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Central air makes my wife sick. Could it be dirty evaporator coil or drip pan?

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Waterbury Steam
Waterbury Steam Member Posts: 58

Every year when it starts to get hot out and we turn on the AC, my wife starts having persistent allergy symptoms. Mainly very stuffy and runny nose. It affects her sleep and my sanity, as she always wants to turn it off regardless of heat or humidity outside. We've tried getting the ducts cleaned, which didn't help at all, and I've been using MPR 1000 filters for years, replacing them monthly. That hasn't helped at all either. I'm wondering if it's possible that our evaporator coil is the issue. I don't think we've ever had it cleaned.

Some background—the evaporator is in the attic, as we use radiant heat during the colder months. She has no issues during heating season. The system is probably 25 years old. About five years ago, we had a clog in our condensate drain that caused the drip pan to overflow through our ceilings. We had the drain line replaced and it's flowing freely, but I don't think anyone ever did a cleaning on the drip pan.

So, I want to call a local company to see if I can get those things cleaned, but I don't want somebody to come out and blast everything with compressed air which will probably just make everything worse. So—is it plausible that these things are the cause of our issues? What kind of service is available and what should I ask for? Is disinfecting these parts a thing?

joechris9136

Comments

  • HVACNUT
    HVACNUT Member Posts: 5,870
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    There are cleaners specifically for evaporator coils.

    Have you tried running the fan only, without AC? Is it possible there's enough air leaks in the ductwork to be pulling in attic air? A Duct Blaster test can be done to measure for air leaks in the ductwork and air handler. Is it metal ductwork? Insulated outside or inside? Fiberboard?

    Was there water damage from the leak? No moldy insulation up there?

  • pecmsg
    pecmsg Member Posts: 4,909
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    what size A/C?

    What size resistance?

    where is this resistance?

    Pictures Help.

  • Jamie Hall
    Jamie Hall Member Posts: 23,543
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    It certainly is possible that the coil — or that vicinity — is the problem. In fact, I'd regard it as rather likely. Considering that you had a water problem once, and that coils do get damp or just plain wet when in operation, and it hasn't been cleaned… in my not so humble opinion you almost certainly have a mold problem up there, possibly a very serious one. Just blasting with compressed air isn't going to help — you need an AC professional to come in there and disassemble everything and clean it operating on the assumption that it is a mold problem.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Waterbury Steam
    Waterbury Steam Member Posts: 58
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    I tried submitting a reply earlier but it seems to have vanished into the ether.

    I do feel that it may be pulling air in from the attic, as I get a whiff of "attic smell" when it first starts up, especially if I'm upstairs. Also, I do recall that this air handler in the attic has a slot where ordinarily you'd slide in the filter but it's unused, because the filter is in the ceiling just below the air handler. A tech in the past said this was poorly sealed with tape and he tried to make it better, but wasn't confident it would hold. There was water damage to the ceiling when we had the plugged condensate line, and it would not surprise me at all if there's moldy insulation up there. The ductwork is metal with insulation on the outside of it. Honestly it's probably time to replace the whole system based on its age, but it hasn't been our no. 1 priority because it still works and we have other projects that need to be done first.

    Don't know the size of the system, house is 2800 sq ft. Does resistance mean the filter? That's in the ceiling just under the attic unit.

  • PDTech
    PDTech Member Posts: 7
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    While finding the source of the irritant should be first order, we also have a UV light mounted in the main duct. Its purpose is to kill mold spores. Its effect is helped by running the fan continuously on low speed. If the lamp goes out, my wife can notice the difference in just a few days.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,746
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    I would recommend a UV light. You can put one in the AHU. You can also buy a stand alone air purifier and put it in the bedroom. They make these with a UV light as well. I just bought a new one a Hunter.

    Other than that get someone who knows sheet metal to make a cap for the air filter slot and screw it in and seal it tight. I would have the evap coil and drain pan cleaned and disinfected

  • HVACNUT
    HVACNUT Member Posts: 5,870
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    @Waterbury Steam , your first post mentioned the air filter, and I believe it crossed to a 4 inch, MERV 11. But in a later post you mention a filter in the ceiling, which are typically 1 inch. Not that it's the cause of the odor, just trying to clarify.

    Do the DB test and get it sealed.

  • Waterbury Steam
    Waterbury Steam Member Posts: 58
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    "Have you tried running the fan only, without AC?"

    Yes, believe she has the same complaints when we do that.

    "Is it possible there's enough air leaks in the ductwork to be pulling in attic air?"

    This is very likely now that I think of it. When the system starts, sometimes I get a whiff of attic smell at first, a smell that I would describe as "hot wood". Also, I remember from a previous time that we got it serviced, that the tech mentioned the air handling unit in the attic has a slot where ordinarily you'd install the filter which is unused, as the filter is in the ceiling just before the handling unit, so it's accessible without going into the attic. He said that the access slot had been covered by tape which hadn't held, so there was an open gap. He covered it again with tape as best he could, but didn't have a lot of confidence it would hold.

    "Is it metal ductwork? Insulated outside or inside?"

    It is metal ductwork, insulated on the outside.

    "Was there water damage from the leak? No moldy insulation up there?"

    Yes, water came through the ceiling and there is some visible damage from it. Wouldn't surprise me if there was some moldy insulation up there.

  • Erin Holohan Haskell
    Erin Holohan Haskell Member, Moderator, Administrator Posts: 2,333
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    Sorry @Waterbury Steam. Your comment got held by our spam filter, but I've sent it through here. Thanks for your patience!

    President
    HeatingHelp.com

    Waterbury Steam
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,356
    edited May 19
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    Hi, While I agree that finding and fixing the source of the problem is the right way to go, your wife probably doesn't want to feel like a lab rat, being used to see how well the repairs are working. I recently had experience with a Zehnder energy recovery ventilator, which does a really good job of cleaning the indoor air. It's an expensive piece of equipment, but the concepts of good filtration along with dilution together very likely will give her the clean air she needs. Maybe this can be accomplished inexpensively with a filter: https://www.bing.com/videos/riverview/relatedvideo?q=corsi+rosenthal+air+filter&mid=DA3B2A4B07DD825D7DBBDA3B2A4B07DD825D7DBB&FORM=VIRE and a window fan blowing filtered outdoor into the house. Probably not the right approach in winter, but could help now. Keeping the house under a slight positive pressure will help too.

    Yours, Larry

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,153
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    Somewhere recently, I read a 2005ish post about how an ozone generator was used to solve a particular problem. Perhaps CO But not sure. It was an unconventional way to solve the problem that no one was able to solve. Also, I would not recommend that you just pick any ozone generator and turn it on.

    The ozone generator mitigated the issue, but there was an unbelievable side effect.  Everyone in the home is now much healthier.  The wife suffered from breathing issues and the daughter always had a mild headache.  (or something like that) The reason you don't want to just run out and grab the most expensive Ozone Generator that creates the largest amount of ozone and just stick in in you ductwork and spread it all over your home is… there are some folks that ozone has a negative effect on.  You should look into this but be prepared to abandon the device if you start to get sicker.  I would suggest a small inexpensive unit in your bedroom for starters.

    Gooogle Ozone Generators and look at both the pro and con side of the discussion. There may be some benefit in this.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    Larry Weingarten
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,153
    edited May 19
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    I found the article, it was involving something called Black Soot Syndrome. It came up in a discussion about how to stop getting those blackish stains that seem to appear like ghosts around air duct registers and on walls near baseboard radiators.

    @captainco posted a paper by Jim Davis. The part that was interesting for you I printed in bold type Below

    Black Soot Syndrome!

    Jim Davis - 2016

    The “Black Soot Syndrome” entered into my career in February 1997… 

    look at the complete text from that paper in the above post. It is in the thread posted by @captainco

    …In this case the house was ten years old, but the basement had just been finished in the last 6 months.  Black soot was starting to show everywhere in the whole house.  The people couldn’t touch anything without getting black on their hands.  The lady of the house had chronic respiratory illness, and this was making it worse.  They had spent over $5000 getting the house cleaned and the soot began showing up the next day.   She was in misery and wanted help and was told she might have a carbon monoxide problem.  When carbon monoxide was mentioned I was considered the person in the know, so I got a call from a HVAC contractor for help.  The furnace and water heater were tested and found totally safe, with no signs of sooting whatsoever.  That left me to believe it must be the same VOC problem I had seen before.  In the previous cases people had just opted to move.

    With a guarantee that if it didn’t work, the Ozone light would be removed, and the customer would receive a full refund, the HVAC contractor installed a duct mounted O-zone light. On the second day the homeowner called and reported no signs of additional sooting for the first time in months.  Usually the television or computer screens were the most noticeable to have some buildup day to day and they were spotless.  After about a week the contractor received another call asking just what does that Ozone thingy do?  He explained how it destroys VOCs, pollutants, bacteria, virus, spores etc. and of course asked the customer, “why the concern”.  It was more amazement than a concern because the homeowner detailed how most of her symptoms of her respiratory illness had been reduced drastically.  She hadn’t felt that healthy in years and needed minimum medication.

    Sometime later, another call came in with the same problem in a double-wide mobile home.  Black soot was everywhere.  A daughter who was living with her mother called a contractor.  Somehow, he contacts me because of a suspected CO problem.  Upon discovering there was no CO problem, I told them of the previous situation.  They agreed to have an

    Ozone light installed with the same promise if it didn’t work.  Within a few days the call came in thanking the contractor, because signs of new soot developing were gone.

    After a couple of weeks, the call is received asking what all does that O-zone thingy do?  Why do you ask?  Well my mother who has cancer (which we didn’t know at the time), is like a changed person.  Her energy levels increase substantially, she got some color back and it was almost like she wasn’t sick any more.  What an unexpected and satisfying comment that was to hear!  We were just trying to alleviate the black soot problem.  I could only conclude at this point that all the negativity associated with Ozone generators and its unhealthy affects on people may not be as well founded as many have been led to believe.

    What about all the reports or tests that have stated low level Ozone was ineffective in treating indoor air quality??  As far as I am concerned it doesn’t matter because the problem was being addressed and removed. The actual results should be the only thing that matters and what we put our trust in.

    Although the “Black Soot Problem’ does not get the attention it did in the beginning, it is still out there and causing problems everywhere.   It is your choice when confronted with this problem whether you want to help solve it or just walk away.  It can be a Win-Win or a Lose-Lose situation.

    P.S.  Additional information has been posted on this subject stating that VOC’s could be absorbed into other porous materials in a building and continue to outgas for an additional 5 years or a total of 10 years.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • Waterbury Steam
    Waterbury Steam Member Posts: 58
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    In regards to Ozone, she does not want an ozone generator in the house. Not sure where the opposition comes from, but she may have had a negative reaction to one in the past.

  • Jamie Hall
    Jamie Hall Member Posts: 23,543
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    Hoofbeats? think horses, not zebras. You had a moisture problem. You now almost certainly have mold — on the evap. coil, in the ducts, in the surrounding spaces. The stuff doesn't go away. Get it thoroughly washed, disinfected (chlorine containing compound to wash), and then put back together and see what happens. Then go fancier if need be.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • kcopp
    kcopp Member Posts: 4,446
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    How about a couple window units to get you through? Simpler and may be less money and aggravation…

  • pecmsg
    pecmsg Member Posts: 4,909
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    all UV lights do is break brown plastic and wire ins!

  • SuperTech
    SuperTech Member Posts: 2,201
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    Out of curiosity, do you close up all your ceiling diffusers in the winter? I've seen that lead to different results ranging from the air handler filling with mold to the flexible ductwork filling with several gallons of water. This seems to only be a problem in the northeast where the ductwork is only used for cooling and the heating is provided by a hydronic baseboards, radiators or radiant floor heating. People think they are loosing heat to the ductwork and close the vents without thinking about the consequences.

  • mattmia2
    mattmia2 Member Posts: 9,840
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    With the filter being in a holder at the return grill, especially a very restrictive filter, the blower is going to really pull in the stuff from the attic through any leaks in the duct work or air handler cabinet and distribute that stuff. It might be worth moving the filter to the intake of the air handler where it will be a lot easier to make it so it is only pulling air through the filter.