Mold Growth Around Evaporator Coil

[rmmcneil]

My upstairs system began leaking water so I had it checked out. Appears the pan under the evaporator coil has rusted through and is allowing water to leak. When the technician pulled the cover off the evaporator coil housing I noticed the interior was lined with insulation that was covered with mold and bacteria. Is this normal? Also, is it normal for there to be insulation lining the inside surface?

For replacement of the coil, am I better off going with an uncased unit or a cased unit?

[t527ed]

if it is a horizonal system i don't think there is an uncased coil.:cool:

usually a self contained blower coil or a cased coil if it works with a gas furnace.

look for airflow problems making coil colder than it should be.:(

[rmmcneil]

System is a forced air furnace with the evaporator coil located above the furnace enclosure, then the supply plenum located above the evaporator coil enclosure.

From looking at pictures online, it appears I have a cased evaporator coil mounted directly above the furnace. Does this sound right? It just seems wierd to me for the enclosure housing the evaporator coil to have insulation on the inside - rather than just bare metal with insulation on the outside. Looks like the insulation on the interior would create air flor drag and provide a surface for the mold to grow. The insulation seems to be similar to an unfaced fiberglass... it's not smooth or coated with anything.

[hook]

Mold is a nasty thing for the health of everyone....get it out...with todays technology a UV light kills bacteria and mold.As for the insulation...it keeps the heat and cold where it belongs as well as reduce noise from the furnace plenum...this is normal and on most furnaces and cased coils unless its a builder's type or price competitive unit.(i dare not say cheap here)

[t527ed]

thats a cased coil alright but i have never seen one with mold in it.

not that i have seen everything there is to see...:D

if you are concerned about it uncased upflow coils are easy to come by.

[wheresivan]

Some times if your coil doesn't have enough pitch water will stay in the pan.Water sitting in the pan between seasons call cause anything to start growing.

[Shophound]

The leak in the condensate pan likely allowed water onto the bottom frame of the casing surrounding the coil. The insulation then wicked this water up into the insulation fibers via capillary action and evaporation, providing an ideal place for mold to grow. Cool, wet...mold spores are ALWAYS in the air and only need the right environment to lodge, germinate, and grow.

Cased coils are normally internally lined. Any air pressure drop caused via the insulation is accounted for in the design. If you are now faced with replacing the coil, it is best if the new one is the right match for your existing condenser.