Thread: Up flow Furnace wood Base

Weather King Furnace. Goggle search indicates made bt Ruud/Rheem. Serial number indicates 80PS-Series. My question is if the wood base is appropriate.
The wood base box is also the return air. Web page spec sheet below. Anyone see anything that would cause a concern? There is a warning section on page 7. Does it relate to this issue?
Rheem AC: Heating For Your Home

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Dave, I don't see any real concern with the wood floor base. The fan motor compartment is located at the bottom w/the heat exchanger above allowing for the proper clearance for combustibles. The bigger issue in this type arrangement is the primary drain line,it's located in the return air box located directly below;you want to make sure that it is sealed off preventing sewer gasses getting sucked into the the structure..

Originally Posted by David Banks

Weather King Furnace. Goggle search indicates made bt Ruud/Rheem. Serial number indicates 80PS-Series. My question is if the wood base is appropriate.
The wood base box is also the return air. Web page spec sheet below. Anyone see anything that would cause a concern? There is a warning section on page 7. Does it relate to this issue?
Rheem AC: Heating For Your Home

David,

Your Photo shows the front of the furnace & the wood box is the return & the warning on page 6 of the Spec.sheet says a metal plate is required if side return air ducts are present then it needs a solid metal plate per Manufacturers Instruction.

Originally Posted by Billy Stephens

David,

Your Photo shows the front of the furnace & the wood box is the return & the warning on page 6 of the Spec.sheet says a metal plate is required if side return air ducts are present then it needs a solid metal plate per Manufacturers Instruction.

Billy. Thats my confusion. What do they mean by metal plate? Does not seem to be a side return but a bottom return.

Originally Posted by David Banks

Billy. Thats my confusion. What do they mean by metal plate? Does not seem to be a side return but a bottom return.

David,

I'm no HVAC tech for sure.

The solid metal plate is an accessory kit .

The Warning about the Solid metal plate for side return vents is on the Up flow accessory page.

My take is the return opening on the sides of the bottom are side return vents.

The typical arrangement on an up-flow furnace around here is an open bottom to mount as an updraft like your have in your picture (ok, maybe not as sloppy as in your picture!) The metal plate would be used to close off the bottom if a side inlet kit was used. This does not enter the equation for what you have pictured.
What is with the dark photos today? Turn off the flashlight or direct it away from the subject and use the flash, dude!

Originally Posted by Jim Luttrall

--The metal plate would be used to close off the bottom if a side inlet kit was used. This does not enter the equation for what you have pictured.

Thank You there Mr. Inspector.

Don't forget, that wood box is likely not an acceptable material for a return air plenum (at least not where I am aware of), it would either need to be lined (duct board) or the return duct connected directly to the unit, with the wood box acting only as a 'platform' and having no contact with the return air.

With that thing setting off to one side like that, I'd be concerned about how it is sealed to the plenum or duct - you don't want any of the air around it to be drawn into the return (that's combustion air all around that unit and the gas water heater, plus that return would try to back draft the water heater and the furnace).

Our local code requires 'non-combustible' base even for upflow units. A good hvac guy uses a metal airbox, not plywood. I would also be concerned about biologic growth in the plywood box. I wouldn't consider it a safe or proper install.