Need Advice On Garage Heater

[msmit62]

We moved about five years ago and I'm finally getting ready to hook up the floor mounted cabinet-style heater (natural gas) in my garage that I had at my old garage so I can have a warm place to work in the winter. There is no chimney in the new garage so I need to have a hole cut in the roof. Before I proceed, I just wanted to ask all of you if I would be better off purchasing a hanging furnace and venting out the side of the garage rather than cutting a hole in the ceiling and roof. I've always believed the old saying that says something like "never cut a hole in the roof if you don't have to". The hanging furnace is anywhere from $500-$1000 and, according to my heating guy, not that much more efficient than my old cabinet-style heater. The hanging furnace has a forced exhaust so it can be vented sideways, whereas mine vents naturally, so it has to have a vertical chimney. I think I'm better off sticking with what I have, but I just wanted to see if any of you had strong feelings against adding the chimney hole. A few other points that might be important: the work would be done by a local professional roofer (recommended by a builder that I trust), the garage roof is only 4 years old, the heater is old but rock-solid (the burner will never rot away). Thanks in advance for any advice.

 

[PoorUB]

Properly done I have zero issues with venting through the roof. "Properly done" is the hard part!

 

[jlv03]

Floor mounted would put the heat where you appreciate it the most. The hanging furnaces have the advantage in that they are up high and give you more floor space.

 

[finn]

Hanging frees up floor space. That made it a no brainer for me.

 

[msmit62]

PoorUB, what defines "properly done" other than no leaks? Is there a preferred material for parts? The parts I purchased from the heating company (I could return them if I change my mind) were galvanized and supposed to be the correct gage for this application.

finn, true...hanging does indeed free up floor space.

 

[Gizzi]

PoorUB, what defines "properly done" other than no leaks? Is there a preferred material for parts? The parts I purchased from the heating company (I could return them if I change my mind) were galvanized and supposed to be the correct gage for this application.

finn, true...hanging does indeed free up floor space.

Honestly, if you have no clue about proper materials, clearances, and practices, you might be better off having a licensed HVAC guy do the work. I'm not trying to be a *****, but giving advice over the internet doesn't typically cut it in terms of safety. You are dealing with situations involving gas and venting, both of which if done incorrectly could injure, damage property, or kill someone.

 

[msmit62]

Gizzi, no worries and no offense taken. If you read my initial post you'll see I was planning on having a professional do the installation.

 

[Bruce Amacker]

Hanging forced air, probably 8 feet up by code if there are cars in the garage. Anything lower is a fire risk if the cars leak fuel and would cause issues with your insurance. I have two power vent through the wall and one through the roof, non-power. Either is fine.

 

[Showkey]

Hanging furnace there maybe a head knock clearance in some areas.

The ignition source clearance is 18”.

Appliances having an
ignition source shall be elevated such that the source of ignition
is not less than 18 inches (457 mm) above the floor in garages.
For the purpose of this section, rooms or spaces that are not part
of the living space of a dwelling unit and that communicate
with a private garage through openings shall be considered to
be part of the garage.

 

[PoorUB]

PoorUB, what defines "properly done" other than no leaks? Is there a preferred material for parts? The parts I purchased from the heating company (I could return them if I change my mind) were galvanized and supposed to be the correct gage for this application.

Properly laying he shingles over and then under the sheet metal flashing. I have seen more than one guy that "knew" what he was doing screw it up!

 

[HoosierBuddy]

As pointed out above, for safety reasons (as well as code compliance) you need to get this "cabinet" up off the floor anyway.

They make high efficiency hanging heaters if that's what you're looking for. They vent with PVC sideways just like any other fully condensing appliance. I've used the Modine effinity units at work and they are essentially problem free.

But if it was me first I would decide if I wanted to use my existing heater. To decide that I'd look at the age and condition of the unit and how much room it would take up and where. If all that looks OK....I'd use it. If the unit is on it's last legs or that square footage on the floor is really needed for something else....then I'd go with the hanging heater.

Phil

 

[PoorUB]

The Modine Infinity heaters are good units, but twice the price! One needs to calculate their possible savings. Also the smallest Infinity is 55,000 BTU so that puts it out size range for the home garage or smaller shop. Also, dealing with condensate can be an issue. Plus you need to let it run. You can not shut off the heat and walk out a few weeks later and fire up the heat as all you condensate lines will be frozen and probably broken.
It is a good unit, but not the unit for everyone.

 

[msmit62]

Properly laying he shingles over and then under the sheet metal flashing. I have seen more than one guy that "knew" what he was doing screw it up!

PoorUB, I'll ask the roofer about this. Since we bought this house (it was an old farm house that was solid but needed a lot of TLC) we've developed a good relationship with a very reputable local builder who did a lot of the updates for us. The roofer I'll be using is the same one they use on their projects. In fact, it's probably the same individual. So I should be in good hands, but just to be safe I'll still ask him about the "shingles over and under" that you mentioned. Thank-you for that information.

HoosierBuddy, the furnace is old but it's solid and safe as long as the user understands how to use a pilot light. I had a technician disassemble it a few years back before I first used it and we discovered that the burner is rock solid...made of thick material so it'll never rot away. I always run a CO detector nearby as a precaution. Eventually I'm going to build a bigger workshop so I think I'm ok with losing a little floor space for now.

At this point I think I'm leaning towards having the hole cut in the roof and using my existing heater so I can put that $ towards other house projects.

 

[msmit62]

...but please continue to make suggestions on how to "do it right" as I'll be keeping an eye on this post.

 

[N969DP]

I’m hanging a normal 80% house style furnace with 10+ feet of ductwork from the ceiling in my garage. Mainly for a quieter heat source than a unit heater, but I can see adding A/C in the future as a real possibility.

It was a real pain to source good quality venting parts. Nobody wants to sell to the public or they just say to get **** from Menards/Home Depot. I’d recommend just hiring an hvac company to do it for you if it’s in budget.

 

[nadogail]

I have an electric 5KW Fan Forced Heater hung from the overhead in both my garage and workshop. Being in a very mild climate, it does not get much use. The Solar panels keep my electric bills down.

 

[Improved700]

I’m hanging a normal 80% house style furnace with 10+ feet of ductwork from the ceiling in my garage. Mainly for a quieter heat source than a unit heater, but I can see adding A/C in the future as a real possibility.

It was a real pain to source good quality venting parts. Nobody wants to sell to the public or they just say to get **** from Menards/Home Depot. I’d recommend just hiring an hvac company to do it for you if it’s in budget.

I did the same thing as you. I was able to run ducts on both long dimensions of my shop to distribute the heat. Ran the exhaust out the side of the building.

Very happy with the install, and love the nice warm heat.
26 X 36 with 10 foot side walls, fully insulated 2 X 6 walls covered with 5/8" plywood.
Natural Gas, Wisconsin.
Keep the heat at 65-70 all winter long.
Add's maybe 30 bucks a month TOPS to my energy bill

Would never have a shop without a decent heat source again.

 

[Showkey]

1000 sqft garage/shop duct work might be nice……but…….there is no need. Hanging heater in one corner will easy circulate the heat.…… At a much lower cost. “Typical hanging garage heater” are not meant to be ducted.

 

[Improved700]

1000 sqft garage/shop duct work might be nice……but…….there is no need. Hanging heater in one corner will easy circulate the heat.…… At a much lower cost. “Typical hanging garage heater” are not meant to be ducted.

Agree that not totally necessary.
However, in my situation, my building is actually 64 feet long.
I walled off the 36 foot section and plan to finish the "cold" side
with ceiling and wall insulation and plywood.
Then I could extend the duct work to evenly distribute the heat.

 

[Showkey]

Agree that not totally necessary.
However, in my situation, my building is actually 64 feet long.
I walled off the 36 foot section and plan to finish the "cold" side
with ceiling and wall insulation and plywood.
Then I could extend the duct work to evenly distribute the heat.

Yes…..agree that makes a HUGE a difference .

 

[Steve in UT]

I bought an after market power vent for a non power vented heater and ran it through the wall. Used it for years, trouble free. You might look into that option!

 

[banjopete]

An updated hanging unit can be moved once more to the new building if you go that way eventually and the side vent/horizontal vent options eliminate the need to cut into your 4 year old roof. If you read through the threads in here for garage heaters most people mainly love having heat at all, the next ones love their hanging units for all the mentioned reasons. My only regret with mine is I didn't do it sooner. If you go vertical for the vent the roof hole and flashing work is plain everyday work for a roofer, I wouldn't give it a second thought if you trust the guy's previous work. Good luck.

 

[msmit62]

Update: I went with the traditional through-the-roof chimney installed by the well-recommended local roofer and it's all done. Now I just have to get the gas line hooked up and then I can work this winter on finishing the rest of the garage (wiring, insulation and plywood on the walls and ceiling). Thank-you to all of you for your responses. ps: Sorry for my late response. For some reason, I'm not getting emails that notify me when a response was added. It appears that I'm subscribed to this thread...