metal heat pump cabinets and mold

[welshju]

I am in the process of obtaining estimates for a new heat pump. A salesperson from a company selling American Standard told me that most metal heat pump cabinets located in attics will grow mold because of condensation (hot attic versus cold coil). Is this correct? If yes, it seems that American Standard is my only option because that cabinet is non-metal (it was described as like a refrigerator) and therefore would not have the mold problem . Please advise and thanks so much!

[jtrammel]

He's a salesperson.

[billygoat22]

Trane is the same as well. even plastic will sweat if surface temp is below dew point.

You either need to raise temp of exterior of unit, or lower dew point in space.

In my part country its crawl units that sweat, rarely attic units unless missing insulation inside or low airflow issue makes cabinet overly cool.

you could also relocate airhandler to conditioned area, or do something w/attic immediately around unit to create an enclosed space around it.

[welshju]

Thanks. I don't know if my unit has this problem but will check when the new heat pump is installed. I decided to go with another metal cabinet because I liked the (what seemed to me) more professional approach of the other company rep.