Using 20# propane bottle on fixed heater

[surferstick]

I've seen the question asked and discussed within other threads, but haven't found a definitive thread on the subject. My apologies if my searching has failed ;-)

In my part of the world, you have to rent a large propane tank at $80 per year, plus propane used. I currently heat my garage on Saturday morning only, with a 50K btu torpedo heater, and I have yet to spend $80 in propane in an entire winter. I found a great deal on a new Mr. Heater 45K vented heater, so I bought it, still planning on only heating the garage on Saturday mornings. Now I have to consider how to feed the new heater.

My first thought is that if a 20# bottle can feed my 50K torpedo, then I should have no problem feeding my 45K ceiling mount. If code requires it (as implied in another post), I can install a fixed line from the heater down to the corner of the garage when I can attach my 20# bottle. I though I would just use the hose/regulator from the old torpedo to attach to the new fixed line.

I know I will have to fill the bottle more often now, but other than that, does anyone see problems with this setup?

Thanks

 

[Jackfre]

I'm surprised the system worked as you describe, running such a large heater on such a small tank. The issue with propane is based upon the "wetted" surface of the tank. The liquid has to vaporize in the tank and pass thru the regulator. If the draw on the tank is to large the regulator will freeze up and you are out of luck heat wise. This condition is temperature dependent as well. The colder the tank, the less it can output and the faster it will freeze. The temptation is to leave the tank in the space. Many do, but it is not a good idea. You will be better off with a larger outside tank.

 

[trbomax]

Even if it would feed w/o freezing up, the tank should be outside. If you are set on doing it this way,scrounge up a set of 40# cylinders from a travel trailer. They will have a twin regulater setup that auto switches when one tank is empty,plus they will work with a 50k draw.

 

[DeuceDude]

All propane regulators are not created equal !!!
DO NOT just hook up your torpedo Reg to the new heater without checking.
My torpedo heater has a 10lb reg pressure, way too high for most other heaters. I have a vent-less wall heater and the pressure for that is half a pound, you will often see them rated as 11" WC. If you just use that hose and reg you could be supplying your heater with 20 times the needed pressure, damaging it or worse!
I have a vent-less radiant wall heater with half pound reg, 15 foot hose and 60lb bottle inside the shop in the corner, no sweat. Is it safe??? I don't lose any sleep over it. Its your call.
BTW, regs and hose are cheap!

 

[surferstick]

Good points everyone. I will buy a new low pressure regulator and hose.
Any other thoughts?

 

[Camper]

Been running a set up like you are talking about for years....run the heater on 40 lb RV tanks....use a regulator for an RV also. Have the tanks sitting in the corner of the garage and never worried much about it. What makes that so much more unsafe than having the tank attached to a short hose leading to a portable construction heater ???

 

[trbomax]

Been running a set up like you are talking about for years....run the heater on 40 lb RV tanks....use a regulator for an RV also. Have the tanks sitting in the corner of the garage and never worried much about it. What makes that so much more unsafe than having the tank attached to a short hose leading to a portable construction heater ???

I guess its not more unsafe,I just do not like propane tanks that are being switched all the time in the shop. If they were checked for leaks with a spray leak detecter when they were changed out ,they would be OK. Probably no one but me leak checks his acetelene tanks when they are changed either,I'm just paranoid about gas leaks I guess.

 

[slip knot]

I use a 20 lb bottle on my 60K btu Dearborn heater in the shop it'll run 8-10 hrs on low heat. Turn it up and it'll last less. I got @10ft of 3/8 hose on mine. I leave the bottle out in the drive and run the hose under the overhead door seal. Works ok.

I've got a 150 gallon tank but haven't got it plumbed up to the shop yet.

 

[theoldwizard1]

Best advice I saw here was put the tanks outside or build a separate room with outside ventilation at the floor. LPG is heavier than air and it will pool at the lowest spot.

Personally, I would shut off the gas at the tank(s) when not in use.

 

[IONH]

I am looking to do the same thing (install an overhead propane heater, 75k BTU Mr Heater).

Anyway, 40 pound tanks are cheap at about $90 from Lowes (minus 10% for a movers coupon). Total weight is about 80 pounds full, not too bad.

You can buy flexible LP hose online for cheap as well, to easily run it whatever distance in order to place the tank outside.

My building inspector won't allow any source of heating with a fire which does not have a dedicated intake port from a fresh air source. I do not agree with his analysis of the code so I will not be getting a permit. I will also be removing the tank and line when warm weather comes so it is really only 4 or 5 months where it will be installed and visible from the back of my detached garage.

OP, have you figured out what pressure these Mr Heater propane heaters need?

 

[dave67fd]

For NG the 45k/75k's gas line pressure should be at 5" wc min.. LP is 10.4" wc min. Both are for 2000' altitude and less.

All this info is provided in the operating manual which all applicable parties should all print out and read thoroughly.

http://www.garagejournal.com/forum/showthread.php?t=138609

 

[jvitez]

I bought a 40 lb propane tank for my 35K btu radiant heater, and bought a T-block/hose set up to gang two 20 lb tanks for my 30K torpedo heater. Lasts a long time for my intermittent use.

For your low use, why not just get two 40 lb tanks, gang them together, and you'll probably have your winter's worth of propane for your once weekly use? No worries about frequent tanks changes and gas leaks either.

 

[surferstick]

Sounds perfect, so that is exactly what I will do.
Any comments on using flexible LP hose/regulator for my first 5 feet, then join onto copper line all the way to the heater? I will fasten the copper to the interior wall at the ceiling level. Is there a code requirement for how far apart each fastener should be? Also, should I be flaring the line, or using compression fittings?

Thanks

 

[trbomax]

Compression or flare is ok unless you are takeing it apart a lot,then I'd do single flare.

 

[NWOhioChevyGuy]

Was in Lowes today and they have tanks about 4 foot tall (don't know the size) for $129

They have to be 3-4 times the sizeof a 20# tank

 

[casetractorfarmer]

Was in Lowes today and they have tanks about 4 foot tall (don't know the size) for $129

They have to be 3-4 times the sizeof a 20# tank

Those would be the 100 pound tanks about 23 gallons of propane it would be perfect for this application

 

[IONH]

Those would be the 100 pound tanks about 23 gallons of propane it would be perfect for this application

About 170 pounds (weight) full.

Just ordered the 75,000 BTU Mr Heater from Amazon today for $10 more than Northern Tool and free 2nd day shipping. I'll start another thread for the install when it happens.

 

[6768rogues]

In our area, there is sales tax on portable tanks such as barbecue tanks but not on heating fuel. I had a 100# tank and if I took it to get it filled, I paid a high price and sales tax. When I got a larger tank, a truck delivered the propane at a lower price with no sales tax. Go figure.

 

[Camper]

Probably works about the same in my area....
I just really do not have room outside for a big tank and don't see a reason to pay a rental fee on a tank for the small amount I use.

 

[reygydfhwe]

I bought a 40 lb propane tank for my 35K btu radiant heater, and bought a T-block/hose set up to gang two 20 lb tanks for my 30K torpedo heater. Lasts a long time for my intermittent use.Was in Lowes today and they have tanks about 4 foot tall (don't know the size) for $129

They have to be 3-4 times the sizeof a 20# tank

 

[casetractorfarmer]

I bought a 40 lb propane tank for my 35K btu radiant heater, and bought a T-block/hose set up to gang two 20 lb tanks for my 30K torpedo heater. Lasts a long time for my intermittent use.Was in Lowes today and they have tanks about 4 foot tall (don't know the size) for $129

They have to be 3-4 times the sizeof a 20# tank

Ya those are 100 lb tanks they are 50 dollars to fill here in sturtevant wi 20 lb tanks are 11 dollars

 

[Highbeam]

Ya those are 100 lb tanks they are 50 dollars to fill here in sturtevant wi 20 lb tanks are 11 dollars

Could be due to them holding 5 times as much propane. The difficulty will be in handling, transporting, lifting, those very heavy tanks when they are full.

 

[surferstick]

Just an update from the OP.
I called a local installer, who said it was no problem to use a 20 pound bottle. For insurance peace of mind, I had the pro install the unit, and it works great. Of course it is pretty much summer now, but on a couple of rainy mornings, I used it to bring up the temps to comfortable levels, and it worked awesome.

I may yet go buy a 40 pound bottle just to save refill aggravation.

One thing I wasn't expecting on the install, was that the typical propane regulator is not sufficient. I had to purchase (about $50.00) a larger HP/LP regulator. I'll post pics later this weekend.

 

[Falcon67]

Could be due to them holding 5 times as much propane. The difficulty will be in handling, transporting, lifting, those very heavy tanks when they are full.

I was offered a free 100lb tank - and passed for that reason. No good way to move or fill the tank.

 

[DOUGD]

Did fire place gas logs with a 20# tank, system worked ok but the line often needed to be bled after each tank change. Bought a 60# tank it is heavy when full but manageable, and lasts me all winter . It was well worth it for the extra burn time and less tank swapping.

 

[Mmfh]

I use a 60 lb tank with my 75k, its heavy when filled but one person can grunt and grown and get it back home and into the garage without too much trouble.

Those 20lb bottles just don't last very long with that size heater.