I have a chance to get a 100,000btu Reznor celing mounted heater for a good price right now, but it's Natural Gas powered, and I have no way to get gas to my shop, so I need propane.
How different are the heaters? Is it just a matter of adding a propane regulator and perhaps a gas valve?
The heaters aren't that different, you need a
conversion kit. The kit normaly comes with the
applience when purchased new.
The kit comes with a set of Jets, the jet sizes
ARE NOT the same with Natural Gas as with LPG
Propane, a regulator also. Plus a few other items
that you need for the conversion. Only a licensed
technician should perform the conversion for you.
Check also with local and state laws governing
the installation of Natural / Propane Gas
appliences. Most areas prohibit the sale of the
conversion kits to unlicenced personnel.
In addition to Jamie's excellant answer, before you buy the heater, get the model number and make sure that it's new enough that you can actually GET a conversion kit.
If the heater is more than, say, 10 years old, you may not be able to.
I can't recall whether the NG or the propane jet is larger. If you can't get jets (I'd be stunned to learn of that. Reznor has been selling heaters since the Chixalube strike.) You could drill drill them out.
Before you do that start the heater on propane and monkey with the combustion air at the jet end of the burner. Quite often you can get a good fuel/air mix with the available adjustment. The only glitch is that Propane will burn a bit hotter meaning you'll have to be sure that plenty of room air flows past the exchanger.
You still need a propane regulator. And 100,000 BTU will ice up a 20 lb cylinder in 1/2 hour of burning. Better talk to the propane guy to see what cylinder to get that he can legally re-fill.
I have propane in my house for heat, hot water and cooking. I have what they call a "pig" in the back yard which they fill from time to time, they also use smaller cylinders which stand 3-4 ft. high.
What I would do is get on Reznors web site to locate a conversion kit then look in you local phone book for propane co. there should be a few in the area then just call & ask how much to install the cyl. and to convert the unit it shouldn't cost to much. If they don't do the install then then you would have to find a plumber with a gas license, most won't connect unless you pulled a permit for the work.
If the unit is new the orifices might be already in the unit, I just bought a new stove and all the orifices were on a pc. of metal bolted to the gas inlet assembly the were all maked for NA( natural gas) of LP (propane).
Shouldn't be to expensive to install and the price of propane isn't to bad a little higher then oil but it gives you more BTU's.
If it has electronic ignition it should be fairly new.
Propane jets need to be smaller than nat. gas. I have converted hot water heaters from nat. gas to propane by sodering shut the jet and drilling out a smaller hole. You need to experment to get the orfice and air adjusted to burn a blue flame.
Trutemper, the problem with drilling out jets, especially on propane, where you don't have a meter that you can clock, is getting the correct firing rate. (overfired)
All gas burners can be fudged, sorta, but maybe at some expense of reliability, safety, and ignition reliability.
What I mean by that is, you can drill the jets (too big) and fudge "some" by dropping the manifold pressure, or vice versa, but---
there reaches a point where the damn thing just doesn't work right, such as noisy, blowing flames, etc.
Pilot systems, especially, can be fussy, because incorrect ignition (due to poor adjustment) of the main burner can blow out the pilot.
Also, because your drill bit "roughs" up the inside of the jets in an uneven manner, there is no guarantee that a carefully drilled/reamed jet will flow the same as it's brothers, thus overheating and warping or cracking various sections of the heat exchanger cells.
In addition, as I mentioned, without a meter, how do you know when the unit is overfired? With a normal propane burner, you assume this by setting the required manifold pressure, and insuring the correct (factory) jets are in place. On a ducted system, you can double check by measuring the temperature rise, something that is not really possible on a unit heater.
(I guess you can assume that if it doesn't cycle on the high limit, it's "ok")
It's been a number of years already since I've serviced atmospheric gas burners, and even now, I'd be reluctant to judge a burner as over/ under or correctly fired just by visually inspecting the flame size.
This is fairly thin ice, and is pretty much forbidden by most any codes, or just plain servicemen's common sense.
I have converted quite a few things from NG to LP, I just did a fryer last week. you have to change the main jets (smaller orfices) and the pilot orfice(s),
also the regulator on the main valve needs to be changed (sometimes just a spring) as the pressure of propane is higher than NG.
If this is a newer unit with electronic ignition or forced air combustion, this is a whole different story, and a bigger price tag. Also much more involved.
The starting point would be Resnor, if they have the conversion, then that would make the job easier. If not then your next step would to find a gas tech in your area, he should know how to do it and how to set it.
No offense, but if you are asking, it could be tougher than you think. And will you be comfortable with the furnace after you do convert it.
One thing about propane that scares me, it is heavier than air. This means it will pool until it finds a combustion source. Natural gas is lighter than air and it takes a lot for it to accumulate, it likes to disperse.
best of luck, and be careful.
Great replies everybody, thanks!
I mentioned to a friend that I was on the market for a heater, and he gave me an oil furnace from a mobile (trailer) home. He's had it in his garage for years but no longer needs it (house is for sale). I can say; if you can find one of these units, they are the PERFECT shop heaters.
It's just like a regular oil (or gas) furnace, but requires no ductwork other than a flue, a 120v outlet, and a thermostat. If you're not in the shop often, you can run it from a 5gal bucket.
So much better than salamanders or other heaters that burn up oxygen in the room you're trying to live in...