This propane heater installed here in my barn/shop?

[Steve Mathews]

In advance of a more permanent setup to heat and cool my shop I picked up this used propane heater on CL to carry me through the winter. The corner location shown is not ideal but is the best I can come up with. Because of the dust collection duct overhead the bottom of the heater will only be about 6 1/2' high. Anyone see that as a problem? Can I supply this 125k BTU heater with a 25 gallon tank? Eventually I'll be installing a couple of mini splits. Maybe the propane heater would still be a good idea to keep for those really cold days.
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[Lee Schierer]

Where does the exhaust go?

[Steve Mathews]

Where does the exhaust go?

The exhaust is on the back of the unit and would go through one of the walls in the corner. It would be a horizontal run not vertical. The installation instructions from Reznor states that it has to be at least 18" from a wall.

[Doug Walls]

Can I supply this 125k BTU heater with a 25 gallon tank?
If you're referring to what's normally called a 100lb. tank that will hold about 24 gallons of LP. It may work for a while, but as the propane is used up the tank will start to freeze up & the withdraw rate will be cut way down. If you were thinking of a 20lb. tank like used on a BBQ. Then it wouldn't last long at all, if it even works in the first place.

According to this chart a 125,000 btu heater would require two 100lb. tanks connected together to work ok.
http://www.nbmc.com/heaters/lpchart.html

[Doug Walls]

Just for a comparison, I have a 34,000 btu RV furnace DIY rigged up like a window AC unit that's in a normal two car garage.
The walls are insulated but there's no ceiling yet & the roof is not insulated.
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I'll go through a 30lb. tank in a weekend if it's around 30 degrees °F outside.

[Bill Dufour]

If this is just in San Diego to take a little chill off you tank will be fine. Colder then that, ask the folks who live in colder climates.
Bill D.
SD was below 60 high this week! My cousin in Escondido is colder in winter and warmer in summer.

[Jack Frederick]

125 k is a substantial device. How big is your shop? If the unit sees extended run times you will likely freeze the regulator. Regulators are pretty robust, but regular freezing is not something that keeps them happy. Also, are you going to have lp delivered or are you going to be carrying the tank for fills? If you are handling this it is going to get really tedious. I did this for a while and my days of being able to lift a full 100#er are long gone. It is a good way to get hurt. I think this will accelerate your mini-split purchase;)

[Doug Walls]

If you are handling this it is going to get really tedious. I did this for a while and my days of being able to lift a full 100#er are long gone.
Been there done that also!
I got rid of my 100lb. tanks after I sold my pickup truck, by law here in Michigan & most other states a 100lb. tank needs to be transported upright.

[Steve Mathews]

125 k is a substantial device. How big is your shop? If the unit sees extended run times you will likely freeze the regulator. Regulators are pretty robust, but regular freezing is not something that keeps them happy. Also, are you going to have lp delivered or are you going to be carrying the tank for fills? If you are handling this it is going to get really tedious. I did this for a while and my days of being able to lift a full 100#er are long gone. It is a good way to get hurt. I think this will accelerate your mini-split purchase;)

The shop is around 2000 sq. ft. with about a 30 ft. high exposed ceiling at the peak. I would be happy to get the shop temp in the 50s or low 60s while it's below freezing outside. I'm in the high desert of Arizona so that doesn't happen often, maybe 20-30 days out of the year. The house is heated with propane and I get that delivered. Unfortunately the shop is too far from the house tank to make it practical to use. The heater just fell in my lap and thought it might be a good stop gap before installing the mini splits. I'm also a little concerned that the mini splits will not bring the temps up fast enough to my liking and that the propane heater might be a good boost.

As for my 100 lb. propane tank I didn't realize you can't transport it without it being upright. I've only filled this once so far and the supplier said lying it flat was OK. I'll have to check more into that. I'll also check to see if my home delivery will also fill the 100 lb. tank. I'll also check on getting another tank or something larger. The only reason I got the 100 lb. tank originally was to supply a blacksmithing forge.

[Jack Frederick]

Assuming good insulation, windows and doors a 125 should flash fry the place pretty quickly. Have a chat with your propane company letting them know your situation. They are in the business to sell gas and hopefully keep customers so it is their best interest to work with you. You know the physics. The hot air will stack up at the top regardless of gas or minis’. A couple Big Ass fans or such may work for you. Most of the minis available today are wireless capable so you can probably start it remotely but you are correct that it will take some time to bring the temp up.

[Doug Walls]

As for my 100 lb. propane tank I didn't realize you can't transport it without it being upright. I've only filled this once so far and the supplier said lying it flat was OK.
As long as your propane supplier is ok with it lying flat, you're probably ok! I have moved several of them lying flat & never had any problems, but it's technically illegal here in MI. I eventually made a rack for the back of my old truck so I could transport them upright.


I'll also check to see if my home delivery will also fill the 100 lb. tank.
They may be able to fill a 100lb tank from the delivery truck, but the suppliers around me have something like a 100-gallon minimum delivery amount. In your case being that you also heat your house with propane, they may combine the two?

[vince dale]

Doesn't propane heat produce a lot of moisture?

[Ron Selzer]

Doesn't propane heat produce a lot of moisture?

yes, however it all is exhausted outside with this setup

[Doug Walls]

Doesn't propane heat produce a lot of moisture?

Before rigging up this RV furnace, I used to use two of those tank mounted heaters like these.
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They worked ok, but even with the garage door opened a little to allow ventilation I would start feeling lightheaded after being out there for a few hours. The amount of moisture they put out caused a lot of my cast-iron machine tops to rust if I didn't wipe them down with WD-40 after running the heaters.

Like Ron Selzer mentioned
yes, however it all is exhausted outside with this setup seeing that the RV furnace vents the exhaust outside there's no added moisture. The other thing that's nice with the RV furnace is that it uses outside air for combustion, so there's less of a concern with paint or stain fumes.

[Bill Dufour]

Propane makes about one pounds of water for every pound of propane burned. Not a problem for a sealed system with a chimney.
Bill D

Edit: One pound of propane burned makes 1.63 pounds of water, and other stuff like co2 as well.