Location for ceiling mount heater

[danielcooper9]

I'm trying to decide where I will mount a ceiling mount propane heater (like Reznor). Space is a 30 x 30 garage with 10' walls that angle up to about a 12' ceiling (the trusses are angled towards the top to give me extra clearance for a lift). The garage doors (two 9' wide) are located the gable end of the garage.

I was thinking of mounting the heater on the gable wall side (of the ceiling) opposite the garage doors. So this would put the heater pointed towards the garage door openings. two reasons for this; 1) I can easily put a horizontal vent out the gable wall as this side points towards a wooded area and not visible, 2) I understand you are supposed to locate the heater to be directed towards cold air entry areas (like garage doors).

Does this make sense? Different suggestion for location? Planning to do a 75K BTU power vent model

Thanks

 

[finn]

75 k is too large for only a 30'x30' garage.

I located mine near the door, aimed into the 32'x75' room so I won't be blasting air out the door when I open it.

 

[Milton Shaw]

Don't put it where the hot air would cook the paint/bumper on a car left on the lift for an hour. You could have melted mess on your hands when you come back from lunch.

 

[GreyOwl]

Don't put it where the hot air would cook the paint/bumper on a car left on the lift for an hour. You could have melted mess on your hands when you come back from lunch.

A pic of this would be great as well as the rest of the story!!

 

[yeldogt]

You want to get the smallest heater you can that will heat the space the way you want to use it. In other words -- if you plan on keeping a minimum temp and only want to raise it when you work out there you will not need anything like a 75k heater.

I do my entire 1700sf well insulated studio space with less than 1/2 of what you are proposing. I keep it at 65. Garage space is most comfortable when the heater is running -- the warm air is being circulated. When the heater turns off the space will start to cool and be drafty -- how fast and how much depends on the space. With a big heater is -- on off of off .. you want lower output for longer periods.

Propane can be expensive (cheap currently) -- and most heaters are 80% ... what's your electric rate? In my old space I had both propane and electric -- the propane kept the space warmish. Only used the space on the weekends ... I would turn up the propane heater and flip on the electric if I wanted to work when I arrived on a Friday -- the electric was down low and warmed the floor. I would only need it for an hour or so -- otherwise the propane 38k 80% was all I needed.

 

[danielcooper9]

Here are a couple of photo's. The inside picture is standing at the gable wall that I was thinking of putting the heater. I would point directly at the garage opening but as I read Reznor's site, that is also what the suggest (at least the way I read it). I guess the idea is that it helps counteract the cold air trying to come into the heated space.
In any case, I also like this location to mount the heater as the vent would be less obvious. If I put it at the front of the garage, I would need to do a roof vent (which is doable as well).

Regarding size, I was just using the size suggested by an HVAC quote that I received. This is a detached garage and I would normally plan to keep it at 50 or so but would want to warm it up to 65 fairly quickly when I want to work.

 

[yeldogt]

Nice building -- what are you going to use it for? Will it always have two cars?

Remember many of the "garage" style heaters are not sealed combustion -- the reason most are mounted high up is for space .. there is no place to have them down low. Ideally you want the heat at the floor. Make sure to get good insulated garage doors that seal well -- no heater is going to make that area comfortable if it's leaking a lot.

I always use a sealed combustion fan forced wall unit at the floor (few inches above)-- they use a small vent directly out the wall. My current space uses the Empire .... they sell a 40k now .. I believe mine is a 38k. Properly insulated and tight the space will get warm -- it's all a matter of leaking at the doors.

What's you electric rate ? Thinking of AC?

 

[Dagny]

If your going to keep it heated look at a 90 percent furnace. More eff.

 

[yeldogt]

If your going to keep it heated look at a 90 percent furnace. More eff.

The only fear would be if the building dropped under 32 .. when you get above 85% they condense and you have water ... they are also more complicated.

I'm all for efficiencies -- but in some places the tradeoff is not worth it. You get more comfort with modulation .. that worth paying for. Comfort is worth paying for --- VS AC units are with paying for because they provide more comfort. I actually used a convention Buderus boiler in my last project with radiant -- the unit was cheaper and they run forever. The 14% gas savings over 20 years was never going to come close to the difference on that project -- I gained no comfort benefit.

 

[danielcooper9]

This garage will have one car all the time. I plan to keep it at 50 degrees during winter and then heat it up to room temp when I want to work in it (mostly weekends and maybe some weeknights). As far as heater sizing, part of the oversize was to accommodate not keeping it at a constant temp so ramp up time doesn't take a long time. Also the ceiling where it angles up in the picture is upwards of 13 feet or 14 feet high. So it's a bigger space than just a 900 sq ft area.

My main question is really on placement of this type of heater in the garage. Reznor says the heater should ideally be aimed along an exposed wall. Not knowing anything about airflow for this type of heater, I would have put it in the center of the gable wall opposite the garage doors pointing towards the center of the garage. If I'm reading Reznors design correctly, it would suggest putting it more in the corner blowing along a wall (I guess the assumption is that the walls then help funnel the airflow to get more distance of airflow? Anyway, for those who have ceiling mount heaters, where in the garage do you have it hung?

 

[Shop Specialties]

I would put it in the center of the back wall pointed towards the garage doors. BTU wise I would not go over 60K and depending how well insulated possibly 45k will do the job.

 

[yeldogt]

I normally see them in a back corner -- pointed out so the discharge covers the whole garage on a diagonal. Up high they allow for head room and it's normally better to have the flue in the back of a building.

I find 50 too cold -- remember, everything in the building is cold. With too big a heater -- it will cycle off before everything warms up ... heat the air and shut off. I do twice the space with 1/2 the BTU's .. my space is well insulated with insulated carriage doors ... high ceilings.

 

[D45]

IMHO, a 45k will not do the job.............definitely go more, like a 60k

Put it in the center back wall

Do all the work yourself, the install and vent work is VERY easy........even for a DIYer

 

[yeldogt]

Just called my brother -- his garage is 30x50 12' ceiling with an 80% 60k ... and he is in NH.

It's very well insulated .. but he is always opening the doors.

He maintains the space at a bit under 60 ... so he has 1500sf feet .. you have 900sf.

 

[Falcon67]

IMHO, a 45k will not do the job.............definitely go more, like a 60k

Put it in the center back wall

Do all the work yourself, the install and vent work is VERY easy........even for a DIYer

I have 960 sq/ft, need to heat 680 section if it's cold. The heater is electric, 17K BTU. If I run it too long, have to open the doors. IMHO 45K in a 30x30 is plenty.

 

[marinusdees]

I normally see them in a back corner -- pointed out so the discharge covers the whole garage on a diagonal. Up high they allow for head room and it's normally better to have the flue in the back of a building.

I find 50 too cold -- remember, everything in the building is cold. With too big a heater -- it will cycle off before everything warms up ... heat the air and shut off. I do twice the space with 1/2 the BTU's .. my space is well insulated with insulated carriage doors ... high ceilings.

Mine is in the back corner of a 40' x 40' space with a 12' ceiling. Pointed on the diagonal towards the opposite corner. It is a 150,000 BTU hangar heater I picked up new surplus 27 years ago. I keep it minimum 50 degrees when I'm not in there, I don't want anything in the building to freeze. It may be oversize, but I don't care. The price was right and it warms up the place in 10 minutes or less, although our climate is relatively mild. One wall is 3 10' x 10' uninsulated doors, aluminum frames, mostly single pane glass. Commercial service station doors, two used and one new. The price was right, and I like the light. I bought and cut plastic fluorescent light diffusers to fit inside the glass and secured them with silicone caulking beads. That way, no one can see in, and I have daylight. The remaining walls are 6" thick and have 6" of fiberglass insulation. The ceiling is 6" or more of blown in fiberglass. I am not a fanatic for having the doors seal tight. They are what they are. This building has served me well for 27 years, and I'm about done with it. I have had to adjust the pilot sparker a couple of times and once replaced the entire gas control valve. Shopping on line made that a lot less painful than buying from Johnstone Supply. Hope this helps.

 

[jkuro]

If this is a new build, why not get a gas fired 90% forced air furnace with some duct work.

 

[D45]

Maybe I missed it, but where is the OP located?

 

[danielcooper9]

Thanks everyone for their input. I'm in Baltimore so winters aren't usually harsh. I will probably put a 60k unit in and install it on the back gable wall in the center. I'm just going to use a standard power vent unit (not sealed combustion chamber) as I don't expect there to be a lot of fumes or dust that might be an explosion concern.

Anyone use those thermostats that can be controlled wirelessly for this type of unit? I've never really looked into those thermostats but I assume they just establish a wifi connection (which I will have cable and wifi in the garage) and hen you control it by apps on your phone or computer.

 

[D45]

I think you will be much more happy with the 60K, good call

I just use a cheap ole' $20 'low temp' garage stat with my 45k