Heating a shed

[mbrule]

I don't know if this is the best place to post this (mods, feel free to move if not). I would like to call upon the collective wisdom of the group. I have a 12'x 24' shed on my property that I want to heat. I presently use an antique two burner kerosene stove when I am out there and will likely continue to do so. However, now I want to keep it heated all the time (at least above freezing).

I have installed a ceiling (loft) so the ceiling is about 6.5 feet except over the single garage door where it is slightly higher to clear the tracks. I am going to insulate the ceiling, the walls, and the garage door. Leaving the floor, which is plywood with air gap under, I think I am going to put a layer of 3/4 OSB over the entire floor to stiffen it, and provide some (albeit not much) additional insulation.

Now my questions:

Any suggestions on how to insulate the floor? I will be storing a car in the building.

What is a good source of heat? Below are my thoughts:

I am considering electric base board or an electric heater, cheap and easy to install, but might be pricey to run. How many watts would I need?

Natural gas heater. This would likely be the best but would be pricey to install as the gas line would need to be run (and permitted) from my house.

Propane heater. middle of the road between gas and electric as far as install and cost to use, would have to deal with a tank in the front yard of my house.

Oil fired heater, not really an option as I do not want to store any more oil outside. I already have a tank for my garage and it is an expensive double containment tank as I am on a pond. No, it is not close enough to use for the shed too.

Any and all advice appreciated, I will try to get some pictures, I know everybody like them!

 

[sweettractors]

Insulated good, 3000 watts should keep all above freezing. Ken Sweet

 

[dave1949]

For a propane heater, you could use a couple 100 gal. portable tanks that you refill as needed.

Electric I bet would be expensive to run. You have four outside walls and will probably end up with much less than the standard residential level of insulation for walls, ceiling and floor.

For any heater, you may have to search out a low-temp thermostat. 50* is a common lowest setting. You don't need to pay to have it that warm.

You could do your insulating then buy a couple of inexpensive electric 'milk house' style heaters, they cost about $30 for a 1300 watt unit with fan and thermostat that can set very low. See how that goes and make choices from there without having much invested.
Dave.

 

[crusty 1]

I agree with Dave1949.Consider a small wall hung propane heater.You can buy vented or unvented models.We use unvented heaters here in no.mn. to heat fish shanties with no problems.The heaters can be bought fairly cheap and don,t cost that much to run.I,d say a 15-20 th.btu unit on a thermistat would work out well.I,d mount it as low to the floor as you can:thumbsupave

 

[dave1949]

Should have mentioned TSC sells 100 gal. propane tanks. Also wondering if using propane is asking for excess condensation in a cool room without much ventilation? Burning propane produces lots of water vapor and at low heat, you will have surfaces cool enough for condensation to form I am guessing. Something to think about.
Dave.

 

[timswi]

Should have mentioned TSC sells 100 gal. propane tanks. Also wondering if using propane is asking for excess condensation in a cool room without much ventilation? Burning propane produces lots of water vapor and at low heat, you will have surfaces cool enough for condensation to form I am guessing. Something to think about.
Dave.

My thoughts as well..Unvented gas heaters generate a ton of humidity even in moderate temperatures.

 

[Kays Supply]

Another option is a used/takeout furnace. I am a plumbing contractor, I see the HVAC guys take out pretty good LP furnaces and install new ones when the AC goes out. They usually junk them, so if you let some HVAC guys know you are looking, one might come available. You can stop the humidity issue that way.

 

[kenmac]

Run the nat. gas line from your house yourself. It isn't that difficult. Don't know the cost of nat. gas in your area,but around here,it's usually cheaper than propane . check the adds for used furnaces..NOTE,,,, Make sure the combustion chamber is ok b-4 you purchase / install a used furnace

 

[crusty 1]

you guy,s are right about the cond.,fish shanty at -30 is a different situation than an insulated bldg.Dave

 

[Kubota-guy1911]

It it's insulated good electric baseboard won't be that costly. I chose electric so I could paint and use flammable solvents without worrying about an open flame. I got some used 6" thick batts to insulate the attic with, had enough for 2 layers. My side walls are R-13 fiberglass covered with 7/16" osb on the inside. I sheathed the outside with thermax which also helps. I heat a 12 X 16 shed to 50 degrees for less than $20 during the coldest months (below zero). I used (2) 2000 watt baseboards with a 2 stage thermostat and the only time I've seen the second stage come on is when I went in and turned it up to 70 to do some painting. Works good. Another advantage of the baseboards is no air blowing dirt around on my just painted project. Also no fan motors to fail later.

kj

 

[magicheater]

What are you planning on doing in there?

 

[mbrule]

Thanks for all the input!

I just want to keep the shed moderately heated all the time for the storage of a classic car. It is where I will do occasional woodworking projects (car will go outside). I will also wax the car during the winter and occasionally just hang around out there and drink beer! That said, it does need to be something that is safe, as it will be unattended most of the time.

I have the antique kerosene stove in there that I can use when I am out there, it is already installed and I enjoy using it occasionally as it is the stove that my Dad heated our apartment with when I was little. Though if I install something that proves economical, I can remove or not use the stove.

The ceiling will have 6 inch fiberglass insulation, 3.5 inch in the walls, The ceiling will be sheet rocked, I am not sure if the walls will be luan, sheet rock, OSB, or pegboard, or some combination. The door will have 1 inch foam insulation.

Also, space is at a premium, I do not have room for a full size furnace.

I am chicken to mess with the natural gas lines. If something ever happened, and it was proven that I messed with the lines with no license or permit then the insurance would not pay. And quite frankly that unlimited supply of gas scares me!

Think that answers everyone's question, keep the suggestions coming! Thanks!

 

[radman1]

I have a heated 24x24' shop in my pole barn shed which is 45x72'. I use the shop to work on cars, wood projects, repairing stuff ect. I use a 80,000 btu hanging Modine heater that runs on propane. My house uses a 500 gal propane tank and I ran a second line to the pole barn shed from the propane tank. However, a separate 100-250 gal tank would also work. The walls are 6" bat insulation, the ceiling is 10" blown insulation, and the floor is cement with 2" styrofoam under the cement. 2 walk in doors and insulated 10x8' roll up door. I use a thermostat designed for farm use (pig nurseries) than can be set to below freezing. I set the thermostat at 36F in the winter to keep stuff from freezing. The heater is much larger than needed, but on bitterly cold days I can heat the shop in 10 minutes and be in a tee shirt. A 30,000 btu furnace would still be plenty for my shop. Electric heat would take way too long to heat up my shop.

Most efficient propane or natural gas furnaces are electric ignited with power vent. Mine has typical flame pilot and traditional venting. I figure the small amount of heat from the pilot light helps to keep the shop from freezing in the winter. I shut off the pilot in the spring, summer and fall. In the floor heating is way overkill for limited useage. I would choose natural gas if it was available because it is cheaper and don't have to mess with having a propane tank filled.

I cool my shop in the summer with a 8,000 btu wall A/C and it does ok but probably on the edge. A 10-12,000 btu A/C would probably be more ideal. the pole barn shed covers much of the shop and most of it is not in direct sunlight, That helps with cooling.

 

[kidr]

What ever you use keep it at least 18 inches off the floor to avoid igniting gasoline fumes.

 

[LBrown59]

I agree with Dave1949.
1*Consider a small wall hung propane heater.You can buy vented or unvented models.We use unvented heaters here in no.mn. to heat fish shanties with no problems.The heaters can be bought fairly cheap and don,t cost that much to run.I,d say a 15-20 th.btu unit on a thermistat would work out well.
2*I,d mount it as low to the floor as you can:thumbsupave

1* This is a 30000 BTU un vented NG wall heater mounted on the back wall about 6 or 8 inches above the floor .

This is a common 20 inch Box fan mounted on the same wall near the ceiling.
It is controlled by a thermostat I installed in the fans cord.

The fan is angled slightly downward so as to push the warmed upper air forward and towards the front of the building.
The room size is 12 x 22 with a 10 foot ceiling .
~~~~~~~~
2* The OP stated he would be storing a car so this would require the heater be at least 16 18 inches above the floor.

I was able go as low as i wanted because no auto or gasoline is stored or contained in the building.

 

[mbrule]

What ever you use keep it at least 18 inches off the floor to avoid igniting gasoline fumes.

Does this mean that I could not use electric baseboard?

Right now that is what I am favoring, because install cast is very low and if it ends up being too expensive, I could consider another source, and keep the electric for use when I am out there and want to warm it quickly.

 

[sweettractors]

Run the nat. gas line from your house yourself. It isn't that difficult. Don't know the cost of nat. gas in your area,but around here,it's usually cheaper than propane . check the adds for used furnaces..NOTE,,,, Make sure the combustion chamber is ok b-4 you purchase / install a used furnace

Would you run a line from the house to the shed from the high pressure side or the regulated pressure side of the meter? Ken Sweet

 

[mbrule]

Would you run a line from the house to the shed from the high pressure side or the regulated pressure side of the meter? Ken Sweet

I am certainly no expert and would only have gas lines run by a permitted and licensed plumber. Based on the lines in my house (furnace, stove, water heater) everything "tees" from the regulated side.

 

[sweettractors]

With a classic car on storage, I would stay with the cleanest burning device that I could find. I think that would be electric. All others will sooner or later leave a residue in the heated area. Ken Sweet

 

[kenmac]

Would you run a line from the house to the shed from the high pressure side or the regulated pressure side of the meter? Ken Sweet

You would have to run the line after the meter. So, the gas would be metered. Most regulators here, are b-4 the meter. Unless you have what we call a 2# gas system in your home. If this is the case you can run 2# of gas pressure to the shed & reduce the pressure at the appliance