PEX or PEX-AL-PEX for Outdoor Wood Boilers and how to insulate

[Poston5]

I have purchased a Hardy H2 and now I need to determine which water lines to use. I have read some about it but would like some more input on Pex vrs. Pex-al-Pex. The perks of using Pex is the price, but it expands as it is heated. Pex-al-Pex is more expensive but easier to use and i would think is a stronger product due to the aluminum that is inside, but i have heard about some of it failing over time due to it having multiple different layers. Also if you are using Pex-al-Pex which brand did you choose (i read about some issues on Kitec)?

As for insulating and installing it....i plan to use SDR-35 sewer pipe since it is water tight, and i plan to put the 4 lines together and then install the pipe insulation sleeve around all of them. I want to be able to remove the lines/boiler and move to the next house so spray foam is out of the question for me.

Tell me your thoughts.

 

[taskswap]

I have purchased a Hardy H2 and now I need to determine which water lines to use. I have read some about it but would like some more input on Pex vrs. Pex-al-Pex. The perks of using Pex is the price, but it expands as it is heated. Pex-al-Pex is more expensive but easier to use and i would think is a stronger product due to the aluminum that is inside, but i have heard about some of it failing over time due to it having multiple different layers. Also if you are using Pex-al-Pex which brand did you choose (i read about some issues on Kitec)?

As for insulating and installing it....i plan to use SDR-35 sewer pipe since it is water tight, and i plan to put the 4 lines together and then install the pipe insulation sleeve around all of them. I want to be able to remove the lines/boiler and move to the next house so spray foam is out of the question for me.

It sounds like you're a lot more informed than most so whatever you decide you're probably going to be fine. I went with standard PEX for my installation (make sure you get the oxygen-barrier though) and was generally happy with it, although I ended up redoing everything around the boiler itself in copper to make a neater, stronger installation. I don't know what specific brand it is, but it's whatever pexsupply.com sells as their red, Oxygen-barrier version. They only have one - Rifeng, I think.

I like the sewer pipe idea. Maybe you could use vermiculite as temporary insulation? It does a fair job, it's not too expensive, and you can suck it out with a shopvac and bag it up when you move. Plus it drains well so whatever moisture does end up there won't cause trouble.

 

[hunter h]

pex

I have purchased a Hardy H2 and now I need to determine which water lines to use. I have read some about it but would like some more input on Pex vrs. Pex-al-Pex. The perks of using Pex is the price, but it expands as it is heated. Pex-al-Pex is more expensive but easier to use and i would think is a stronger product due to the aluminum that is inside, but i have heard about some of it failing over time due to it having multiple different layers. Also if you are using Pex-al-Pex which brand did you choose (i read about some issues on Kitec)?

As for insulating and installing it....i plan to use SDR-35 sewer pipe since it is water tight, and i plan to put the 4 lines together and then install the pipe insulation sleeve around all of them. I want to be able to remove the lines/boiler and move to the next house so spray foam is out of the question for me.

Tell me your thoughts.

I used Pex on mine and have had no problems. I know of 4 others that were installed the same way and they have had no problems. I insulated mine and buried it. When we installed one for one of my brothers we insulated each line and then ran them inside 6 inch pipe. Even with it back filled you could still pull the lines back and forth so I would think you could do the same thing and just pull the lines out when you are done and leave the pipe when you move. When you re install just get some new pipe it would not be that expensive. When you install yours you may want to think about a couple things. I installed a frost free water valve on the side of mine to give me another place to hook up a hose since I was running domestic water to it any way. I also installed a weather prof electric out let on the side.

 

[dave_dj1]

I used Pex on mine and have had no problems. I know of 4 others that were installed the same way and they have had no problems. I insulated mine and buried it. When we installed one for one of my brothers we insulated each line and then ran them inside 6 inch pipe. Even with it back filled you could still pull the lines back and forth so I would think you could do the same thing and just pull the lines out when you are done and leave the pipe when you move. When you re install just get some new pipe it would not be that expensive. When you install yours you may want to think about a couple things. I installed a frost free water valve on the side of mine to give me another place to hook up a hose since I was running domestic water to it any way. I also installed a weather prof electric out let on the side.

Why 4 lines? I think you need a special tool to work with the pex-al-pex, at least the plumbers I've seen on jobs do.
I know you will get rattled here about just buying the central pex or similar all insulated, they say it is the best.
I know one thing, you don't want your 4 lines touching each other, the hot will transfer to the colder returns and vice a versa.
If your wanting to get your domestic off the system, most just use a water to water heat ex changer or sidearm in the heat system.

 

[AIM]

Regular pex from Menards or Lowes works just fine.

4 lines in one pipe??? You have fun with that one.

 

[Iska3]

How far is you OWB from your house? What is your water table in the area? How many times do you want to redo your lines?

I have purchased a Hardy H2 and now I need to determine which water lines to use. I have read some about it but would like some more input on Pex vrs. Pex-al-Pex. The perks of using Pex is the price, but it expands as it is heated. Pex-al-Pex is more expensive but easier to use and i would think is a stronger product due to the aluminum that is inside, but i have heard about some of it failing over time due to it having multiple different layers. Also if you are using Pex-al-Pex which brand did you choose (i read about some issues on Kitec)?

As for insulating and installing it....i plan to use SDR-35 sewer pipe since it is water tight, and i plan to put the 4 lines together and then install the pipe insulation sleeve around all of them. I want to be able to remove the lines/boiler and move to the next house so spray foam is out of the question for me.

Tell me your thoughts.

 

[greendohn]

I ran standard pex thru insulated 4 inch pvc. The dealer who sold me the owb carried the stuff and it works pretty well.

 

[jh35]

I have purchased a Hardy H2 and now I need to determine which water lines to use. I have read some about it but would like some more input on Pex vrs. Pex-al-Pex. The perks of using Pex is the price, but it expands as it is heated. Pex-al-Pex is more expensive but easier to use and i would think is a stronger product due to the aluminum that is inside, but i have heard about some of it failing over time due to it having multiple different layers. Also if you are using Pex-al-Pex which brand did you choose (i read about some issues on Kitec)?

As for insulating and installing it....i plan to use SDR-35 sewer pipe since it is water tight, and i plan to put the 4 lines together and then install the pipe insulation sleeve around all of them. I want to be able to remove the lines/boiler and move to the next house so spray foam is out of the question for me.

Tell me your thoughts.

My local Heatmor dealer sells the Kitec with wrapped insulation which I did not want. He pushed he virtues of the Kitec pretty hard. I went with the Thermopex from Central Boiler for the foam insulation. I spent 11USD/ft but am only doing that one time.

I wasn't thinking about moving it like you are however. I've just heard too many people do it the cheap way and regret it. A neighbor has gone cheap at least twice now and usually has a spot by his shop where snow will not accumulate.

Another neighbor has a 200' run of Thermopex and only loses about 1 deg F from the stove to the house. That's what sold me on it. FIL has the Logstor version of what I have. That was priced at 12USD/ft local to me last summer.

Good luck and let us know how things went.

Jeff

 

[Marc]

It sounds like you're a lot more informed than most so whatever you decide you're probably going to be fine. I went with standard PEX for my installation (make sure you get the oxygen-barrier though) and was generally happy with it, although I ended up redoing everything around the boiler itself in copper to make a neater, stronger installation. I don't know what specific brand it is, but it's whatever pexsupply.com sells as their red, Oxygen-barrier version. They only have one - Rifeng, I think.

I like the sewer pipe idea. Maybe you could use vermiculite as temporary insulation? It does a fair job, it's not too expensive, and you can suck it out with a shopvac and bag it up when you move. Plus it drains well so whatever moisture does end up there won't cause trouble.

Why is O[SUB]2[/SUB] barrier PEX necessary for an open loop OWB?

 

[taskswap]

Why is O[SUB]2[/SUB] barrier PEX necessary for an open loop OWB?

You're right, it's not required for open loop. But when I read the Hardy H2 installation manual when responding to the first post:
http://www.hardyheater.com/Pdf/H2H4manual Screen Copy.pdf

The plumbing diagram on page 23 calls for a direct connection to a hydronic system, and it has a T&P valve. It doesn't appear to be open-loop. Unless I missed something or the original poster has a nonstandard setup, this is a closed-loop installation.

 

[beerman6]

When I installed my OWB I used what the dealer had.It was Kitec inside a black plastic pipe with styrofoam insulation around that and covered with a long vis-queen like "sock".

I buried it at 4' and it worked ok for 2 seasons but then I started noticing the snow melting where the pipe was buried. started using more wood than before.

My OWB is not far from the house so 2 years ago I built a box...a above the ground insulated box with standard pex in it.

When I shut it down in the spring I undo the lines,wheel the box to the barn and store it up in the rafters.

Last winter was a weird one and I hardly used any wood at all,but this one is a bit more "normal" and so far I'm VERY happy with the amount of wood burned so far.

 

[mybowtie]

When I installed my OWB I used what the dealer had.It was Kitec inside a black plastic pipe with styrofoam insulation around that and covered with a long vis-queen like "sock".

I buried it at 4' and it worked ok for 2 seasons but then I started noticing the snow melting where the pipe was buried. started using more wood than before.

My OWB is not far from the house so 2 years ago I built a box...a above the ground insulated box with standard pex in it.

When I shut it down in the spring I undo the lines,wheel the box to the barn and store it up in the rafters.

Last winter was a weird one and I hardly used any wood at all,but this one is a bit more "normal" and so far I'm VERY happy with the amount of wood burned so far.

I like this idea...What did you insulate the box with? Did u use quick disconects??

 

[beerman6]

shark bites on both ends.

The pex has the standard black foam sleeves on them,the box is lined with 1" foam and then some R-30(I think) pink stuff.

I wrap the outside with black vis-queen.It has snow sitting on it right now and will until the sun hits it.

 

[jh35]

shark bites on both ends.

.........

I used the Sharkbites too. My first Pex experience. They are not cheap but again I'm only buying them once.

I like your above ground idea too. I think my wife would have a fit, but it would be handy if you were going to move.

 

[taskswap]

I used the Sharkbites too. My first Pex experience. They are not cheap but again I'm only buying them once.

I like your above ground idea too. I think my wife would have a fit, but it would be handy if you were going to move.

I love SharkBites, but if you're going to repeatedly use/remove them one word of warning, after several "cycles" you might want to clip off a half inch of the end of the pipe. The SharkBites do bite into the end a bit, and while the fitting is completely reusable I don't think they meant for the pipe to be 100% reusable. I've had a leaky joint or two over the years where I disconnected/reconnected things. Clipping off the end to create a clean joint always solved the problem.

Never had one completely fail - just a bit of a drip. Hardly an emergency, but might be worth knowing.

 

[beerman6]

:msp_thumbup:

 

[hunter h]

Why 4 lines? I think you need a special tool to work with the pex-al-pex, at least the plumbers I've seen on jobs do.
I know you will get rattled here about just buying the central pex or similar all insulated, they say it is the best.
I know one thing, you don't want your 4 lines touching each other, the hot will transfer to the colder returns and vice a versa.
If your wanting to get your domestic off the system, most just use a water to water heat ex changer or sidearm in the heat system.

Yes 4 lines 1hot water supply for heat 1 hot water return for heat. The hardy domestic heat exchanger is in the top of the boiler so you have a supply and return for that that makes 4 lines. The lines are insulated each with rubber tex and then put inside of a 6 inch drain pipe. yes all 4 will fit. Rubbertex thin wall pipe insullation gives you more room. the lines do not touch each other. You will need the crimping tool if you use the pex fittings. If you do not have one or want to buy one you can rent one to use for a day to do the install.

 

[Jon B.]

I heat domestic hot water, the house and the garage with my OWB. The exchangers, though, are in series, and in that order. Water heater has a side-arm exchanger. The house and garage are water-to-air exchangers; a coil in the furnace plenum and a forced-air heater hanging from the garage ceiling.

Central Boiler recommends this, in fact, so I followed their instructions. I haven't yet measured the temperature drop at each exchanger but we have an infrared thermometer at work that I'll bring home to check each exchanger, as well as the overall drop right at the boiler outlet and return inlet.

Jon

 

[jh35]

I heat domestic hot water, the house and the garage with my OWB. The exchangers, though, are in series, and in that order. Water heater has a side-arm exchanger. The house and garage are water-to-air exchangers; a coil in the furnace plenum and a forced-air heater hanging from the garage ceiling.

Central Boiler recommends this, in fact, so I followed their instructions. I haven't yet measured the temperature drop at each exchanger but we have an infrared thermometer at work that I'll bring home to check each exchanger, as well as the overall drop right at the boiler outlet and return inlet.

Jon

I have a Heatmor, but in series just like you describe. My house is about 1000 sq ft and I have a teenage daughter so I hooked the sidearm ahead of the furnace. My main concern was with the hot water demand. 2 months in and no problems.

 

[dave_dj1]

Yes 4 lines 1hot water supply for heat 1 hot water return for heat. The hardy domestic heat exchanger is in the top of the boiler so you have a supply and return for that that makes 4 lines. The lines are insulated each with rubber tex and then put inside of a 6 inch drain pipe. yes all 4 will fit. Rubbertex thin wall pipe insullation gives you more room. the lines do not touch each other. You will need the crimping tool if you use the pex fittings. If you do not have one or want to buy one you can rent one to use for a day to do the install.

AH! I did no know this about your brand boiler. The tool I was talking about on the pex-al-pex is something I saw the plumbers do once, it removed the thin aluminum before the y could crimp it. I have a crimper and do some pex lines from time to time with my work.
Can you use one of the lines to fill the boiler?