Hi all. I'm a fairly experienced DIY'er, but I'm not so well versed in HVAC. I have a 24x24 garage, 10' ceilings and a second story. I need to heat it. My plan was to buy a Hot Dawg, or similar ceiling mounted heater. However, I've been given a 100,000 btu natural gas forced air furnace. Problem is, since its not ceiling mount, it's a large foot print I don't want to give up in my garage. So I'm thinking maybe I could build a small shed off the back of my garage, and duct the cold air return and heat through the wall. My thinking is this arrangement also has the benefit of keeping the furnace and its flame out of the garage and away from any fumes. Any problems with this idea? Should I abandon the idea and stick witht the ceiling unit?
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Installing a gas furnace
- Thread starter Nitsuj
- Start date
Some furnaces can be laid on their side, then you could mount it on the ceiling just like a hotdawg heater. If you have more info on the furnace like model and serial numbers maybe some pictures I could tell you what would be involved with hanging it. Also it will still need some ductwork, not much but the fan does need some static pressure to work right.
Brand on the front is Tempstar, DC90 Ultra High Efficiency. Model number inside it is NTGM125EKA3. Serial num is L9835 16474. The year listed is 1993. It's pretty large to mount from my ceiling, might hang too low, but not out of the question. I'd still prefer to mount it in an attached shed if at all possible. I don't mind installing ducting, but I do have to vent it horizontally if I put it inside since there's a second story office above my garage. (Detached garage, btw)
The shed is fine if that's your preference, dc90 will have condensation to deal with and you have to keep it from freezing. IIRC the 1993 year would be refering to ashre regulations, the serial number indicates it was made in 1998. I think that furnace has punch through rivets that tend to fail, you will want to look closely at them. I will try to find a picture to post of what I'm talking about.
http://www.markbeiser.com/HVAC/WOS/goodmanhacks/gmprings3.jpg
http://www.awtreyhvac.com/images/he/he14.jpg
http://www.awtreyhvac.com/images/he/he09.jpg
My mobil makes posting pics difficult so here are some links to pictures of the rivets and an example of bad ones.
http://www.awtreyhvac.com/images/he/he14.jpg
http://www.awtreyhvac.com/images/he/he09.jpg
My mobil makes posting pics difficult so here are some links to pictures of the rivets and an example of bad ones.
dave67fd
Well-known member
It's probably been frozen, it's spent a few weeks of Pittsburgh winter in an unheated storage garage. Does that mean its probably been ruined?
No. The point is it requires a condensate drain to operate properly and if mounted outside during operation the condensate will/can freeze. You would need to have a plan to prevent that.
Also, seeing as this unit was given to you and is ~20yrs old are you confident it is in proper operating condition? People don't typically tear their furnaces out when there running well.
Have it proffesionally inspected before possibly wasting your time, money and health.
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10-4 on the inspection. The house was being torn down, the furnace was removed by a scrapper who was hired to clear the place out. I'm told it was working before removal. Look, if it's going to be a hassle, I'll just buy a ceiling mount unit like I originially planned. The reason I'm willing to look at the furnace is because it has the oomph to heat my upstairs office as well as the garage space, so I'd no longer have to use the wall mounted NG ventless heater I have up there now that only does a passable job.
Brand spanking new 80% furnaces are cheaper then you might think, if your not paying someone else to do the install. Put it on the second floor and run ducting to the garage space. You've already got a gas line up there, and you wouldn't have to build a shed for it.
BD1
Well-known member
I would go with the hot dawg. Your insurance may not cover a heater if it is not approved for garage use.
I am really skeptical of using really old (and it is) heating equipment. By the time you look at taking advantage of the free unit with associated costs, what if it gives up the ghost in a short time. I'd do a pressure test on the hx prior to installing. It is grossly oversized! Buy a good CO detector regardless of what you install!
James-W
Well-known member
Isn't 100,000 BTU's a bit big for that size space?
It is. But if its heating both the upstairs and down stairs, I figured it would be ok. I don't really understand what the drawbacks of a too big furnace are though. It just means it has to run less, right?
But, you guys are all making good sense. By the time a install a furnace in a shed, duct it and what not, the fact that its free wont matter.
But, you guys are all making good sense. By the time a install a furnace in a shed, duct it and what not, the fact that its free wont matter.