Underground natural gas line for garage furnace install?

Daox · 10-09-17, 05:23 PM

This past weekend I acquired a natural gas furnace from my step father. He had the one in his house replaced since this one was acting up on him. His son used to be a HVAC tech, and said it needed a new regulator valve. Its an older furnace, so he opted to replace it instead of fix it. I figure no problem, I can put one of those in, so he gifted it to me.

Now, I'd like to put this furnace out in my garage. I believe the unit is ~40-60k BTU. This means I will need to run a natural gas line probably about 10 feet from the meter to my garage. Is there anything special that I need to know about burying natural gas line? What gas line is rated for underground use? Googling shows a lot of arguing about why this can't be a DIY job.

jeff5may · 10-09-17, 06:40 PM

Same basic deal as running a line set for an air conditioner.

pinballlooking · 10-09-17, 09:51 PM

I did it to my greenhouse.
http://ecorenovator.org/forum/lawn-g...-build-77.html
You will need a couple Risers.

Chamfering tool

https://www.youtube.com/watch?v=42L5c2zSDCE

https://www.youtube.com/watch?v=zC0-82xqfNs

You need to put a tracer wire in the trench but make sure the wire is not touching the pipe in case of a lighting strike.
Then you need to pressure test it.

It was very expensive to have a small amount pipe shipped to me so I had to buy 250’ roll. Once you know how much you need drop me a pm I am sure we can work out a good deal for a small amount pipe.

Daox · 10-11-17, 01:36 PM

Thanks Pinballlooking. Thats very kind of you to offer.

jeff5may · 10-11-17, 01:53 PM

Who said shark bite fittings are not good enough for everything? Cuz that's what the stab fittings look like to me.... I'm sure they're gas industry shark bite fittings.

pinballlooking · 10-11-17, 02:23 PM

They are very similar to shark bite fittings and they pass code.
I did not know anyone with fusion equipment. So compression fitting it was.
It held the pressure test fine.

oil pan 4 · 10-11-17, 11:35 PM

What ever you use it has to be to your local code.
For example in new Mexico you can not use copper or aluminum line.

bennelson · 11-20-17, 05:09 PM

My Dad put a natural gas furnace out in his shop, which is attached off the back of the garage. The dog's kennel is also off the back of that building, and there's a small dog door for the animal to get inside to an interior box.

The detached garage does NOT have natural gas running to it. There was also a pond, rock garden, and driveway in between the house and the garage, so trenching and burying natural gas pipe to there didn't make sense.

He instead converted the furnace to propane. My understanding is that it's pretty easy to do that, it's mostly just an orifice change. Lots of people live outside of towns, where there's no natural gas, and instead have one of those large "pill" propane tanks in their yard. So, there's a lot of gas-to-propane adapter kits out there.

The furnace itself is in a "lean-to" area which was originally outdoors, but under the overhang of the garage roof. That area was walled in, but it's still essentially outdoors. The main vent out from the furnace is wrapped in insulation before going into the shop.

The other thing to think about here is that the NEW furnaces are CONDENSING. They magically pull out the "latent" heat which means more of the natural gas fuel gets converted to heat (higher efficiency) but that you also get WATER, which has to be drained away.

In a garage (which suffers from below freezing temperatures here in the American Midwest winters,) a CONDENSING furnace can actually be a bad thing, as you need to make sure that water can drain away and NOT freeze. If it does, that should activate a safety feature, and shut down the furnace, but it could also possibly damage the furnace.

The furnace my dad got was an older NON-condensing model.

Overall, it worked great. We just put a big propane bottle out there and leave it hooked to the furnace. We just use the heat out there when working on a project and then make sure to turn it OFF when not using it. It has a typical, basic thermostat in the shop, and we use that to turn the furnace on and off.

I've been at Daox's place before, and I think it makes perfect sense for him to bury a natural gas line to the garage. It doesn't have to go far, and it will make that space much more useful in the winter.

(Tim, you HAVE insulated the whole thing by now, right?)

The condensing/non-condensing furnace may still be an issue, so make sure to double-check that.

You might also want to take a look at running the chimney through the wall instead of the roof. Walls are easier to fix and less likely to leak than roofs.

AC_Hacker · 11-22-17, 11:47 AM

In Oregon, Natural Gas can be piped underground through plastic, and I think it is HDPE, but it is yellow, or some other color.

However, HDPE is not allowed above ground due to possible physical damage or especially fire.

From a pirate's perspective, PEX makes a dandy gas line. It is sturdy, lasts forever, very easy to work with and cheap. But using it in-house has the stupendous disadvantage that if there was a house fire, the PEX would melt and unleash an inextinguishable fire... bad, bad, bad.

I do remember hearing about problems with physical connectors that were, for a while used to connect from the HDPE gas lines to above ground iron pipe. As I recall, the physical connectors were Shark Bite kind of things, and over time they failed, I suppose because of corrosion.

If I am right, and the NG line is HDPE (not PEX), then it could be fusion-welded to HDPE fittings that are physically designed to accept iron fittings.

This pirate is temporarily using PEX for an in-house gas dryer connection, so it does work.

-AC

10-09-17, 05:23 PM	#1
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Underground natural gas line for garage furnace install? This past weekend I acquired a natural gas furnace from my step father. He had the one in his house replaced since this one was acting up on him. His son used to be a HVAC tech, and said it needed a new regulator valve. Its an older furnace, so he opted to replace it instead of fix it. I figure no problem, I can put one of those in, so he gifted it to me. Now, I'd like to put this furnace out in my garage. I believe the unit is ~40-60k BTU. This means I will need to run a natural gas line probably about 10 feet from the meter to my garage. Is there anything special that I need to know about burying natural gas line? What gas line is rated for underground use? Googling shows a lot of arguing about why this can't be a DIY job. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

10-11-17, 01:36 PM	#4
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Thanks Pinballlooking. Thats very kind of you to offer. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

10-11-17, 02:23 PM	#6
pinballlooking Super Moderator Join Date: Jun 2013 Location: SC Posts: 2,930 Thanks: 172 Thanked 564 Times in 463 Posts	They are very similar to shark bite fittings and they pass code. I did not know anyone with fusion equipment. So compression fitting it was. It held the pressure test fine. __________________ Current project Aquaponics system , Passive Solar Greenhouse build To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Solar Install 12.5 Kwh- To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Mini Split installs - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. EV Chevy Volt - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

11-20-17, 05:09 PM	#8
bennelson Home-Wrecker Join Date: Sep 2008 Location: SE Wisconsin Posts: 546 Thanks: 3 Thanked 165 Times in 96 Posts	My Dad put a natural gas furnace out in his shop, which is attached off the back of the garage. The dog's kennel is also off the back of that building, and there's a small dog door for the animal to get inside to an interior box. The detached garage does NOT have natural gas running to it. There was also a pond, rock garden, and driveway in between the house and the garage, so trenching and burying natural gas pipe to there didn't make sense. He instead converted the furnace to propane. My understanding is that it's pretty easy to do that, it's mostly just an orifice change. Lots of people live outside of towns, where there's no natural gas, and instead have one of those large "pill" propane tanks in their yard. So, there's a lot of gas-to-propane adapter kits out there. The furnace itself is in a "lean-to" area which was originally outdoors, but under the overhang of the garage roof. That area was walled in, but it's still essentially outdoors. The main vent out from the furnace is wrapped in insulation before going into the shop. The other thing to think about here is that the NEW furnaces are CONDENSING. They magically pull out the "latent" heat which means more of the natural gas fuel gets converted to heat (higher efficiency) but that you also get WATER, which has to be drained away. In a garage (which suffers from below freezing temperatures here in the American Midwest winters,) a CONDENSING furnace can actually be a bad thing, as you need to make sure that water can drain away and NOT freeze. If it does, that should activate a safety feature, and shut down the furnace, but it could also possibly damage the furnace. The furnace my dad got was an older NON-condensing model. Overall, it worked great. We just put a big propane bottle out there and leave it hooked to the furnace. We just use the heat out there when working on a project and then make sure to turn it OFF when not using it. It has a typical, basic thermostat in the shop, and we use that to turn the furnace on and off. I've been at Daox's place before, and I think it makes perfect sense for him to bury a natural gas line to the garage. It doesn't have to go far, and it will make that space much more useful in the winter. (Tim, you HAVE insulated the whole thing by now, right?) The condensing/non-condensing furnace may still be an issue, so make sure to double-check that. You might also want to take a look at running the chimney through the wall instead of the roof. Walls are easier to fix and less likely to leak than roofs. __________________ To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

11-22-17, 11:47 AM	#9
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 724 Times in 534 Posts	Natural Gas Lines In Oregon, Natural Gas can be piped underground through plastic, and I think it is HDPE, but it is yellow, or some other color. However, HDPE is not allowed above ground due to possible physical damage or especially fire. From a pirate's perspective, PEX makes a dandy gas line. It is sturdy, lasts forever, very easy to work with and cheap. But using it in-house has the stupendous disadvantage that if there was a house fire, the PEX would melt and unleash an inextinguishable fire... bad, bad, bad. I do remember hearing about problems with physical connectors that were, for a while used to connect from the HDPE gas lines to above ground iron pipe. As I recall, the physical connectors were Shark Bite kind of things, and over time they failed, I suppose because of corrosion. If I am right, and the NG line is HDPE (not PEX), then it could be fusion-welded to HDPE fittings that are physically designed to accept iron fittings. This pirate is temporarily using PEX for an in-house gas dryer connection, so it does work. -AC __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...

10-09-17, 06:40 PM	#2
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,431 Thanks: 431 Thanked 619 Times in 517 Posts	Same basic deal as running a line set for an air conditioner.

10-11-17, 01:53 PM	#5
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,431 Thanks: 431 Thanked 619 Times in 517 Posts	Who said shark bite fittings are not good enough for everything? Cuz that's what the stab fittings look like to me.... I'm sure they're gas industry shark bite fittings.

10-11-17, 11:35 PM	#7
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	What ever you use it has to be to your local code. For example in new Mexico you can not use copper or aluminum line.