Thread: Styrofoam blocks supporting furnace

Split system HVAC system.

The furnace was in the attic on its side....it was rated for horizontal installation...however, the furnace , evaporator coil, and supply/return plenums were supported with styrofoam blocks rather than metal straps.

So , I'm thinking:

a) the styrofoam blocks do not provide the proper support for the system.

b) the sytrofoam blocks are combustible material , which are in contact with the furnace cabinets.

Are these defects?

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any thoughts on this subject?

bm

That is a HVAC or furnace? or have both in the attic? Do you have brand name and model number? Please clarify and attach photos.

Originally Posted by brianmiller

So , I'm thinking:

a) the styrofoam blocks do not provide the proper support for the system.

I agree.

b) the sytrofoam blocks are combustible material , which are in contact with the furnace cabinets.

That would depend on the required clearances to combustible material, which might not be a problem with electric strip heaters only.

Are these defects?

Yes, in my opinion, as the foam blocks are not intended to be used for that use, the foam can deteriorate over time, condensation can form between the foam and cabinet rusting it out, etc.

The one good thing about the foam blocks, though, may be that when the condensate line backs and overflows into the improperly installed secondary condensate line and overflows into the auxiliary drain pan, those "flotation devices" may help float the AHU float up and away from the rising flood waters.

the gas-fired furnace and the evaporator coil are in the attic. the condensor/compressor is out side.

Do not the majority of manufacturers require a minimum of one inch clearance from the cabinet?

Sorry no pics...

bm

Originally Posted by brianmiller

the gas-fired furnace and the evaporator coil are in the attic. the condensor/compressor is out side.

Do not the majority of manufacturers require a minimum of one inch clearance from the cabinet?

Depends on if horizontal or vertical, and the clearance above is greater than the clearance beside and below as I recall.

Also, as I recall, they are not to be supported by combustible materials?