include any other gas appliances in the room, e.g., water heaters.)
You still need to test the functioning of the unit (CO production and drafting - see, e.g. the BPI protocol linked from http://home.att.net/~cobusters1/); especially as you're tightening things up. Rules of thumb don't always work.
Bob
*Chas - Lots of good advice from others here. All I will add is do not bother with the glass in the attic floor. Blow in cellulose, or sheet the ceilings with 1/2" foil faced iso before the rock goes up. Tape all the joints.The soot generation needs to be looked into, the accumulation on your walls may be due to pressure imbalances caused during the renovation like ceilings and walls gutted, etc. I would be surprised if the basement work did much to alter the presssure characteristics. I would suspect the windows more.Bob - regarding the "health monitor" I am aware of the condition you describe with the conventional detector and the 29ppm threshold, it is also a time weighted average, making them less effective. The digital readout is imperative. When I talked with Frank Vigil in April he said AIM had run into problems with the FDA and their use of the word "health." It was holding things up, and they apparently couldn't just backtrack and change the name.-Rob
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After this past winter I have noticed a oily black dirt on the walls above the hot water baseboard heating,on electrical outlets&switches,around pictures on the walls,and recessed lighting. I have been told that the boiler has carbon buildup,needs adequate venting in boiler room.I`ve also been told that the attic needs to be cured of all it`s drafts and proper insulation.Can anyone point me in the right direction to the cause of my problem before I repaint and have this happen again? Thanks in advance.