1/2" run big enough

[mustangcrazy77]

I'm trying to plan out the routing of my natural gas line from the main run in the house to the heater in the garage. My run from the garage at the tube heater to the nearest junction in the house is 73' with all bends. That particular junction is only 1/2" however and makes a long 20' "U" run to the 1" line which brings the total run of 1/2" to 93'. I could conversely knock almost 20' off of the total if I were to just run directly into the 1" main if it would help much....but I figured it would be better to have the garage heater downstream of the other main appliances (I am only using gas for the furnace though).

Is the 1/2" going to be big enough to support my needs? I already have a schedule 40 line buried connecting the garage to the house which I had planned on pushing some flexible gas-line through...but I had only figured on 1/2" so anything bigger may be waaaay too tight.

The tube heater is a 100,000BTU unit with a min. inlet pressure of 4.5" WC and a manifold pressure of 3.5" WC.

 

[redsky49]

A 1/2" line, 73' in length, at standard design conditions is good for about 36,000 btuh. For 93', capacity is about 32,000 btuh.

You may need to rethink this.

As always, offered only as opinion

 

[mustangcrazy77]

What would happen if I were to oversize the gas line to say...oh, 1 1/4" to the garage?

 

[alexmcneilly]

My friend, who owns his own heating and cooling business, set me up. I am using a 45000BTU Mr Heater in my garage. The line run from house to garage is about 75'. This line is 1". Once it comes into the garage it's reduced to 1/2".
So far so good. That baby really heats up my 720sq ft garage. It also helps that the ceiling, walls and garage door are insulated.

 

[redsky49]

What would happen if I were to oversize the gas line to say...oh, 1 1/4" to the garage?

1" would be satisfactory for a 93' run and the 100 mbh heater you referenced. Check first that you actually require that much heat.

Additionally, this addresses only the garage service pipe size. You will have to confirm that your existing gas service has the capacity to handle the increase in gas consumption. Generally the existing meter is sized so that such a large increase will require a meter reset. A phone call to your utility company will provide that information, as well as street pressures. If undersized, typically the utility will heavy up the service at no additional cost to you.

Make certain that you allow for combustion air and proper venting of the device.

Good luck with your project.

As always, offered only as opinion

 

[mustangcrazy77]

The reason I asked is because someone locally is selling 150' of some wardflex for $150 including fittings. This would cover my whole run without the need for a single break.

As for the demand on the meter...point noted. I will say though the house is plumbed up for all gas appliances and I'm only using it for my main heat and water.

 

[alexmcneilly]

The Wardflex, I assume is CSST? I thought CSST was not good for underground as it was susceptible to exploding if the ground was hit by lightning.

See: http://www.lightning.org/default.ph...lightning&screen_height=652&screen_width=1397

 

[mustangcrazy77]

The Wardflex, I assume is CSST? I thought CSST was not good for underground as it was susceptible to exploding if the ground was hit by lightning.

See: http://www.lightning.org/default.ph...lightning&screen_height=652&screen_width=1397

As long as it's properly grounded to a grounding rod....it's apparently fine.

 

[HoosierBuddy]

Unless you buy a specially jacketed CSST especially made for direct burial, you are supposed to only use CSST in a sleeve, normally S40 PVC. Make sure you obtain and read the manual the manufacturer will make available to obtain certification or qualification before using their pipe and fittings as you will be in violation of the national fuel code if you aren't qualified or certified on that manufactuer's CSST. Be aware that CSST has obtained certifications based on being used as a system and that means it is NEVER acceptable to mix and match differening manufactuerer's fittings and tubing.

REGARDGING GROUNDING OR BONDING...you will need to check the information you receive carefully to verify bonding or grounding requirements. This has been a source of much concern in the CSST market, because of the fire potential due to lightning strikes. I know at least one CSST maker requires all CSST installations be bonded to the main electrical panel with a #6 wire. Other manufacturer's instructions suggest a ground rod. I was talking to a guy from one of the CSST manufactuerers yesterday at some CSST training I attended and he said in the near future all CSST would need to be bonded to the electrical panel to meet code (I think he said NEPA 54...but maybe it was NEPA 58).

Polyethylene gas line has taken over most of the underground gas line market, because it is cheaper, doesn't need to be grounded/bonded and normally wouldn't be sleeved. You can't use it above ground though...so that's where csst or black steel would be needed. You also have to protect CSST from contact from mowing equipment, ect. where it comes out of the ground...and use the available nail protectors if you are running it through studs close to a wall surface. Nail guns and CSST have gotten into it a few times. So far, nail guns remain undefeated in those battles.


Phil

 

[mustangcrazy77]

I inquired with consumers energy and it appears they do not offer the PE lines with risers for the DIY-ER in my area for an add-on run. They also wont come out to make one for me as they apparently don't offer that service in my area.

Soo...I went ahead and picked up some 1 1/4" wardflex.

I bought a few sticks of 2" sch. 40 and buried it ~ 16" underground. I borrowed a friends hot-box to heat up the sch. 40 to make a slight offset to transition from the 90* elbow tied into the underground run. From there the sch. 40 runs right up to where it meets the 3/4" black pipe which is run the rest of the way to the heater. After that, I just had to push the wardflex down through the conduit and pull it out in the crawl space to where I plan on adding the "T". As for the bonding, I'll do it per the manual.

One more question though, is there any problem shutting off the gas on the line before the meter? My house doesn't have a main gas shut-off after the meter...so I planned on hooking one up when I cut a line in half to place a T for the new run.

 

[matt60j]

3/4 " good to go.