Condensation forming at exterior of fan coil unit cabinet. The formation of condensation at the exterior of an evaporator cabinet is due primarily to cold surfaces coming in contact with warm air. In many cases condensation of this type is due to deteriorated or loose insulation within the evaporator cabinet. Other times the problem is due to dirty evaporator coils, clogging, and other various reasons. Further evaluation and repairs are needed by a licensed air conditioning contractor. This is not an immediate need, but one which should not be neglected too long, as premature rusting and resulting leakage can occur over time.
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Condensation at tape spanning ductwork joint: Condensation is noted at taping along the top of the main duct where attached to the evaporator. This generally occurs in areas where taping is spanning a gap with cold air on one side and hot attic air on the other, resulting in the formation of condensation at the exterior of the taping. Condensation can promote rusting in air conditioning units over a period of time and is not desirable. This joint between the main duct and the evaporator unit should be properly reconstructed by a licensed air conditioner contractor when time permits.
-- Joseph Burkeson, RPI (Hooperette)
?Anyone who has proclaimed violence his method inexorably must choose lying as his principle.?
~ Aleksandr Solzhenitsyn
Originally Posted By: dandersen This post was automatically imported from our archived forum.
And yes, it’s mold!
You can:
1. Do air quality testing to determine that it is mold.
2. Or you can use a bleach based cleaner and remove it from the since surfaces before it spreads.
There is very little you can do to effectively correct this situation when you live in a location where you have extremely high humidity levels in the outdoor air. If you look on the psychometric chart, you'll notice that it only takes about a 15? drop in dry bulb temperature to reach the dew point temperature (where condensation forms) at 60% relative humidity(6? @80% Rh) . As a general rule (however one I do not agree with) home inspectors are looking for a 20? drop in supply/return air temperature. Even if the air conditioner were located within the conditioned space within the house, you will be condensing water. Even if you insulate, the insulation may condense.
If you increase the air flow through the air conditioning air handler, the temperature difference will drop and you may not reach the dew point temperature on the outside of the air handling unit. But, then you will be reporting on the Delta T drop.
This condition is primarily a housekeeping matter in my opinion. It's like cleaning your shower. When it grows you clean it off.
Condensation forming at exterior of fan coil unit caninet. The formation of condensation at the exterior of an evaporator cabinet is due primarily to cold surfaces coming in contact with warm air. In many cases condensation of this type is due to deteriorated or loose insulation within the evaporator cabinet. Other times the problem is due to dirty evaporator coils, clogging, and other various reasons. Further evaluation and repairs are needed by a licensed air conditioning contractor. This is not an immediate need, but one which should not be neglected too long, as premature rusting and resulting leakage can occur over time.
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Condensation at tape spanning ductwork joint: Condensation is noted at taping along the top of the main duct where attached to the evaporator. This generally occurs in areas where taping is spanning a gap with cold air on one side and hot attic air on the other, resulting in the formation of condensation at the exterior of the taping. Condensation can promote rusting in air conditioning units over a period of time and is not desirable. This joint between the main duct and the evaporator unit should be properly reconstructed by a licensed air conditioner contractor when time permits.
Gary:
Joe is right on the money. The cause is the humidity from the garage and the temperature of the PAPER tape used to construct the plenum. If the builder had used foil tape, this would not have occurred. You need to check the coils as well. The affected area needs to be removed. If the ductboard has been contaminated, that too needs to go. South Florida estimates will be between $400-800. If the coils are in need of cleaning, the cost may rise another $400. There is a good possibility that the IAQ should be considered for testing. Look at the rest of the registers. You may find condensation near the closest registers to the A/H.
Originally Posted By: whandley This post was automatically imported from our archived forum.
Bleach base cleansers won’t completely kill and or remove various mold spores. Research Borate based cleaning materials, such as “Borax Soap”, Borate will kill mold spores on the surface material as well as mold spore root systems imbedded in the material.
An excellent reference book on mold is available right here on the NACHI site:
"Black Mold - Your Health and Your Home"
Richard F Progovitz, Author
The Forager Press, LLC
www.theforagerpress.com
$16.95 USD