Burning Chemical smell from A/C vents

[Evanesce]

I have a 1992 Commodore manufactured home 68x29 and I have noticed a burning chemical smell in my house that seems to be connected to the central A/C.
However, the burning smell can occur whether or not the A/C is on (it sometimes begins when the A/C has been off for several hours or overnight).
There are two rooms in my home with the A/C vents closed and no smell occurs in these rooms. It is hard to breathe when the smell is present and when I open a window the smell dissipates immediately (unlike burning something on the stove which takes a while to clear). This makes me think that house pressurization may have something to do with it. This smell occurs several times a day, everyday. It can occur in rooms located on one end of the house, but not the other and then it changes to the other side and sometimes it is throughout the house. The smell of burning chemical was so strong last night I had to turn off the breakers to the A/C and furnace. There is no smell yet today. I live in a very rural area without many HVAC experts. I am very concerned about breathing this chemical. Please advise. Thank you.

[rmurray]

You have not mentioned when this started....I sounds like you will have to call one of the few HVAC techs in the area...A 15 year old system can have many surprise problems....Might be a good time to schedule your annual furnace maintenance. I would not delay just in case it is electrical related..Shorts can cause fires..If is goes away when breakers are turned off...It is likely to be electrical in nature..

[Evanesce]

I have had the annual maintainance, but the tech does not know what the problem is. I should explain that in my area folks are not well trained and most people here do everything themselves, including building their own houses. So it is left to me to figure it out. Could an electrical short cause this burning chemical smell off and on?

[Evanesce]

I'm sorry, I forgot your question. This burning chemical smell has been going on for a month.

[admin]

From your description it sounds like the motor of your AC unit might be burning, this can cause an obnoxious burning odor thru the house. It is probably more noticeable in the room closest to the where the AC is connected to the duct system. The smell stops when you open the window because your ventilating the house.

If it is not the AC anything that smells like an electrical problem can be very dangerous It is not a good Idea to be breathing the fumes. The longer you wait the more likely it will be that replacement rather than repair will be possible, and the more it will cost you. You are exposing yourself and your family to possible health problems and a risk of fire.

I also live in a very rural area, and hate to pay someone to come work on my house. Its a long way out and the charges are always high. It is imposable for anyone to tell you what the problem is without being there. Your home is fifteen years old and it would not be unusual to require repairs of just about any type after one hundred and eighty months of use. Get some professional assistance today!!

[Evanesce]

Thanks for your help!

Someone came out last night and said they smelled benzine or benzene (they did not specify which). They noticed that the motor was running very hot and found the capacitor was at 50%. They replaced capacitor and so far there has been no smell.

BTW Could you please tell me if the A/C drip line should drop down from the bottom of the A/C onto the crawl space floor and and then over and up again about 3 feet (like a U shape) as it exits the crawl space through the block foundation? One person said that the 3 foot dip was needed to stop air from leaving the A/C. Another person said that with that dip (bend in the line) water would collect in the drip line and never be able to leave the drip line.

[admin]

I have never heard the theory about not letting air leave the AC via the drain line??? To the best of my understanding the drain line is gravity operated and should drop lower and lower and not turn up... if there is a low spot it seems that water would gather there.

You should clear this line from time to time to prevent any accumulation of "gunk" that drips of the coils with the water. We have 2 dogs and it seems no matter how often we change the filter that some dog hair accumulates on the coils and washes down the drain line.

My wife runs Clorox thru the drip line a few times a year to clean it out and kill any mold growing there... ours is a long three quarter inch PVC pipe that runs from the bottom of the unit under the house and out the skirting where it ends just above the ground. Phone the guy that just made the repairs on your machine and ask him what he recommends for flushing the line.

It is also a very good idea to open the machine and clean the coils at least once a year. For the most part the average homeowner IS NOT able to repair their own air conditioner unit. Many of the repairs will involve removing the Freon and that requires special equipment and you must be licensed to handle the Freon. But a homeowner can keep the condenser and evaporator coils clean which will help the unit last longer and cost a lot less in electric to keep the house cool. . See the free article Cleaning Your Air Conditioner for easy step by step details.

[Evanesce]

When I came home around 6:30 tonight the A/C was on and the chemical burning smell was overwhelming and throughout the house. I turned off the A/C and opened the windows and the smell went away. Around 9:30 tonight the smell came back at the kitchen sink facets. This smell was very strong and a distinctly a heavy burning smell. I am thinking this must be an electrical short that gets worse when the electrical load increases. Is that possible? If so, what should I expect an electrician to do (if I can find one who is licensed).
Again, thanks so much for your help.

And thank you for the information on drip lines. That makes sense. Perhaps my question gives you an idea of the diversity of opinion I am finding in this rural area. Most of the people here doing this work are out-of-work coalminers just trying to keep body and soul together. They lack the training you would find in more densely populated areas.

[admin]

Opening the windows is not really solving the base problem... it just vents the house so you are not aware of the problem for a short time. Just because you dont smell it at the moment is not an indication that the problem is not active. Dont let the lack of the smell give you a false sense of security.

Anything is possible but a burning smell from the sink is not likely... do you have a garbage disposal under the sink ?? is your breaker box in the utility room near the kitchen??? Check the breaker box, wherever it is, and see if it feels warm anyplace... it is possible that you have an overloaded, loose or faulty breaker that is burning.

Again this or any electric burning smell can be an indication of a very dangerous situation. Whatever is burning could start a fire that could take your home and anyone who might be in it at any time. I would be scared to spend a night sleeping there. You absolutely need to get some real professional help before you have a disaster on your hands. Get out the local yellow pages and get a real electrician to resolve your problem.

[Evanesce]

I got some today. I began with the Deputy State Fire Marshal (who I know slightly) and he recommend Jack, a Licensed Home Inspector who is excellent and has done work for me before. He was too busy, but consulted with me on the phone to try to isolate the problem. Then I called the Fire Marshal's office close by in another county, and he said that I need call the state Emergency Management office and say that "this is an emergency." They could not offer any help and explained that resources are so limited here, that basically, if you have a fire, the fire department will put it out - that's it. Then I contacted a very knowledgeable engineer with the Public Service Commission, who consulted with me on the phone, twice. I was able to get a HVAC contractor to come by. He went over everything from plumbing to crawl space to roof, according to the engineer's ideas. No way it is coming from the outside. He used an amp probe in the panel and checked everything but the furnace because someone had removed the pump to test it and has not brought it back. He found no problem with the electric. I also spoke with a toxicologist with the state department of environmental protection who will try to get the Health Department out here -- no guarantees. Finally, I got an Industrial Hygienist from the University to bring a meter out and she checked every imaginable place in and around my home. She got VOC readings in my home office of 1.5 (really high) and VOC readings in my kitchen of . 5 (too high). The CO2 levels exceeded 700 (way too high) and she concluded that the source was definitely in the house. She will not return and know of no one else to contact. Any ideas. I am desperate. Thank you.