3280 furnace

[jerryb]

I remember a while back someone, maybe Gruffy had checked their furnace and found some loose duct work so I pulled the grile for the cold air return and the cover on the back side to check mine out. Each side has 2 metal twist off covers about 5" in diameter, only one of these covers has a flexable vent hose about 3" in diameter. Is this the only duct? Is there a duct under the furnace? I took one of the covers off and looked but found no other opening. If thats the only duct out I may do some modifying.

[faeb and genb]

jerryb I haven't checked ours. we have plenty of heat when we use the furnance. Most times we use electric heater.
Gene

[Montana_657]

Good morning... I bet the 3 inch duct goes down.. that is the heat for the tank spaces. In mine it's a flexible silver thing... sort of a foil I guess.

On the 3670 the hot air goes through a large tin duct to the stair. Under the stair is a plenum where it separates to flex duct into the bed and bath area, and 3 x10 tin duct under the floor in the lounge.

I suspect the 3280 is a bit different...sorry.

[jerryb]

I had the stair open and checked out that plenum.
There must be an opening under the furnace for the plenum, the 3" flex hose does go down but in the area that would be in line with the floor registers. When it gets cold I'll check it out by plugging it and find out what quits.

[Ishler]

Just a little update to Gruffy's information, in the 2005 3670 the tin duct goes all the way to the front basement wall and up to the bedroom. They've eliminated the flexable ducts.

[Montana_657]

That sounds like a real improvement. Those flex ducts are always in the way. Did they insulate the duct in the generator compartment?? Or did they move it?? Our bedroom heat register is exposed to the great outdoors in the genny compartment. I wrapped it with insulation but still have to figure a way to insulate the floor.

[Ishler]

The duct doesn't go into the generator compartment, it stops behind that wall and goes verticle into the floor of the beedroom, and appears to be insulated, although I havn't had a reason to disassemble it. It's an extension of the rectangular floor duct.