InspectAPedia®   -   Search InspectApedia

Photograph of rust and leakage inside of an air conditioner Leaky, Moldy or Wet Air Handler FAQs
Q&A on Leaks & Mold Problems in HVAC Blower Compartments & Ducts

  • POST a QUESTION or COMMENT about leaks in air conditioner or heat pump or furnace air handlers and how to test HVAC systems for mold contamination

Air handler blower unit leaks & mold hazard FAQs.

This air conditioning repair article series discusses the problem of A/C condensate leaks into air conditioning system air handler units, blower units, or AHU's, (also called fan coil units).

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Airh Handler Blower Leaks, Rust, Mold Q&A

Photo of water stains, rust, and possible insulation in air conditioner air handler fiberglass insulation (C) Daniel Fr4iedmanThese questions & answers about Air Conditioner Air Handler Rust, Condensate Leaks, Wet Insulation, & Mold Hazards were posted originally at BLOWER LEAKS, RUST & MOLD - be sure to check out the diagnostic advice given there.

On 2018-02-21 by (mod) - mold contamination in fiberglass insulation

Nicole,

Because it's often impossible to see, with the naked eye, mold contamination in fiberglass insulation, if insulation has then actually wet and or if it is indeed visibly moldy on the surface or smells moldy, it should be replaced.

Beyond that point, making a specific moisture measurement, for example confirming that the moisture is below 18% - the critical threshold for mold growth - might be useful but it is absolutely not reliable if the results are negative.

By that I mean if you find high moisture and insulation at least raise a question of mold contamination or the invitation to mold growth. I just said that would be above 18%. However the absence of moisture is not proof that the installation has never been wet nor that it is mold free.

His reasoning I would look more generally at the conditions in the air handler for signs of leaks or soaked insulation.

If you're going to go to the trouble of fixing a problem like that make sure you find an address the water source as well. I'm less concerned about superficial wetting on fiberglass insulatong panels that were coated with a waterproof surface.

See FIBERGLASS INSULATION MOLD

On 2018-02-21 by Nicole

@Paula,
I would check for mold I had the same problem than turned to musty smell. Each time I turned on heat and or air made worse. I too have allergies and mold has made me sick. It may be where you cannot are or under insulation. Hope that helps a bit! Gl.

What is the optimal moisture reading percentage for the fiber glass insulation in the air handler and inside the hvac unit all together. Ty. Have existing mold and need to know if insulation must be changed

On 2016-06-20 by victor ramos

My motor blower doesn't turn on in the furnace does the unit outside have to turn on
Do I need a new motor blower


On 2016-01-11 by Anonymous

Green mold under beds on lower furniture, small spider webs with white eggs under all furniture

On 2015-12-12 by (mod) -

I don't have enough information to offer a useful diagnosis, Paula. I'm guessing you're talking about a heat pump that can be switched between heating and cooling mode.

If so, the ductwork, fan, and all air handling components are the same in the two modes. What's different is whether or not the aux heaters run or whether the heat pump runs in cooling mode or heating mode.

A more thorough on-site inspection of not just the HVAC system but possible odor sources is needed.

On 2015-12-12 by Paula

I have a problem with a sweet sickening smell when I switch from the heater to AC. I have severe allergies and asthma and an unknown couch that cannot be diagnosed.

I need some help in what to do. If the AC ONLY runs, you do not smell it.

However, if you have a cold morning and you turn on the heater and then have a hot afternoon and turn on AC, you get that sweet smell that makes me sick! I have had to tech guys out and they both have "cleaned" the coils, but it still stinks. I am running out of options and I am desperate for a fix!

On 2015-08-27 by (mod) -

Mike and Anon,

These articles should help you out; let me know if you have specific questions

See these articles that discuss causes & remedies & tests for mold contamination in HVAC ductwork. Through them you'll find more reading suggested at the ARTICLE INDEX.

https://inspectapedia.com/mold/Mold_in_Air_Ducts.php

https://inspectapedia.com/Fiberglass/Fiberglass_Insulation_Mold_Causes.php

https://inspectapedia.com/aircond/Air_Handler_Leaks.php

On 2015-08-26 by Anonymous

Mike, did anyone answer your question? My husband and I are interested in the same thing

On 2015-06-27 by Mike

I have mold in my ac cold air trunk and all ducts. I want an independent evaluation of the root cause of this problem and not have to rely on my AC contractor. In my mind, this would be somebody who has no financial interested in duct cleaning, or remediation equipment or repairs.

On 2015-06-02 01:25:15.801980 by (mod) -

Darrell

Probability of detectable mold = 1.

Probability of a dangerous or harmful mold contamiantion: we really can't say, nor can we imagine that the 2 pound weight was really all mold. But certainly the sudden increase in air velocity of removing dirty clogged filters would be expected to blow whatever is in the duct system and air handler and blower fan itself out onto the building occupants.

I'm doubtful that either the HVAC tech or the manager were actually qualified to make an evaluation of mold hazards.

On 2015-06-02 by Darrell

Filters in air handler at my wifes work had not been changed in around 4+ years,air flow got reduced and when handler was opened mold was found on both filters,the guy that removed the filters said they weighed about 2 pounds each had so much mold on them. After they were replaced they turned on the fan and said needed to blow the stuff out.

Wife told them she was allergic to mold and would be sick and she is! The general manager said he looked in the air handler and said no mold was in it.

What is the probability that there is mold still in the handler and duct work?


...

Continue reading at BLOWER LEAKS, RUST & MOLD - topic home, or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES. or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Air Handler / Blower Unit Articles

Suggested citation for this web page

BLOWER LEAKS, RUST & MOLD FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to AIR CONDITIONING & HEAT PUMPS

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Comment Form is loading comments...

Citations & References

In addition to any citations in the article above, a full list is available on request.


ADVERTISEMENT