Question about how long a propane tank should last...

[mpls|cafe|racer]

I have a 2 car garage. If I remember correctly it's 24 wide, 20 tall and 8 feet at the ceiling.

There is NO insulation in the garage at all.

I have a 140K BTU Reznor heater that I can set up.

I was thinking of buying a propane tank and getting this thing into the garage.

I am in Duluth, MN. In the dead of winter we're seeing -30 sometimes, a decent amount below 0 most of the time tho.

I would just like to get the garage up to the mid 50's/lower 60's so I can work out there in a hoodie.

Wondering what size propane cylinder you guys would recommend, and how often you think I should replace it?

I won't be out there every single night or anything this winter, but probably 4-5 nights a week for a few 3 or 4 hours.

Would it be worth putting up some insulation and vapor barriers?

(Asking because I rent the home and can't bring the insulation with me, so it might be a bit of a lost investment. I CAN take the heater and my tank though.)

Thanks gents!

 

[slip knot]

I'm in a lot warmer clime but I run a 30K btu Dearborn on medium heat and can get 10-12 hours on the small propane bottle. I would think your 140K would require a much bigger bottle to feed it.

 

[rburke65]

How long do you plan to rent might be a factor to consider! Your going to be there for the next 30 years renting, then go buy the insulation. Get some 4'x8' panel Inslultion and nail it up on the ceiling. I think propane is going to get expressive in your cold location.

 

[mpls|cafe|racer]

We're gonna be here until next fall, so just for this winter.

We need to move after that because we're having another kid in March and will need a 3 bedroom after that.

 

[jhelrey]

Then cheap as possible... what you save on materials, you can spend on LP

 

[boo coo tracks]

Where in the garage do you spend ? If it's around just your work bench, you just put a few sheets and hang some 4 mil plastic from ceiling. Screw in 4x8 sheets in ceiling. When you leave, just take it down & sell it. A small space would not require a large heater.
Tracks

 

[mpls|cafe|racer]

Where in the garage do you spend ? If it's around just your work bench, you just put a few sheets and hang some 4 mil plastic from ceiling. Screw in 4x8 sheets in ceiling. When you leave, just take it down & sell it. A small space would not require a large heater.
Tracks

I do welding and fabrication, so I'm all over the garage usually.

 

[dwp99]

I would think something like this should last you through the winter

 

[Jackfre]

There are 21,000 btu in a lb of propane. 92,000 in a gallon. You are going to run about 7 lbs/hr. how big is the tank? How many hours are you going to be out there? Look at the cost of your lp and maybe, insulated you can cut your load 2-3 lbs per hr vs the cost and hassle of insulating.

 

[Falcon67]

You'd get maybe 4~4.5 hours out of a 30 lb tank, so I think you'd have to have a big, heavy 100 lb tank to make it worth while. Personally - sell it, insulate and get something in the 30K ~ 45K BTU range because that's all you need for a space that size. I kept my old 24x20x8 shop nice and warm with a 5000w (17,500 btu) electric. It was insulated R13 on all edges. We don't get minus anything around here, so 45K btu might be more what you would need.

 

[mpls|cafe|racer]

There are 21,000 btu in a lb of propane. 92,000 in a gallon. You are going to run about 7 lbs/hr. how big is the tank? How many hours are you going to be out there? Look at the cost of your lp and maybe, insulated you can cut your load 2-3 lbs per hr vs the cost and hassle of insulating.

Wouldn't that be if the heater was running constantly though?

~20K BTU/LB. x 7 LB = ~140K BTU (heater output).

I'll be out there for 3-4 hours a night, 4-5 nights a week. So figure 20 hours a week max.

I was looking last night and thinking it might be fast and easy (and comparatively affordable) to just put up polystyrene foam boards in the garage and on the ceiling, then do lauan board over that inside. It's not fiber batts with drywall or anything, but it would go up real fast and be a quick weekend job.

If I owned the place there'd be no doubt, I'd just insulate it right and be done.

Wouldn't some insulation just mean the thing would run less? I'd assume 140K BTU output would just mean that it would get the garage up to temp faster than a 45K BTU unit. Am I mistaken on that? I don't know much about heaters clearly. I melt metal for a living. This HVAC stuff is greek to me.

 

[geoffg]

Be careful that whatever you put up, there's reasonable fire protection. Some insulations seem to burn more readily than others, and if you're welding you will throw sparks.

If you can locate a woodstove for cheap, you might be able to get the wood for free...

 

[mpls|cafe|racer]

Be careful that whatever you put up, there's reasonable fire protection. Some insulations seem to burn more readily than others, and if you're welding you will throw sparks.

If you can locate a woodstove for cheap, you might be able to get the wood for free...

Good reminder in general. (I tig weld tho. So no sparks.)

I can't do a wood stove. Landlord would kill me. It'd cancel his home owners insurance right quick.

 

[Jackfre]

Wouldn't that be if the heater was running constantly though?

~20K BTU/LB. x 7 LB = ~140K BTU (heater output).

I'll be out there for 3-4 hours a night, 4-5 nights a week. So figure 20 hours a week max.

I was looking last night and thinking it might be fast and easy (and comparatively affordable) to just put up polystyrene foam boards in the garage and on the ceiling, then do lauan board over that inside. It's not fiber batts with drywall or anything, but it would go up real fast and be a quick weekend job.

If I owned the place there'd be no doubt, I'd just insulate it right and be done.

Wouldn't some insulation just mean the thing would run less? I'd assume 140K BTU output would just mean that it would get the garage up to temp faster than a 45K BTU unit. Am I mistaken on that? I don't know much about heaters clearly. I melt metal for a living. This HVAC stuff is greek to me.

Yes, I assumed worst case scenario...but then again, you are in Duluth. You can push the numbers around any way you like to see different scenarios. Falcon's suggestion is correct on the sizing. Your 140k is a monster. With a smaller heater there may be days you just don't want to be out there. In my time I did plenty of cold weather tig on power houses and as you know, itis difficult to do your best work when you have the cold weather shakes.

 

[stingry]

I have a 2 car garage. If I remember correctly it's 24 wide, 20 tall and 8 feet at the ceiling.

There is NO insulation in the garage at all.

I have a 140K BTU Reznor heater that I can set up.

Thanks gents!

I assume that this is going to have to be mounted with proper ventilation. This will not be cheap and the landlord may have objections, especially if you take it with you and leave a big 'ole hole in the roof!! If you are just going to be there a year, I would forget the Reznor and buy a bullit type space heater. The new ones don't smell as bad as the old ones and would seem to be well-suited for your application, since you will not be out there that much and have no insulation.

Cheers
Steve

 

[NUTTSGT]

Have you inquired with the owner if he'd let you insulate and discount the material cost off the rent ? Doesn't hurt to ask.

 

[mpls|cafe|racer]

Will let me insulate, won't discount. I'm venting by removing one of the Windows and making a vent panel. (single pane and useless thermally anyways.

Thinking I'll probably do some insulating anyhow since I mentioned it again and he dropped off 9 spare rolls he had to get me started. Haha

I'm not interested in buying another heater. I already have this one.

So I suppose j should ask this, what are the DRAWBACKS to using this size heater?

I'm assuming that cycle wise its either a smaller heater that runs more often and longer to try to maintain temp, or a bigger heater that runs less often and shorter.

 

[Jackfre]

Okay, it is like not being able to control the amperage on your welding machine and it is set on high and you are welding sch 10 or lighter! now there's a picture for you. Or, it is like doing your finish work with a 16# pin hammer.

It will not operate as efficiently as a unit that is properly sized. You will not be as comfortable. You say you do not get this hvac stuff. The sizing advice is correct. Don't just discount the swapping out idea. You will benefit from it.

 

[Falcon67]

I'm not an expert, but I seem to recall there may be issues with small tanks and regulators feeding a big draw appliance. I know my small 30K propane heater will start to freeze the bottom of the tank after about an hour, your big 'um might freeze it up a lot quicker. If the tank gets cold, it can't feed the appliance.

Some reading material:
http://countryplans.com/smf/index.php?topic=10186.0

 

[D.J.]

My suggestion is to install the insulation and call LL and tell him you have it up maybe he will bring you some more if he has nothing in the labor he may bite.

 

[bd8134]

As you have the 140k Reznor you should use it. It is certainly better than no heat at all. It will heat up your space quickly but you will lose a lot of heat also with no insulation. The heater will keep cycling on and off more often than a correctly sized / insulated area, if you have a thermostat. Its these short duty times that might shorten the life of the chambers, ignitor, etc.
Make sure you vent it correctly and pay attention to the correct slope if venting horizontal. The size of tank / tanks might be a problem, is your LL okay with you putting the tank outside? Search on the web for freezing tanks and you will begin to understand the problem this might cause with a tank too small in cold weather. You dont want to place the propane tank inside your building, propane gas is heavier than air. Doubling up on smaller tanks can help.
My suggestion is to not use bullit or torpedo heaters, they do smell and create quite a bit of moisture.
Your LL most likely is looking at his bottom dollar, how do I make more money from renting this space. If this garage is in a commercial area it might be cost effective to have the garage insulated so he can get more money when you move on. If the garage is in a residential area, that is different and the LL might not be able to charge a premium for this luxury. At the moment it is for your convenience, try to get the LL to meet you half way on costs and then agree to a rent increase after a year??