Big Maxx or Hot Dawg?

[Gunnert]

Finally had spray foam insulation shot in the ceiling and I'm now ready for heater. Detached garage interior is 33'x28'. Ceiling is open rafters and pretty high, I have a two post lift. If I have my numbers right I need about 35k btu to heat (which means I need need 45k btu unit (input 45K/output 35k).

Heating: The Big Maxx and Hot Dawg seem very similar except the BM is about 20% less $. But, the BM specs say it heats only up to 700 sqft... What gives, is there a lot, if any, difference in performance of these two units?

 

[24ModelTFord]

I can't comment on the Hot Dawg, but I just got my Big Maxx 50K heater set up and running yesterday. Nice and quiet, works very well. My garage isn't as nearly as big as yours, (about 500 sq ft), but judging on the way mine runs, it wouldn't have any problems keeping your garage warm.

 

[dave67fd]

Both heaters are similar in design and performance. Modine has been around along time and are good heaters. I also have the Big Maxx and very happy with it. With your open ceilings you really will need to install some ceiling fans as all that heat will sit at ceiling level.
I think your 35k numbers are abit undersized. Will the 45k unit heat it properly? Maybe. I would consider the new 80k BTU unit. I have the 75K unit in my 28 x 38 with 10.5' ceiling.

 

[Steevo]

My shop is 24x40, with the finished interior being 23x39, or 897 sq ft.
I have 12' ceilings, 2x6 walls with R21 insulation and R60 blown-in on top of the ceiling.
My shop is in Eastern Idaho.

I have the MrHeater 75KBTU unit, and it does an excellent job of keeping the place warm.
Based on my 1 year of experience with this setup, I think I could have gone with the 45KBTU model and got away with it.

You have only 27 more square feet than I, but I do not know how high your ceiling is, what R-value insulation you have in your walls or in the ceiling. If your peak is 16 feet, there is a lot more air space inside your shop than mine. If your walls are 2x4, there is less insulation in them than mine. If your spray foam is less than R60, than you have less ceiling insulation, and that is the most critical of all, since it makes the most difference in how well the building will retain or lose heat.

We also don't know what your climate is, because you have no location in your profile. You could be in West Moose Turd, Maine, which would be a lot different than where I am in terms of how cold it gets.

 

[ketas47]

Both good units, hot dawg according to some maybe a little better but also is usually more expensive than big maxx. I have a friend who has the 75000 big maxx in a garage your size and loves it. He had a 35000 unit before and on a cold WIS week it barely kept up. Depends where you live , if a northern climate I would go with the bigger unit for sure( not alot more money) Just my 2 cents!!

 

[Gunnert]

I updated signature....

The Garage Heating Calculator calls for 36,000 BTU...

 

[ChtnDth]

How tall are your ceilings 24modeltford ?

 

[24ModelTFord]

How tall are your ceilings 24modeltford ?

My ceilings are finished at 9 feet. The garage is insulated, but not sealed up tight.

I missed the part in the OP about the open ceiling......

 

[rare_earth]

Did any of you folks insulate under the slab, which I think would reduce the heating load a fair amount? If not, would you recommend doing so if you had it to do over. Dave

 

[Chetter]

Yes I would after what I learned from doing that in the crawl space that I put in when I built the addition for the wife's kitchen, it helps, jmo.

 

[dandan111]

My local heating and plumbing contractor likes the hot dawg. I had a farenheat electric installed but they were pushing me towards the hot dawg for gas.

 

[CNGsaves]

Top three vendors for hanging garage heaters are Reznor, Sterling and Modine.

Sterlings sell under the name of Garage Guy - - -ie GG45, GG75, etc. Modine garage heaters are called the Hot Dawg (ie horizontal heater).

Mr Heater (Big Maxx) is a lesser brand than the above.

If you try to buy a used one, be aware that SC version of Reznor is SEPERATED COMBUSTION which has double the flue costs since both intake and exhaust air need connected. These COST MORE, but would be appropriate if you were to be doing lot of painting or something generating fumes as heater wouldn't be trying to burn that air.

 

[Shocker]

My 45k Mr Heater unit is heating up my 764 sqft shop no problemo. Even better when I added the 2 ceiling fans.