Air handler supports

Saw an electric heat pump split system today.

When the air handler with heat strips is located in the attic, do the supports for the unit need to be non-combustible material? This was mounted on a wood frame instead of a concrete blocks, etc.

I assume (???) they would non-combustible for a gas furnace, but what about electric?


Typical attic installation here is metal tray (with drain or overflow protection), 2x4 blocks in pan with air handler on top.

At some point in the not far past, I thought the unit had to be standing on non-combustible base in the pan. Couldn’t find the reference when I got to looking.

A good many we see have some type of brick or block supports.

I see virtually all attic air handlers on wooden supports around here regardless of fuel source. While there may be a code to the contrary, IMHO the outer casing/frame of such units is so far away from the heat source as to make it a non-issue. If high-temperature energy should penetrate the enclosure there is so much more cumbustible material in an attic to worry about. That’s why in my personal home, I have smoke detectors in the attic reporting to my alarm system.

Should be OK for electric