Amana downflow and A coil

[sotterbein1]

A homeowner question that will help me sort out some contractor advice. I am getting estimates to add a/c to an existing Amana Air Command 80 gas fired furnace. One contractor says it has to be replaced with another heater and another says it can take the a coil. The furnace is in an addition, second floor, in an enclosed space. The Amana sits on sheetmetal box 17" h and 24" deep. It appears the air is forced out to the right for distribution to the ductwork. Contractor A says this space limits the coil's efficiency and will likely even freeze over because the air will not be in the direct path of the coil. The new equipment will be Carrier. The Amana is 10 yrs old and I would not rather replace it yet as it works fine. Any advice? Scott

[4l530]

I don't know why the furnace would have to be replaced, but I don't see an A coil working too awful well in that box either. If that's where you're wanting it put.

[sotterbein1]

When i asked about this problem the contractor said he could put the A coil on top so the cool air would flow thru the return side of the furnace. My other contractor says it will rust out the heat exchanger in two years. Don't know who to believe.

[dokktor]

I think that Amana furnace has a stainless steel tubular heat exchanger in it, but I'm not positive -rusting may not be an issue. However, if there is room to mount it in the return duct, wouldn't it be possible to install a larger box underneath the furnace to lift it up??

[RoBoTeq]

When i asked about this problem the contractor said he could put the A coil on top so the cool air would flow thru the return side of the furnace. My other contractor says it will rust out the heat exchanger in two years. Don't know who to believe.

Whether it rusts ferrous steel or corrodes stainless steel (and it will), you do not want to put a coil in the return.