I think I screwed up

[smuth10]

I ran a 1\2" gas line out to my new garage for my radiant heat setup and I am pretty sure I need a bigger gas line. Hopefully someone here can tell me for sure. Here are the specs:

Takagii T-H3M-DV-N THWH. 5.0w.c. min and 10.5 wc max
Run is 70-75' from the house. 1-1\4" gas line pretty much up to the exterior wall in the house and then 1\2" to the new garage

I ordered a manometer to test the pressure, but I am pretty sure I am screwed. For some reason I was thinking because the Takagi T-H3M-DV only had a 1\2" inlet and would only run at 30-40k BTU, a 1\2" gas line would be fine. I am worried it will not even turn on if it does not detect enough pressure
Any help would be appreciated.

 

[bigredmf]

I think you are significantly undersized. When I look at that unit it is 120,000 btu.

One option may be to increase your natural gas pressure at the meter but that requires step down regulators at each natural gas appliance you have. Even then I am not sure you can get 120k out of a 1/2" line.

Note I am not a expert in this field but have investigated this previously.

Note my radiant setup runs on a 26k btu hot water tank though it only covers roughly 625 ft2 of my basement.

Thank you

Red

 

[bigredmf]

Kind of strange that the specs read

Overview

The T-H3M-DV-N is a new breed of tankless for smaller spaces. This model also uses existing 1/2" gas supply lines and inexpensive PVC venting to lower installation costs.

The T-H3M supplies hot water to domestic hot water systems (directly or indirectly) which can be used with storage tanks, recirculation systems, hydronic heating systems, radiant floor systems, and/or domestic & heating applications.

 

[Shiftless]

I ran a 1\2" gas line out to my new garage for my radiant heat setup and I am pretty sure I need a bigger gas line. Hopefully someone here can tell me for sure. Here are the specs:

Takagii T-H3M-DV-N THWH. 5.0w.c. min and 10.5 wc max
Run is 70-75' from the house. 1-1\4" gas line pretty much up to the exterior wall in the house and then 1\2" to the new garage

I ordered a manometer to test the pressure, but I am pretty sure I am screwed. For some reason I was thinking because the Takagi T-H3M-DV only had a 1\2" inlet and would only run at 30-40k BTU, a 1\2" gas line would be fine. I am worried it will not even turn on if it does not detect enough pressure
Any help would be appreciated.

Sorry to hear about that mistake.
If you test the static pressure with nothing on in the garage, it will probably read an acceptable value. The problem is that once your heater starts up, the pressure will be less due to the pressure drop in the undersized pipe. If it was shorter than your 75 feet you might get by. But that is irrelevant.

I guess there is a moral to that story

 

[smuth10]

Kind of strange that the specs read

Overview

The T-H3M-DV-N is a new breed of tankless for smaller spaces. This model also uses existing 1/2" gas supply lines and inexpensive PVC venting to lower installation costs.

The T-H3M supplies hot water to domestic hot water systems (directly or indirectly) which can be used with storage tanks, recirculation systems, hydronic heating systems, radiant floor systems, and/or domestic & heating applications.

I know, but I still should have done more research on the size of the line. Just too much going on at the time and I thought I was good.

 

[smuth10]

Sorry to hear about that mistake.
If you test the static pressure with nothing on in the garage, it will probably read an acceptable value. The problem is that once your heater starts up, the pressure will be less due to the pressure drop in the undersized pipe. If it was shorter than your 75 feet you might get by. But that is irrelevant.

I guess there is a moral to that story

HMM. Sounds like I am digging a new trench.

I just ordered a 1" CSST line and fittings. Don't want to have to do this again. Wish there was an icon for me kicking myself in my own ***

 

[CNGsaves]

HMM. Sounds like I am digging a new trench.

I just ordered a 1" CSST line and fittings. Don't want to have to do this again. Wish there was an icon for me kicking myself in my own ***.

Too little information . . . . . what is your PRESSURE for Natural Gas supply ??

If it's typical residential 7 to 10 in water column (around 1/2 psi) then YES you're surely screwed leaving it as is. Only cure would be request different regulator/meter from gas company and upgrade to 2 psi (high pressure) and immediately supply the garage from T after the meter. Then install another regulator to step down pressure for house like it was previously.

At 70 to 75 feet for 120K Btu . . . and only 1/2 psi you will need LARGE supply line of NG out to garage . . . more accurately I should say HUGE !!!!

GJ guru's will likely chime in soon but my layman's review of the chart shows you should really have 2 1/2 inch buried yellow polyethylene plastic pipe for that 75 ft run to handle 120K Btu.
EDIT: Calc error on my part so OP likely might need 1 1/2" instead.

I'd be making call to Gas Company and beg them for help !! Basically you might be FORCED to get new NG meter/regulator as typical residential meter won't even handle your now VASTLY INCREASED DEMAND for NG (ie both for house and now 120K Btu for garage) that will EXCEED the capability of the meter. STOP all work and figure this out with GasCo help.

OP . . . if you're thinking about using CSST buried in ground for that 75 feet, you are BADLY mistaken again. It is WRONG product. You NEED to be using the YELLOW polyethylene plastic pipe just like the gas company uses with risers on each end.

 

[smuth10]

Too little information . . . . . what is your PRESSURE for Natural Gas supply ??

It it's typical residential 7 to 10 in water column (around 1/2 psi) then YES you're likely screwed leaving it as is. Only cure would be request different regulator/meter from gas company and upgrade to 2 psi (high pressure) and immediately supply the garage from T after the meter. Then install another regulator to step down pressure for house like it was previously.

At 70 to 75 feet for 120K Btu . . . and only 1/2 psi you will need LARGE supply line of NG out to garage . . . more accurately I should say HUGE !!!!

GJ guru's will likely chime in soon but my layman's review of the chart shows you should really have 2 1/2 inch buried yellow polyethylene plastic pipe for that 75 ft run to handle 120K Btu.

I'd be making call to Gas Company and beg them for help !!

According to that chart a 1" line would give me 149,000 BTU's. According to the chart in the Takagi manual, I would need a 3\4" line. Not sure which is correct, but I will be safe with a 1" I would think.

 

[CNGsaves]

You're forgetting any FITTINGS that also add 5 ft to the calculation. Also, I doubt your current connection is close enough to meter, so you are starving the flow to garage with path that NG needs to take throughout the house.

Finally, the meter itself might NOT flow that much NG once you get full load of house (furnace, water heater, stove, dryer) . . PLUS . . . the new load of 120K Btu out the 75 ft to the garage. What is your GRAND TOTAL NG DEMAND of all NG appliances ??

You NEED to consult a professional. STOP all work until you figure it out.

Finally . . no CSST . . . NO, NO, NO !!! You want yellow plastic NG pipe with risers on each end. You'll be thanking me for this recommendation.

EDIT: I made calc error so likely 1 1/2" would handle the 120K Btu demand at 75 ft to garage . . . IF . . the meter would even flow it (which you'll want to double check with GasCo). OP you need to call the GasCo and get some accurate information and do this right.

Here is good explanation of what all you need to consider when sizing that long buried NG run out to garage for 120K Btu demand. The same problem comes up when adding a large NG generator.
http://www.uscarb.com/natural-gas-chart.htm

 

[Kamn]

The chart I just looked at showed a 1-1/2" line for that supply run of 75'

I have an 80,000 btu heater in my garage and it called for 1-1/2" at 110' long

Use the yellow PE pipe

And what he said^^^^ about calling your NG supplier to make sure your meter can handle that much.....you may need to be upsized

 

[smuth10]

Thank you guys for the heads up. I will call them in the morning to see what they say.
BTW, an online calculator I found says I would only have approx 22,000 BTU's at the garage for the 120k HWH. What an idiot I am

Why are you guys against the CSST pipe?

 

[smuth10]

The chart I just looked at showed a 1-1/2" line for that supply run of 75'

I have an 80,000 btu heater in my garage and it called for 1-1/2" at 110' long

Use the yellow PE pipe

And what he said^^^^ about calling your NG supplier to make sure your meter can handle that much.....you may need to be upsized

What chart are you looking at? I would really like to figure this out myself if I can. I am starting to think about an electric THWH. LOL

 

[smuth10]

CNG:
FWIW I have an 1-1\4" line running from the meter to approx 33' across the basement with one elbow and 16' of 3\4" line from there to the farthest appliance.

I rounded up to 50' and at an 1-1\4" line, according to the chart, I have approx 588 total CFH available.
Total appliance load is approx 275 CFH.
If I am reading that page correctly I should have 313 CFH or 313,000 BTU's available, but I am assuming this depends on the size of the line I run out there.
According to the bottom chart a 1" line at 80' would bring 222CFH to the appliance. That is not factoring in the fittings, but I would think I would still have plenty to run a 120k HWH.

I just want to make sure I am reading this correct. Still going to consult a few pro's tomorrow. I may just trench the new line myself and have them do the install.

Thanks again for your help, Scott

 

[mygarageone]

CNG:
FWIW I have an 1-1\4" line running from the meter to approx 33' across the basement with one elbow and 16' of 3\4" line from there to the farthest appliance.

I rounded up to 50' and at an 1-1\4" line, according to the chart, I have approx 588 total CFH available.
Total appliance load is approx 275 CFH.
If I am reading that page correctly I should have 313 CFH or 313,000 BTU's available, but I am assuming this depends on the size of the line I run out there.
According to the bottom chart a 1" line at 80' would bring 222CFH to the appliance. That is not factoring in the fittings, but I would think I would still have plenty to run a 120k HWH.

I just want to make sure I am reading this correct. Still going to consult a few pro's tomorrow. I may just trench the new line myself and have them do the install.

Thanks again for your help, Scott

No matter which way you slice it , 1/2"" way to small . You will need a min of 1" and best would be 11/4" . The gas company won't increase pressure for you , at least not for what your doing.

 

[zmaxmotorsports]

I ran a 1\2" gas line out to my new garage for my radiant heat setup and I am pretty sure I need a bigger gas line. Hopefully someone here can tell me for sure. Here are the specs:

Takagii T-H3M-DV-N THWH. 5.0w.c. min and 10.5 wc max
Run is 70-75' from the house. 1-1\4" gas line pretty much up to the exterior wall in the house and then 1\2" to the new garage

I ordered a manometer to test the pressure, but I am pretty sure I am screwed. For some reason I was thinking because the Takagi T-H3M-DV only had a 1\2" inlet and would only run at 30-40k BTU, a 1\2" gas line would be fine. I am worried it will not even turn on if it does not detect enough pressure
Any help would be appreciated.

How big is the garage/shop?

 

[smuth10]

How big is the garage/shop?

1200 sq\ft. 30 x 40

After screwing this up I have seriously considered putting in an electric HWH, as I have a new 200 amp panel in there, but I know the gas hwh will save a lot of money in the long run

 

[mygarageone]

1200 sq\ft. 30 x 40

After screwing this up I have seriously considered putting in an electric HWH, as I have a new 200 amp panel in there, but I know the gas hwh will save a lot of money in the long run

Unless you want to pay for hi elec costs sooner. Than later( thanks to the EPA )
Just run a new gas line . It will be well worth the effort !

 

[goneflyin2002]

Sounds like too much heater for that space, but that all depends on your insulation etc etc.
My 2000' shop runs with 80-90 Kbtu and it takes a dead cold day to make it use all the btus.
I think it has a 1" line running 130' for ref.

thx

 

[venturesomerite]

My work shop has a gas heater, it is fed by 1.5" black iron pipe (inside) and is roughly 200-250' from the meter. I don't know BTU on the heater, but the shop is 25'x43'x18 'sloping to 25'

I only rent it, so all I care is that the heater works, which it does.

 

[brewchief]

Why are you guys against the CSST pipe?

None of the CSST pipe I am familiar with is approved for direct bury, it can be run underground but must be inside conduit and the conduit must come out of the ground outside and be vented so a gas leak cannot get to the inside of the building.

FWIW Trac-pipe does make a direct bury CSST product that basically already has a flexible conduit on the outside of it.

CSST is also more restrictive due to it's ridged design so it may need to be larger then other piping types to flow the same amount of gas.

Nothing wrong with using CSST but this just isn't the ideal use for it, poly pipe and risers would be my choice for this job.

 

[CNGsaves]

OP . . . What would distance be . . IF . . you T'd off NG service immediately after the meter and bury the yellow plastic pipe around house to garage?? Where is meter in comparison to your shop ?? Are you "forced" to go through house for your connection to the shop ?? How feasible would it be to Upsize feeder black pipe steel to 2" within the house ?? If not, then the OVERsizing of buried line to shop may overcome this - - ie go BIG with 1 1/2" or 2" or whatever the GasCo recommends . . . hopefully not 2 1/2" for my first wild guess !!

Sorry if I might have scared you with the 2 1/2" guess, but worst case scenario 1 1/2" or 2" is possible. GJ boiler guy guru's will chime in and clarify. Pretty sure I was Wrong with my calcs by factor of ten in that first guess . . . so 1 1/2" might be more accurate - - - so again sorry for the scare and my screwup !!

Below is screenshot of your Takagii T-H3M-DV-N tankless heater according to the manufacturer's website.
http://www.takagi.com/products/tankless-water-heaters/t-h3m-dv-n

Clearly it is 120K Btu so at peak demand it WILL be drawing a lot of NG and you'll want plenty of pipe/flow feeding that tankless. Have no idea why they'd put 1/2" fittings on unit but clearly in ANY install you'd run oversize NG lines when only dealing with low pressure residential setup. Thus, you'd run LARGE pipe all the way then step down to 1/2" at heater.

Yellow plastic PE pipe is cheap at around 55 cents a foot (smaller sizes - - so maybe $1 ft for large), and you'll have maybe $80 to $120 at each end for risers (transition from plastic to steel) along with Stablock connector and shutoff. Worse case you might have $400 to $500 in materials to bury your NG line properly for 75 feet. Once above grade, you'd enter building and use large black pipe steel all the way to heater.

Do not consider electric for radiant heat in garage after you've set everything up for NG. The NG will be cheaper option long-term. You can get this figured out with right help from the pro's and GasCo. Good luck.

 

[smuth10]

None of the CSST pipe I am familiar with is approved for direct bury, it can be run underground but must be inside conduit and the conduit must come out of the ground outside and be vented so a gas leak cannot get to the inside of the building.

FWIW Trac-pipe does make a direct bury CSST product that basically already has a flexible conduit on the outside of it.

CSST is also more restrictive due to it's ridged design so it may need to be larger then other piping types to flow the same amount of gas.

Nothing wrong with using CSST but this just isn't the ideal use for it, poly pipe and risers would be my choice for this job.

Brewchief

I read all of the guidelines for the CSST and did run it in conduit with a small airspace at the fittings per the the instructions. That being said, I think I am going to use the PE for the new run. Just makes sense i think

 

[smuth10]

OP . . . What would distance be . . IF . . you T'd off NG service immediately after the meter and bury the yellow plastic pipe around house to garage?? Where is meter in comparison to your shop ?? Are you "forced" to go through house for your connection to the shop ?? How feasible would it be to Upsize feeder black pipe steel to 2" within the house ?? If not, then the OVERsizing of buried line to shop may overcome this - - ie go BIG with 1 1/2" or 2" or whatever the GasCo recommends . . . hopefully not 2 1/2" for my first wild guess !!

Sorry if I might have scared you with the 2 1/2" guess, but worst case scenario 1 1/2" or 2" is possible. GJ boiler guy guru's will chime in and clarify. Pretty sure I was Wrong with my calcs by factor of ten in that first guess . . . so 1 1/2" might be more accurate - - - so again sorry for the scare and my screwup !!

Below is screenshot of your Takagii T-H3M-DV-N tankless heater according to the manufacturer's website.
http://www.takagi.com/products/tankless-water-heaters/t-h3m-dv-n

Clearly it is 120K Btu so at peak demand it WILL be drawing a lot of NG and you'll want plenty of pipe/flow feeding that tankless. Have no idea why they'd put 1/2" fittings on unit but clearly in ANY install you'd run oversize NG lines when only dealing with low pressure residential setup. Thus, you'd run LARGE pipe all the way then step down to 1/2" at heater.

Yellow plastic PE pipe is cheap at around 55 cents a foot (smaller sizes - - so maybe $1 ft for large), and you'll have maybe $80 to $120 at each end for risers (transition from plastic to steel) along with Stablock connector and shutoff. Worse case you might have $400 to $500 in materials to bury your NG line properly for 75 feet. Once above grade, you'd enter building and use large black pipe steel all the way to heater.

Do not consider electric for radiant heat in garage after you've set everything up for NG. The NG will be cheaper option long-term. You can get this figured out with right help from the pro's and GasCo. Good luck.

CNG

First, thank you for all of your help, much appreciated. I cannot run right from the meter as I would need to tear up a portion of the driveway and to run around the other side of the house would be a 400'+ run.

I talked with a friend of a friend tonight and he walked me through what I should have done in the first place. He is an HVAC guy and has a lot of experience. He calculated it out for me and said I could run up to 100' from the house with the Endot PE 1.315 OD pipe and be good with my 120k burner. I would have to come right off of the 1-1\4" main line in the basement to accomplish this, but it comes right to the back wall of the basement where I need to be. Just a lot of pipe work. He also said, as many of you have, that I would need to contact the gas company and make sure my meter was big enough to feed all of my appliances and the new heater.

I am going to order 150' of the PE pipe with the risers and connectors, run the new trench and he is going to do everything else for me. I like doing things myself, but realize now I should have hired this part out. Live and learn I guess. I will sleep well knowing this is done right. Thanks again for everyone's help!

 

[Showkey]

Might be a good idea for that HVAC guy run a heat loss calculation...........as others have questioned 120,000 might not be "right sized".

 

[CNGsaves]

OP . . . good to hear you've local guru helping you with pipe sizing and the connections. Sounds like size of 1 1/4" yellow PE pipe is what you've settled on.

Did your HVAC guy find you wholesale supplier to get the PE pipe cheap and the risers, Stablock connectors, shutoffs ?? What pricing did you get on each ??

If it were me, I'd go with 1 1/2" just to add extra capacity. I've got 1" for my 25 feet to garage . . . but . . that will also cover Natural Gas compressor (3600 psi) that will fill my vehicle with CNG !!

 

[smuth10]

Might be a good idea for that HVAC guy run a heat loss calculation...........as others have questioned 120,000 might not be "right sized".

I haven't ordered anything yet so I will definitely ask him about it. From what I saw on the Takagi website, the 120,000 unit was the smallest condensing hwh they have that was approved for use in a radiant floor system.

I used an online calculator and it said I needed 15,000 BTU's\Hr. Not sure how I would ever buy such a small condensing HWH. I was under the impression the one I was looking at would never actually run at 120k, as it would never need to. Not really sure

 

[goneflyin2002]

Can you at least use the old line for something else, like water or air?

 

[smuth10]

Can you at least use the old line for something else, like water or air?

I was planning on putting together a small outdoor kitchen next year so I am going to use the line, or at least part of it, for the grill.

I hadn't thought about water, but that is a good idea. Not sure if CSST would work for that tho, would it?

 

[smuth10]

Did your HVAC guy find you wholesale supplier to get the PE pipe cheap and the risers, Stablock connectors, shutoffs ?? What pricing did you get on each ??

Where did you buy your materials? This place seems to have great prices

http://www.hdpesupply.com/mdpe-gas-pipe-coils/?sort=priceasc

 

[mygarageone]

I haven't ordered anything yet so I will definitely ask him about it. From what I saw on the Takagi website, the 120,000 unit was the smallest condensing hwh they have that was approved for use in a radiant floor system.

I used an online calculator and it said I needed 15,000 BTU's\Hr. Not sure how I would ever buy such a small condensing HWH. I was under the impression the one I was looking at would never actually run at 120k, as it would never need to. Not really sure

There are units out there as low as 65,000 btu's . With such a low demand , I certainly would look into a Takagi on demand water htr . Non condensing .

I have 2 , one for the shop and one for the house . Going on 4 yrs and not a lick of problems ,
Yea I know about the they won't work comments . Well guess what , properly installed they do work .
Here's the deal I paid $600 each and a normal condensing boiler would have cost me at the least $ 1900.00 ea. The Takagis run around 85 % .

If I get only 6-7 yrs out of them , I'm money way ahead . But I know of units that are going on 10 yrs from installations in Wisconsin .
Takagi makes a dam good unit and they have rated it for radiant heat.

So that's were I'm at on these things.

 

[smuth10]

There are units out there as low as 65,000 btu's . With such a low demand , I certainly would look into a Takagi on demand water htr . Non condensing .

I have 2 , one for the shop and one for the house . Going on 4 yrs and not a lick of problems ,
Yea I know about the they won't work comments . Well guess what , properly installed they do work .
Here's the deal I paid $600 each and a normal condensing boiler would have cost me at the least $ 1900.00 ea. The Takagis run around 85 % .

If I get only 6-7 yrs out of them , I'm money way ahead . But I know of units that are going on 10 yrs from installations in Wisconsin .
Takagi makes a dam good unit and they have rated it for radiant heat.

So that's were I'm at on these things.

I tend to agree with you for the most part, but the smallest standard hwh I see is the jr and even that one is 140k BTU. It is $500-600 online and the condensing is only $750. Just made sense to me to spend the little extra and it only required 120k btu. Which model are you referring to that only requires 65k btu?

 

[mygarageone]

I tend to agree with you for the most part, but the smallest standard hwh I see is the jr and even that one is 140k BTU. It is $500-600 online and the condensing is only $750. Just made sense to me to spend the little extra and it only required 120k btu. Which model are you referring to that only requires 65k btu?

Triangle Tube makes a 65,000 condensing unit , how ever it costs $1900.

I had no idea Takagi had a cond unit that cheap .

 

[smuth10]

This is the one I was looking at buying:
http://www.takagi.com/products/tankless-water-heaters/t-h3m-dv-n

Supplyhouse.com
http://www.supplyhouse.com/Takagi-T...9On1tcaylUag-XNd_uUQ0GFzoOJ5FRUXWQaAvqq8P8HAQ

What do you think of this one?
http://www.zoro.com/bosch-tankless-...q-5MB__toBQad_GadVFgwaAv5T8P8HAQ&gclsrc=aw.ds

 

[mygarageone]

This is the one I was looking at buying:
http://www.takagi.com/products/tankless-water-heaters/t-h3m-dv-n

Supplyhouse.com
http://www.supplyhouse.com/Takagi-T...9On1tcaylUag-XNd_uUQ0GFzoOJ5FRUXWQaAvqq8P8HAQ

What do you think of this one?
http://www.zoro.com/bosch-tankless-...q-5MB__toBQad_GadVFgwaAv5T8P8HAQ&gclsrc=aw.ds

Stay away from Bosch period !

Now my opinion , with such a low btu demand , your heating unit will be on low fire 90 % of the time , which is what you want from cond units.
But given the complexity of a condensing boiler . I personal would lean towards the Takagi Jr. Non condensing . Is the savings you see with a cond unit over the non worth the xtra trouble you may see down the road , your call there.

But one thing I would certainly do is a net search on customer reviews , that should help you.
Caution , I have learned that many if not most negative cust reviews on equipment are do to the customers own neglect on proper installation of reviewed products.
They want to bad mouth the equipment for there improper installation !

I know this , I have installed several Takagi units along with several other contractors and there are no real issue that I have experienced or heard of.

 

[JimL]

We always just bump them up to 2lb systems. Then you can run 3/4 a long dang way.

 

[smuth10]

We always just bump them up to 2lb systems. Then you can run 3/4 a long dang way.

From what other people are saying the gas company will not accommodate this, no? Maybe I am misunderstanding what you are saying.

 

[cjc2160]

To the op,

I purchased and installed the same Takagi 120,000 btu unit you are looking at. It's only been running a month or so but it hasn't missed a beat, i am heating over 1900 sq'. Time will tell.

 

[mygarageone]

From what other people are saying the gas company will not accommodate this, no? Maybe I am misunderstanding what you are saying.

They will not bump up pressure for residential , it take a lot to get commercial pressure bumped . We had to totally repipe a Walmart because they wouldn't bump pressure up. Walmart being the big bad corporate bully Paid us twice to gas pipe a brand new store . Once for a high pressure gas line They figured they would push through and then when the gas company said no . We pulled all of the steel pipe and installed a 6" welded main to accommodate low pressure gas .
This cost Walmart a heck of a lot of money because we had to make the change in Feb . Gas company would not budge .

 

[CNGsaves]

Where did you buy your materials? This place seems to have great prices

http://www.hdpesupply.com/mdpe-gas-pipe-coils/?sort=priceasc

Those prices are pretty good for the pipe if you can pickup in person, but with shipping not so much. Also, doesn't look like they will sell you small quantity of 1 1/2" pipe which is what I'd recommend.

Prices for risers and Constab connectors are too high IMHO. I got much better pricing from wholesale supplier Groebner & Assoc in Kansas City area. I think you should do more checking around for wholesale supplier in your area.

See post # 12 of this thread where I posted details of my prices for 1" supplies. I drove 3 hours with utility trailer to pick up all my materials.
http://www.garagejournal.com/forum/showthread.php?t=264776&highlight=kansas+city+riser

See also this thread by fellow GJer . . Madosta . . in Michigan who put in yellow PE pipe recently. He might have supplier for you to consider.
http://www.garagejournal.com/forum/showthread.php?t=265153&highlight=kansas+city+riser

CRITICAL thing to make sure you get . . . SAME sizing of pipe and risers. Most common for residential use is . . . IPS . . . . Iron Pipe Size. This is thick wall pipe.

 

[James-W]

Having a 120,000 BTU heater sounds like overkill to me. I have a 24X36 garage with R-19 insulation in the walls and R-30 in the ceiling. I have a 60,000 BTU Hot Dawg natural gas heater and that size is plenty big for my garage.