In installing a forced air furnace, is there any reason why I can’t suspend it from the roof rafters in my garage, about 7 feet off the floor (the garage roof is about 12 feet high)?
This would allow me to get the condensate easily into a P-trap in the adjacent laundry room, and would also give me more usable space in the garage. At first glance it seems weird to see a furnace “hanging” along the wall in midair, but is there any reason (or code) that disallows this?
I guess one obvious potential drawback would be more complicated servicing/maintenance, but I am looking primarily for things that make this illegal rather than simply impractical (though I’d be curious about both). FWIW, I’m in Southern CA. I plan to ask my inspector on Monday, but any a priori knowledge would be helpful.
Thanks in advance,
Leon
Edited 2/28/2004 12:44:06 AM ET by leon
Replies
Ask the furnace manufacturer what their mounting requirements are.
OK in the garage, but you cannot use the flexible plastic duct cause they may penetrate the firewall. So 22 guage (I think?) ducts will be required.
Leon,
Seems like I have seen a unit that was made to be suspended. I think it was in a crawlspace with a dirt floor that I saw it.
It was a long time ago so I could be mistaken.
good luck.
gk
Edited 2/28/2004 3:28:21 AM ET by gabe
As Dan said, find out if the model you have can be hung first. Then make sure your rafter/joist/ceiling will support the point load. If the furnace weights 200 pounds and is supended at fout corners, you get 50 lbs. per point. Depending on span,joist material, and location of the unit, you could end up creating more problems than the location of a condesate drain warrents.
Dave
Can you do a wall mounted platform, and save the car space below?
If only for the drain, you could get a condensate pump, but understand space is also a goal.
I don't like to see the way many are suspended. I have seen some that broke the back of the air handler when a side panel was removed. If you can put it on a sturdy platform, put a sheet of foamboard under it to rest on, and it will eliminate a lot of vibration. Servicing with a step ladder against a shelf will be safer than something suspended that can swing. Also, a stable base will be better for the metal duct connections.
Hope this helpful for discussion with inspector. Paul
Many manufacturers make units intended to be hung horizontally. You're best off if you buy one made for hanging. All the supports and access are already configured to install the unit easily.
They just installed a 4T furnace like you are describing in our attic. It is part of a heat pump system.
It is suspended from the rafters horizontally by some eight chains, at least, four to the side.
It has a drip pan below built integrally that has it's own drain, that if it ever shows to have any water off it on the outside of the house drain spout, I am supposed to turn everything off and have it serviced. It also had a regular drain into the water heater vent drain.
Ask the manufacturers in your area about them. That is what all builders here seem to have been installing the last several years, with good results.
Yeah, I think a lot of crawlspace type furnaces are designed to be hung.
There are, of course, space heaters designed to be hung that are used in warehouses, etc, but I assume that a true furnace is desired here, to heat the house, not the garage.
One other point (to reiterate what was said earlier): Consider how the unit will be serviced, and provide appropriate ladder rests and maybe a sort of tool tray.
Thanks for the great responses, guys! I guess I should have been a bit more clear: I am not necessarily committed yet to an actual method of suspending the furnace, I was primarily asking about the idea of "placing" a furnace horizontally somewhere below the rafters.
From your suggestions, I am leaning towards a platform of some sort, probably with a ledger bolted to the studs at the wall, and a couple of threaded rods connecting the outer portion of the platform to the rafters. Not worried about the details right now, I'll see what the inspector says.
And I am aware of the drip pan drain that is supposed to be the tell-tale sign of a problem in the primary drain, I'll be sure to run it that way. Also aware of the requirement for all-metal ducting inside the garage, thanks for the reminder :).
Anyway, I think I have enough to go talk to my "final authority" on Monday and see what he thinks. I'll keep you posted!Leon
Make sure the wall and ceiling have at lest 5/8 drywall on them. Also you might consider putting a sheet of durarock on the deck between the plywood and the furnace for some fire resistance.
Check w/ your local fire marshall and/or bilding insp. If it is going to be in the garage, it must be at least 8ft. off the floor. Gasoline vapors and all that stuff. Like the other posts have said, there are units built to be suspended.
Check with your inspector about this:
Here, by code you need to have a specific sized access to the attic at no more than 20' from the furnace. Should not be a problem in the garage.
Many hang them in the attics above the garages, if that is the best place for them, they told me. No one mentioned IN the garage.