Types of lines, pros and cons

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Pat32rf

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Sep 23, 2012
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I am laying out a simple heat source for a small house and need to decide on the type of pipe to use. A lot of locals just buy regular PEX from the hardware store and run it, expecting that their unit WILL rust out after 7-10 years of running well water in it....
If I use regular Pex, will water treatment control the oxygen or do I need PEX-AL-PEX? My pipe loop will have some copper pipe for the DHW sidearm heat exchange and possibly some brass or aluminium in the main heat exchanger for the forced air system, plus the iron pipe and tank at the P&M boiler....
Next summer I will be running PEX over to my house and foaming it as I have a supply of used styrofoam to build a "long box" about 150' long. Will it need to be PEX with an oxygen barrier or will the foam and dirt suffice?
This fall I will just be using the boiler to add some heat to a small rental house.
In both cases the thought is basically to heat the basement and let the heat rise, refining the systems as we go. We cut our own wood and it has been getting burnt in main floor wood stoves with fans blowing the heat thru the houses. In each case we have had to add a bit of electric on those minus 30C days...Hoping that the OWB will supply the main heat with the fireplaces just for top up and ambience....
 
Pat32rf said:
I am laying out a simple heat source for a small house and need to decide on the type of pipe to use. A lot of locals just buy regular PEX from the hardware store and run it, expecting that their unit WILL rust out after 7-10 years of running well water in it....
If I use regular Pex, will water treatment control the oxygen or do I need PEX-AL-PEX? My pipe loop will have some copper pipe for the DHW sidearm heat exchange and possibly some brass or aluminium in the main heat exchanger for the forced air system, plus the iron pipe and tank at the P&M boiler....
Next summer I will be running PEX over to my house and foaming it as I have a supply of used styrofoam to build a "long box" about 150' long. Will it need to be PEX with an oxygen barrier or will the foam and dirt suffice?
This fall I will just be using the boiler to add some heat to a small rental house.
In both cases the thought is basically to heat the basement and let the heat rise, refining the systems as we go. We cut our own wood and it has been getting burnt in main floor wood stoves with fans blowing the heat thru the houses. In each case we have had to add a bit of electric on those minus 30C days...Hoping that the OWB will supply the main heat with the fireplaces just for top up and ambience....
Click to expand...
I also built a styrofoam box about 125' long...not happy with the results...I'd next foam in place as explained elsewhere here, or use the insulated dual pex pipe with the consensus leaning to the spray foamed type over the wrapped style. Regards, Scotty
 
Not a player here, but how didn't the styrofoam box work out? Was it XPS board, or something else, and how was it put in? Just interested. Thanks.
 
velvetfoot said:
Not a player here, but how didn't the styrofoam box work out? Was it XPS board, or something else, and how was it put in? Just interested. Thanks.
Click to expand...
I recall I used 2" bead board, top, bottom, sides...I don't believe I sleeved each 3/4" pex or not (I'll know when I did it up this Spring). In 125' of 3/4" pex I was losing 15 or more degrees.
Our replacement will be the urethane spray foam insulated pipe, such as Urecon...in a 1-1/4" size
Regards, Scotty
 
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I am planning on using the beadboard as a casement to hold the PEX as I foam everything together. I was quoted about $.80/foot for regular PEX, versus $15/ft for the good foam stuff....
The run will be under my wifes flower garden beside the driveway.. Might even stick a third run on a separate valve so we can heat things up early in the spring LOL This run would be in parallel with the main return line but not have much insulation....
 
Even if you were not burying the tubing, is it worth it to not use barrier tubing? Corrosion will happen if there is any ferrous material in your loop. Not using the proper tubing will likely void your boiler warranty.
Use oxygen barrier Pex, copper or Pex-Al-Pex. It is cheap insurance.
You cannot rely on foam or dirt to be a barrier.
The appropriate insulation is not EPS or XPS. Polyiso foam is the only foam insulation that is going to tolerate temperatures over 160F. Polystyrenes start to melt above 160F.
 
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Part of my problem is availability. The local hardware sells "what everyone uses" (non barrier) and our neighborhood "everyone" who will be helping me, just uses automotive antifreeze in his. Didn't know if it was worth the trouble to hold out for the good stuff. Sounds like it is....Didn't expect the closed cell to melt at that low temperature...
For the distance involved and the cost of fittings it looks like I can use copper pipe on my indoor runs..
 
Where are you located? Sounds like "everyone" is a boiler/heating system grenade technician.....

Some type of oxygen barrier PEX is required, and using chemicals to combat non-barrier pipe is much more expensive in the long and short run. FWIW you can get most all you will need from pexsupply.com and have it shipped to your door. I have used them on occasion with good success, as most copper fittings are cheaper on there then I can get them at my supplier locally.

TS
 
BoilerMan said:
Where are you located? Sounds like "everyone" is a boiler/heating system grenade technician.....

Some type of oxygen barrier PEX is required, and using chemicals to combat non-barrier pipe is much more expensive in the long and short run.......

TS
Click to expand...

I'm used pexsupply too, but when found more affordable PEX tubing source canarsee.com I forget all other online supplies, I love them for free shipping for all pex supplies.
 
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Yeah ^ I do not actually buy any PEX from pexsupply.com just fittings and such. I will only use PEX-a such as Uponor, Mr.PEX etc. All the other stuff is too much like trying to unfold a steel coil. Once you've used the good stuff, ya cant go back.

TS
 
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