How to chose a heater size?

[Iroc-Z]

Looking at getting a Mr. Heater for my 25 by 25 garage in MN. They offer a 45K BTU and a 75K BTU. Price is close to the same. What one would be best for my garage. I know when I picked a furnace for my house bigger was not always better. Does this apply to a garage heater? The unit will be keeping the garage at 40 all winter and turned up when working out there. Thanks.

 

[Andamo]

I just had a Reznor installed in my 24 x 36 garage here in the Pittsburgh area. The fellow who I bought it from gave me the option of the 45,000 btu or the 60,000 btu. The price difference was only $15. He said the bigger heater will probably cycle more, but heat the area up quicker. Plus, I have a upstairs workshop and he said I could cut vents in the floor of the garage and heat the upstairs area as well. I only have a little insulation in the one corner downstairs and the rest is open studding. The gas company we have is VERY inexpensive, so that's why it's not insulated.

 

[ripsnortMN]

Im in MN as well. The colder part of MN. I have a 20'x22' garage and just installed a 45k modine hotdawg. The 45k was listed for a 2 to 2-1/2 stall garage. I barely have a two stall so it is a little big actually. A 75k for you might be inefficient in your garage for the size.

 

[Iroc-Z]

I am thinking the 45K is going to be the best option.

 

[ripsnortMN]

I am thinking the 45K is going to be the best option.

Thats what I was thinking. For your size garage the Modine website recommends the 45k. Even though its a different brand i would think it would be an accurate recommendation.

 

[TRDon]

I planned on running a 45K unit in my almmost 1000 sq ft garage in MN, Kev. I dont need heat all the time, but want it available. It will also make sure the heat exchanger gets hot enough to not condensate water and prolong the life that way. I dont need it to be 60 in my garage all the time, just above freezing most times and to take the chill off when I am out there.

 

[duaneb9729]

To keep your heater in good shape for many years, do one of two things, leave it on all the time, even if you set it at 38 degrees. Or if you have to shut it off and let the garage get good and cold, use something else first to take the chill out of the garage.

The heat exchangers will tear apart and not be covered by warranty, if you were to try and heat your garage up from a very cold temp.

As i am sure you know the more you do to insulate and seal up air leaks, the lower your heating bill.

I am a heating contractor, and if there is anyway i can be of help, feel free to pm me