Heating a 1000 Sq Ft Garage

We moved this summer, and the new place has a 1000 sq feet detached garage. It does not have gas run to it. I don’t want an electric heater. If I install a heater this year and want to run it on a 100 lb tank, I’m wondering how much it will use…obviously making some guesses. It’s well insulated according to our inspector. I’m thinking a Mr Heater 50,000 BTU garage heater. I’d keep it about 40 degrees until I want to come out and use it a time or two a week.

Is it a dumb thought to think I could use a 100 lb LP tank for this? How many would we guess I’d go through over the course of a “normal” winter?

TIA

A 100lb tank is 23 gallons and 1 gallons is ~91k btu. Of course your heater isn’t going to run full blast all the time but it will take a couple or few hours at full blast, at least, to heat up from cold.

I think a 420lb would be a better bet. That’s the biggest you can get without a distance from structure requirement and it’s cheaper to have someone come fill that than to come exchange 100lb tanks. If you were going to bring tanks to be filled yourself the math is different but 100lb are awkward as hell when full and you’ll need to transport them upright or a lot of places will refuse to fill it.

Have you thought about a wood stove? We have one in our house and from last year to this year we only used 200 gallons of lp.

It’s not terribly expensive to run a natural gas line from your house, assuming your house has service. I ran about 90′ out to a garage last fall for under 3 grand – all I did was rent a trencher (took me maybe 2 hours to dig the trench) and a pro did the rest. That price included the cost of the heater.

100 pound tank will not last very long. I’d go either 500 gallon tank or run natural gas if it is available.

I have a 28 x 32 detached and use 100 pound tanks right now. I have 2 and rotate them i keep my garage at 45 and am out there 1 maybe 2 nights a week and most weekends. When out there I run it about 62 I can get about 3 weeks per tank.

I’m with Slough, have you checked with a local HVAC guy to check the cost on running a gas line? My detached garage has in-floor heat, via an electric boiler. It was crazy expensive to use in the winter, so I switched to a gas unit heater. I believe it was about $500 to run the gas line inside my garage. I finished the remaining installation of the heater, running black pipe to the heater and exhaust.

fishinfreaks wrote:

We moved this summer, and the new place has a 1000 sq feet detached garage. It does not have gas run to it. I don’t want an electric heater. If I install a heater this year and want to run it on a 100 lb tank, I’m wondering how much it will use…obviously making some guesses. It’s well insulated according to our inspector. I’m thinking a Mr Heater 50,000 BTU garage heater. I’d keep it about 40 degrees until I want to come out and use it a time or two a week.

Is it a dumb thought to think I could use a 100 lb LP tank for this? How many would we guess I’d go through over the course of a “normal” winter?

TIA

My unattached garage is 32×40 or 1280sqft with a full length loft going the entire length of the garage with 10’ side walls. I keep my garage between 52-55 all winter and the loft is heated by the heat rising up the stairwell. I installed I believe it was either aa 40,000 or 50,000 BTU gas furnace. Most winters I average around 400 gallons of LP. I found it didn’t take really any more LP to leave it at 52 than to try and warm it up every time I was working in it and heat up the cold slab floor. Worked better when I bring in my tracked SXS to melt off the slush leaving at 52 degrees. I had them install a 500 gallon LP tank to run the heater which is located directly behind the garage, it’s nice not having to worry about the heat going off because of running out of LP.

Vented or non vented? Not sure they make a 50K unvented but curious, I know they make a 30k. I put a Mr Heater 85K vented unit heater in an in insulated single garage and only have it on if I’m working on something. I go thru just a touch I’ve one 100#er a year. Only complaint is that it’s pretty noisy when the fan is on. Remember a vented heater can be as low as 60% efficient.

Another issue with the 100# tank is that it will run at a lower pressure making it run more sooty vs that 500# tank. The 500 will keep the pressure up and allow the heater to run more efficiently. We installed gas fireplaces in all sorts of cottages and ran into the 100# soot issues frequently.

If you have access to natural gas, go that way as it’s way more efficient, burns way cleaner, could be cheaper and should never run out…

Mark

Is this a humble brag? For example:

“I have a 13 inch member and cant find jeans that fit, any suggestions”

Im just jealous of your garage!

Depends on how it was insulated.
I built a 26 x 40 (1040 sq ft) last January. Spay foamed the entire bldg.
I can heat it all winter with a bic lighter. Ok maybe 2, but insulation is key.

Nobody mentioned 250 gallon. That is a very popular size for cabins. That’s what we have at our cabin and it lasts a long time. Heat is on all winter and we are there most weekends. I think we need it topped off once per winter.

Nothing wrong with a 250 gallon tank, but filled up (80%) is only 200 gallons. But if you use between 200-350 gallons of propane, you could get by on filling once a year in the summer with a 500# tank when prices are usually lowest. If you prebuy your propane a 250 gallon tank would be just fine if you used more than 200gallons a winter. I originally had a 250 gallon tank but swapped it out for a 500 gallon tank so when I filled it in the summer I could pretty much make it through the winter.

“well insulated” is pretty vague. What’s well insulated to some is not to others. Insulation is also only as good as its installation to eliminate air leaks, moisture, etc.

A detached garage that size could absolutely eat propane or it could be quite efficent with the right insulation, doors, door jambs, and rarely being opened.

I’d go bigger on the tank if it’s feasible. There’s no way I’d mess around with a 100# tank regardless of efficency for a 3+ car garage that’s detached.

buckybadger wrote:

“well insulated” is pretty vague. What’s well insulated to some is not to others. Insulation is also only as good as its installation to eliminate air leaks, moisture, etc.

A detached garage that size could absolutely eat propane or it could be quite efficent with the right insulation, doors, door jambs, and rarely being opened.

I’d go bigger on the tank if it’s feasible. There’s no way I’d mess around with a 100# tank regardless of efficency for a 3+ car garage that’s detached.

I agree . I am sitting on a 32×50 detached . Infloor heat , not hooked up . Debating of adding a Modine or doing the infloor . Cost wise the Modine is cheaper , prices to do the infloor have sky rocketed

Don Meier wrote:

I agree . I am sitting on a 32×50 detached . Infloor heat , not hooked up . Debating of adding a Modine or doing the infloor . Cost wise the Modine is cheaper , prices to do the infloor have sky rocketed

Infloor heat is nice, but I would think it would only work well if you kept your garage at a certain temp all year. Trying to raise the temp for a short period of time like a day, the Modine would be the better option, but that is just a guess.

DaveB wrote:

Is this a humble brag? For example:

“I have a 13 inch member and cant find jeans that fit, any suggestions”

Im just jealous of your garage!

I’ve got a 40x80x14′ shop, is that like a 16″ pecker??

Last winter was obviously very mild, but I only went through one 500 gallon tank to keep it at 50° (better than I thought it was going to be)

I’m hoping in a normal winter it will be in that 750 gallon or less mark?

Damn the heated part of my garage is only 24×24 I must almost have an innie.

My shop is about the same size, I believe my heater is a 50k. Due to location and setback requirements on bigger tanks I can only get up to 125 gallon tanks so i have 2 of those. I keep the thermostat at 45 degrees unless I need it turned up for some reason and those two tanks last the season for me.

Which reminds me, I need to get them filled.