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New HVAC problems

Dee7004 | Posted in GBA Pro Help on

I recently had my hvac system and all flex duct replaced due to age of unit and mold throughout. I live in a Florida 1930’s home and the ducts are in the crawl space under the house, also we have had a problem with critters making holes in the ducts.

This is what the ac people have done. Replaced unit, redid duct work, removed vent boots which had old moldy broken up duct board. They were scraped, cleaned and relined with duct board. I can still see where the old board was because it came up a few inches higher than the new and there are remnants of old fiberglass visible. The sheet metal plenum which sits on the ground also had old duct board and was cleaned and relined. Both the boot and plenum duct board was sealed with mastic.

I am not in good health and was very concerned about the mold. In my desperation to have this all redone I failed to do research on products and their chemicals. I did get several quotes but failed to educate myself on proper installation.

My problem and question is this. When turned on there was a very bad chemical smell which I was told was the mastic and would dissipate in a week or so, my nose started running, and strange stuff began draining from my eyes, and headaches. This I understand could be caused by an allergy from one or more of the chemicals’ in various products. And I suppose could be tolerated. But, i also started to get chest pain that was only alleviated somewhat by fresh air. After reading articles and blogs on this site it seems that the fiber board should not have been put in the metal boots but rather insulated on outside, due to the fact that the fiber board is susceptible to mold, and has numerous hazardous chemicals, it also restricts the air flow. The plenum sits on the ground so I don’t know how else it could be insulated. I am now (after the fact) aware of the many chemicals in the mastic and the fiberglass duct board.

It has been one week since this was completed; I’m not sure what to do. Does anyone have any suggestions, or knowledge to share on proper insulation or health problems?
I am quite desperate at this point. And response would be helpful.
Thank you
Dee

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Replies

  1. fitchplate | | #1

    Dee … so sorry about the outcome of your renovations. I am not sure you could have prevented it by better research. Your HVAC system works by moving air, filtering air, cooling air and warming air. It has to have a fresh air supply as well. Likely you are reacting to existing particulate that is entrained (recently disturbed and made airborne) or newly added to the HVAC systems air flow by the construction, or both.

    Crawl spaces cause illness and strong reactions from animals and insects, and sometimes by left over construction waste (dust, powders, etc) and sometimes contaminated soils (i.e. recently disturbed soils); etc. New materials are unlikely to have developed mold so soon. Your acute and immediate reaction resembles what I have seen as reactions to animal, insect and bird waste, nests, etc. Some animal saliva used to make nests and some animal faeces are very toxic to humans and reactions to inhaling them can be acute and immediate. Mouse and rat faeces are extremely dangerous and can be deadly.

    The construction is likely to have done a couple of things:

    - Opened your HVAC system (temporarily or perhaps permanently) to the entry of animal and or insect waste, hair, dried faeces; etc. Birds, rodents (large and small) and insect (like ants and termites) dung, nest and decaying bodies can be very toxic and cause almost immediate reactions like you have described.
    - Workers may have inadvertently contaminated your new ducts or disturbed deposits in old ducts with any of these sources and/or did not clean the ducts after installing.
    - Construction or other forms of waste disturbed and left around the building; on the lawn; etc where it can blow into open windows, be tracked in on shoes, or be inhaled by your fresh air intake.

    I would do a couple of things before I look to mold as the source.

    - Have someone you can trust examine the installation to make sure your HVAC ducts are properly sealed (taped) and that your fresh air intake or any ducting gaps are NOT taking in air (particulates) from the crawl space.

    - Examine the crawl space for any animal waste that can be removed (carefully). Check all remaining old ducts and newly installed ducts for deposits of dust and particulates; perhaps have a duct cleaning company vacuum out the entire system, including the plenum; have the HVAC heat, AV and fan motors and units serviced; install new filters.

    - Leave the house while this work is being done and preferably for a couple of days. Have the living space of the house vacuumed and cleaned before you return.

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