Does Size Matter?

[R6 Racer]

I have the chance to get either the 45000 or the 75000 Mr Heater Big Maxx for the same price $450.00. Here is where I need your help. which size is better for me? My garage is 730sq.ft. with 12 foot ceilings. It gets personal use only, a bit of light fab, basic car maintenance & winter parking for my better half.
Here's where I'm at now???
45000- longer burn of smaller unit or 75000- shorter burn larger unit
I'm thinking both would use about the same amount of gas but the fan would be on for a lot less time with the 75000 unit making it the cheaper to run.
Wouldn't the larger unit also last longer that way too? Being that it would get less hours use I thought I would get more years out of it.

Please help, my head hurts

Steve

PS: the 45000 has printed on the box that it will heat up to a 700sq.ft. space
I'm confused.

 

[HVAC Phil]

I would go with the 75k unit if you don't plan on keeping heat on all the time, it will recover faster. It will just "short" cycle more often.

 

[rwreuter]

I would go with the 75k unit if you don't plan on keeping heat on all the time, it will recover faster. It will just "short" cycle more often.

i sorta agree with him...

though it would be nice to know if you garage is insulated and how high the ceilings are.

my garage is 750 or so square feet (12' ceilings and insulated(living in kansas)) and i use a 50k-80k mr. heater convection propane heater (with 2 industrial ceiling fans) and it does a very good job. i would hate to use anything smaller.

 

[curiousB]

Also I see you are from Canada so if winters are -40 degrees then you probably want the extra kick of the 75k model. I get by fine with a 45K in a 3 car garage in IL. My garage is well insulated and has a warm room overhead of garage (part house of living space).

My 45k is fine but you have more severe weather and you didn't mention how insulated the space was.

Ideally a properly sized unit will be most efficient but the difference between one size and the next one up isn't going to change the fuel bill 100%. Frequent cycling is a little harder on the motors and relays but its not anything to get over analytical about.

 

[sarman47]

Steve

I just installed the 45,000 Big Maxx in a 22 x 22 with 9' ceilings. Worked great even before the attic was insulated. Now will the insulation in the attic the heater cycles less.

I also have the t stat set to heat 2 dregs above called for temp and cut in at 2 degs below so it cycles even less. As well with the fan running for a munite or 2 after the heater cuts out, the temp still rises.

I would recommend the 75,000 for your larger garage. I live in Ontario as well.

 

[R6 Racer]

It looks like the bigger unit will be the better one to go with. If anyone has any opinions to support the smaller unit, please post them!

sarman47 I like your thermostat idea, will be going with it, thanks.

I did say that my ceilings are 12' tall but I forgot to talk insulation. It's insulated to R20 in both walls & ceiling. It's an attached garage & shares 30 feet of wall with the house. It stays warmer than the outside without heat due to the insulation but I want to keep it above freezing.

Thanks for all the input so far.... keep it up guys!

Steve

 

[Relie]

Hi from western mass. Go to Northern Tool and check their prices. I bought the 45000 a couple of years ago for 399. and I think the price is close to that right now. By the way, my play pen (garage) is almost 1000 sq feet. (24x40) I don't heat it all the time, only when I work out there and it heats up in a matter of 10-15 min. If you can get the 75 for the same price as the 45, I say go for the bigger one. Otherwise, the 45 should be plenty warm enough.

Good luck with your project and stay warm.

Dave

 

[brokenknee]

Hi from western mass. Go to Northern Tool and check their prices. I bought the 45000 a couple of years ago for 399. and I think the price is close to that right now. By the way, my play pen (garage) is almost 1000 sq feet. (24x40) I don't heat it all the time, only when I work out there and it heats up in a matter of 10-15 min. If you can get the 75 for the same price as the 45, I say go for the bigger one. Otherwise, the 45 should be plenty warm enough.

Good luck with your project and stay warm.

Dave

469 for the 45k and 494 for the 75k at northern. Those are US prices, the Canadians have to pay more, just because.

http://www.northerntool.com/shop/tools/category_heaters-stoves-fireplaces+natural-gas

 

[Stuart in MN]

The only way to know what size heater needed is to perform a heat loss calculation. The best way would be to have a professional do it for you, but there are a number of free calculators online you can use yourself that will get you in the right ballpark.

 

[sarman47]

Steve

Here is a link to the t stat I use on my heater -

http://www.pro1iaq.com/distributor/thermostats_t771.html

Sounds like with the installation you have and your garage being attached you may be fine with the 45,000 Mr Heater.

Picked up my NG 1 at Lowes in Port Huron, Michigan for $377.00 US.