Dual pex- wrapped, spray foamed, Standard, Metric: Opinions

[Scotty2]

I'm in the process of looking into the various insulated 'dual pex' options. Any insight and opinions are appreciated. (This will be running from a GARN 2000 125' to a poorly insulated Quonset style warehouse)

We have 7 500' runs of 1/2" currently fed by a single 3/4" feed line...poorly insulated to boot, (Thankyou F... S....), I'm looking into 1-1/4" or 32mm as the replacement..(It's been suggested I look at dual runs of dual 1" or go up to 1-1/2" due to the long runs of 1/2" in the slab..still thinking on this)

I've been checking pricing on the spray foam insulated (polyurethane?) with a slight preference to 32mm (1.28" ID compared to 1.054" ID for 1-1/4)

The 4 I've narrowed it down to are:

• LogStor/Urecon-Dual Pex (smooth exterior) available in 1-1/4 or 32mm (which is 1.28" ID)...around $14plf
• Rehau/Insulpex (not the wrap, the spray foam style)...supposedly available either profile online for $10-$11plf (factory rep says no dual 32mm in US)
• Rhinoflex/Rovanco 1-1/4 is 1.054ID (that's why I like the 32mm)...running around $11.50
• Thermopex, (through Central Boiler dist?)...$14.50 (often a double shipping charge here...factory to them, them to you).

All are plus shipping which can add up to several dollars plf extra.

Several other brands looked equally as good for quality, however they often will only sell Wholesale to a Plumber, while others were quoting up to $38plf...
Regards, Scotty

 

[rowerwet]

Dual runs of thermopex have a higher flow rate and lower heat loss rating (1°/100') but price will be up there.
Many have good luck foaming pex in place, it is much more work, but this may be how you save money.
Either way, don't cheap out on the lines, the cost in pex is one time, wasted heat is forever, and will cost even more to redo.

 

[Scotty2]

One advantage to dual runs is I could leave the existing 3/4" feed line in place and have it tap into the back set of 3 500' 1/2" runs...where I run just the heat enough to keep above freezing. Then install a 1" insulated dual pex to run the front 4 sets of 500' 1/2" lines where most of the work is done.
I researched the foam in place...a bit. Local (within 50 miles) 'foamers' give me a blank look when I explain (and show the pics) of what I'm thinking about. Moving into Winter now I'm thinking it will be easiest to use a walk behind trencher and lay in the insulated pipe.
Regards, Scotty

 

[rowerwet]

My central boiler dealer didn't charge shipping because I bought what he had in stock, then brought it home in my own truck. Being able to just drop thermopex into a shallow trench was nice.

 

[Buzz Saw]

I'm in the process of looking into the various insulated 'dual pex' options. Any insight and opinions are appreciated. (This will be running from a GARN 2000 125' to a poorly insulated Quonset style warehouse)

We have 7 500' runs of 1/2" currently fed by a single 3/4" feed line...poorly insulated to boot, (Thankyou F... S....), I'm looking into 1-1/4" or 32mm as the replacement..(It's been suggested I look at dual runs of dual 1" or go up to 1-1/2" due to the long runs of 1/2" in the slab..still thinking on this)

I've been checking pricing on the spray foam insulated (polyurethane?) with a slight preference to 32mm (1.28" ID compared to 1.054" ID for 1-1/4)

The 4 I've narrowed it down to are:

• LogStor/Urecon-Dual Pex (smooth exterior) available in 1-1/4 or 32mm (which is 1.28" ID)...around $14plf
• Rehau/Insulpex (not the wrap, the spray foam style)...supposedly available either profile online for $10-$11plf (factory rep says no dual 32mm in US)
• Rhinoflex/Rovanco 1-1/4 is 1.054ID (that's why I like the 32mm)...running around $11.50

• 
  
  Any idea on how much that .22" more impacts flow?

 

[Heat1285]

also check out the XT product from Z-Suppy....double walled, very durable.

 

[Scotty2]

I've heard that 1-1/4" thermopex is a true 1-1/4" ID. Anyone out there got a piece they can measure?
Regards, Scotty