Heat Exchanger Location

[wvwoodchuck]

Has anyone here put a heat exchanger in the return air duct? or installed one at an angle in the duct work?

I know I've been asking a lot of questions, but you all have been a lot of help. Hopefully after this install, I'll be able to contribute instead of taking.

Thanks.
Tom

 

[bigburner]

don't put it in the RA duct, simple terms -- it's like stacking a furnace on top of a furnace.[can also cause the fan to starve for air] As far as an angle goes that is an accepted practice [AC coils are at angles and the vanes are off angle to air flow ] If you have room put in the biggest coil you can even if you need some transitions made. height is the problem in a lot of older homes. if you have branch ducts say running out each side of the furnace you could put smaller coils in each one. In this case a transition is almost a must. more surface area is better then thicker coil and this applies even more if you are already pushing the air threw an A/C coil.

 

[heating8]

try to locate it in the supply. DO NOT put it in the return if it's a heat pump unless you really know what you're doing and have done all the calculations. It's ok to put it in the return if it's a gas / oil furnace. Angled is fine, just make sure (depending on the coil) that you can vent the air (i.e. if the supply and return are right beside each other on the header you may have issues).

 

[wvwoodchuck]

Thanks. It is a propane furnace. I don't have enough room to lift the furnace and stick it on top of the A/C coil. The supply is an odd size, 18"x15" and hard to find a exchanger to fit in that size.

 

[twitch]

Tom,
I had a similar problem with my Tarm install. The hot air furnace was in the house with a very small duct opening. I ended up buying an air handler to put in the garage and tied into the existing duct work under the house.

 

[wvwoodchuck]

I believe I can put the exchanger in the return (almost right on top of the furnace) without too much trouble. If I put it under the furnace (it's a downflow) then I'll have to do some reconstructive surgery on the duct work.

 

[jashcroft]

Mine is in the return and I've never had a problem. I had a professional do the installation. Not something I wanted to attempt myself.

 

[Medman]

I also have a downflow furnace and I put the coil in the supply, under the furnace. I had to make modifications to the sheet metal and build a frame to hold the weight of the furnace. If you are not comfortable doing these mods yourself, the sheet metal guys are usually willing to do quick jobs like these for cash - ask at your local supply house for the names of some people who take the small side jobs. I did this to get an HVAC guy to sweat the copper lines for the AC and pressurize the system. I did everything else myself, and had no problem passing inspections.

 

[heating8]

the sheet metal guys are usually willing to do quick jobs like these for cash .

we're willing to do any jobs for cash

 

[wvwoodchuck]

Thanks everyone. I appreciate the advice. I've got a dealer (for another stove) to come and help me.