Propane Gas Line Size?

[GearHd6]

I did a little searching on here and couldnt really find the answer I was looking for. I've got a Dornback 45,000 BTU power vented heater (Mr Heater, Hot Dawg clone). I'm wondering what size gas line i'd need for this application. I live on Connecticut so it gets pretty cold over the winter. It looks like i'll need 13 feet of line from the heater to the tank which will be outside. Does anyone have any ideas? Can you over kill this or will that hurt performance? Thanks

 

[Franz©]

You should have /12" copper from the regulator on the tank to the building. From there, all lines should be 3/4" black iron pipe. When you get within a couple feet of the heater you can switch to 1/2 black iron if it's more convenient.

Propane runs at 11 inches of water colum pressure after the regulator, so line resistance is fairly high. Using 3/4 black iron provides you with a bit of a buffer since the line acts as a low pressure tank.

 

[Junkman]

I'm also in Northeast CT and know what you mean about cold. My 75,000 BTU Mr. Heater ceiling mounted heater is piped with 5/8" copper from the tank to the outside wall of the garage. Then it goes to 3/4" black iron pipe that goes through the wall to the outside. On the inside, the 3/4" black iron pipe goes up the wall and to the heater. I hard piped mine up to the heater and included a drip leg. Then I changed over to 1/2" copper with flared ends. When the outside temperature drops, the propane pressure will also drop. You don't want to have your heater starving for fuel, so don't skimp on the piping.

 

[GearHd6]

Thanks for the info. So you guys have a hard steel line hanging outside your building going to the tank? Can I just run copper from the heater right to the tank? It seems like I see that done quite a bit but I guess that doesnt mean its correct. Thanks.

 

[Junkman]

Thanks for the info. So you guys have a hard steel line hanging outside your building going to the tank? Can I just run copper from the heater right to the tank? It seems like I see that done quite a bit but I guess that doesnt mean its correct. Thanks.

NO!!!!!! I said that I have steel pipe going through the wall to the outside, and then it changes over to copper........... If it were not 5:45 AM, I would go out and take a picture for you, but I don't move very fast this early in the morning..... You can do anythng your little heart desires, so long as you can get it past the fire or building inspectors. By law, you need to pull a permit to install a heater. If you don't, and the heater sets the home on fire, your homeowners insurance will have an out for not paying.

 

[Kevin54]

For propane all you need is 3/8" soft copper. That is code around here and that is what the guys put in that installs the tanks from the propane company. Buried underground with nothing else but dirt on top. The black iron etc, is for gas line.

Kevin

 

[Franz©]

Kevin, you better recheck the CODE.

Copper was used inside buildings, very well I might add, for propane for years, but that changed about 13 years ago. The American Propane Gas Association now insists on black iron inside of buildings.

The current trend is to put a primary regulator at the tank, dropping pressure to around 10psi, and a secondary regulator where the propane enters the building to make up for line resistance in the ½" copper coming from the tank. A 45kbtu apliance will require proper line sizing or the burner will starve.

 

[Junkman]

For propane all you need is 3/8" soft copper. That is code around here and that is what the guys put in that installs the tanks from the propane company. Buried underground with nothing else but dirt on top. The black iron etc, is for gas line.

Kevin

The code in Ohio must be a lot more liberal than the code in CT, where the original poster is from. Direct burial of copper for gas lines hasn't been allowed in many years. Today, you have to trench, fill with sand, and install a special plastic pipe, with expensive ends where it goes into the ground and where it comes out of the ground. I was told that being a garage, it had to be black iron piping to the heater, and a short pigtail was allowed from the wall to the heater itself. I don't know if soft copper tubing is still allowed for new construction in hoes today, but it was when I built my home back in the early 1980's.