Heater placement

[signcrafter]

Garage is basically two 2 car garages, all one open space. There are two 16' and one 9' overheads and a 5' patio slider. Then 2 man doors going outside and one more going into house. The smaller of the two car sections has taller ceilings, around 10' tall and the larger section is around 8' tall. All gas and electrical is going to come from house were it says attached house. All doors are insulated and everything else is insulated except the ceiling of the smaller section but that will be insulated at the time I install the heater.

Going with a 75,000ish btu natural gas ceiling heater like reznor. Heater will keep things at 45 or so in winter to keep things from freezing and then kicked up when I'm out there working.

Wondering about location of heater? Would middle of the two sections be best? Or in one corner? I'm thinking the middle would be best so it can be close to the storage area and keep things from freezing but still be close to the working area to warm that up quick when needed. But I dont know much about this stuff. I do have a heavy duty wall fan I can use to help direct heat as needed but ideally that would be only when heating up the working area when needed, not to run all the time. I also use it in the summer to get the humid air circulating so again would be ideal to have by the working area. Not even sure if fan is relevant but wanted to throw it out there.

Also, where would be the best place to put thermostat? Ideally that would be by the house so I can just reach out and turn it on or off. But again dont know much about this and dont know how that would affect the heat cycles and how that would keep the garage as consistent of a temp as possible when just keeping it above freezing. Thanks for any advice.

 

[Bill Bowman]

I'm certainly not an HVAC expert. My shop is just a bit longer than yours (62' long). My heater is mounted, to blow heated air from one corner to the other. Kind of like having it on the house end, and opposite your 16' door. Pointing toward your smaller area.

My shop warms up very fast, plus it's not attached to my house, so I don't have a warm house against one wall. I have never thought of an extra fan being needed. For thermostat, you could probably mount it like you mentioned, as long as the furnace is not blowing air directly at it.

 

[PoorUB]

If the one area is storage I wouldn't worry about it being a bit cooler. I think I would put the heater in the corner of the larger area, blowing towards the overhead door and an angle, towards to opposite corner of the large area.

Where are you located? California heat requirements are different than here in ND.
All reasonably insulated?

IMO, 75,000 BTU is a bit large, 60,000 BTU would still be a bit large and what I would recommend. I think it would heat with a bit less that 40,000 BTU so actually a 50,000 BTU input. It would heat just fine here in ND. Anywhere else the 60,000 is too much. I have put 30,000 BTU heaters in 1,000 sqft garages.

Mount the thermostat on the house wall as it is heated as will give a better indication of the temps in the garage. Nearer to the heater so it reads cooler air coming back to the heater. You don't show the door to the house, but near that door would be ok, as long as the heater is not blowing toward it.

If you mount the thermostat on an exterior wall the cooler wall will give a false reading. Often with a building with no walls adjoining another structure I would mount the thermostat off the wall a bit on a bracket so air can flow behind it.

 

[signcrafter]

Location is wisconsin. I think you did recommend a 60 in my other thread. I havent ordered the heater yet. Just trying to get all the homework done so I wont have any questions once I start putting the puzzle together. Most of the garage is insulated. The storage area ceiling is not insulated yet but that will get done before or same time as I do the heater.

 

[PoorUB]

Sorry if I answered before, I don't keep up on who starts the threads! Hopefully I gave the same information!

 

[D45]

Look at the fan size and heat throw specs also, could be useful

HD 45K
10" fan
27' heat throw

HD 75k
14" fan
38' heat throw

 

[signcrafter]

Sorry if I answered before, I don't keep up on who starts the threads! Hopefully I gave the same information!

If I remember right you said 60 but not bigger then 75. I havent ordered one yet so just threw 75 out there as a starting point. Thanks

 

[PoorUB]

Look at the fan size and heat throw specs also, could be useful

HD 45K
10" fan
27' heat throw

HD 75k
14" fan
38' heat throw

You don't size heating equipment by the fan throw!

Even the smaller heater would move enough air to somewhat even out the temperatures. The air just doesn't stop moving at 27 feet.

 

[D45]

"Could be useful"

 

[PoorUB]

"Could be useful"

Not really. For what purpose?
Like I said, you don't size for air throw, so what difference does it make? It might be interesting information, but other than that it serves no purpose in sizing equipment.

I sold and installed equipment for over twenty years and air throw never once came into the picture other than a curiosity. I still sized the equipment by BTU.

 

[D45]

Ok

 

[DaveMcLain]

What do they mean by "heat throw" anyway? In my 36x48 building I have an HD 75 mounted to the 10ft ceiling in a corner. When it blows it easily throws heat to the opposite corner and that's 60ft away.

 

[PoorUB]

What do they mean by "heat throw" anyway? In my 36x48 building I have an HD 75 mounted to the 10ft ceiling in a corner. When it blows it easily throws heat to the opposite corner and that's 60ft away.

It means just what it sounds like, but like you found it does much better than advertised. Like I mentioned earlier, the air doesn't stop moving at the end of the heat throw. It keeps it stirred up and will heat much farther.

 

[gmcgeo]

Heat throw is the amount of air that is moved by the fan across the room. Air circulation is controlled by the throw value.

Obviously if you put in a vent free heater with no fan, it would have no "heat throw"

Manufactures will add the spec of Heat throw, and or CFM the fan can produce.

When sizing a building for heat, i have never factored in the heat throw to size the heater.