Print

[johnybcold]

I think spray foam in the pipe is the way to go.

[Scott7m]

When it comes to pex and plumbing I know that uponor is top notch material, I'd say hydronix knows what he's talking about

[boilerman]

I have now had Central Boilers Thermopex in the ground for 7 years. Buried with only 6 inches of dirt over the top, where the ground freezes 4-5 feet deep in Central MN. Zero heat loss and Zero melting over the line. 90 feet from boiler to my house. You can't beat a urethane delivery line. Yeah, it costs a little more and is kind of a bear to handle, but once you have it in the trench, you won't have to deal with it again. Well worth the cost IMO.

[Hydronix]

Do a search on foam types and ratings. You will find CFC and non-CFC and many other types of materials. The good stuff is not used much anymore because of the chemical dangers some claim. There is very good spray foam out there, just make sure you know what your getting. Most foams loose there R value ( called thermal drift) usually a few % but up to 50% or break down over time when the important gases leach out. It all depends on the installers mix and what type of chemicals he is using. They are finding that 2" rigid foam board they used to put on the exterior of foundations or basement walls is breaking down and becoming water logged in some cases where builder bob tried to save a buck. In order for you to verify what your paying for, you can request a MSDS sheet.  Its called Thermal Drift and there is some info here, I'm trying to find a chart that had the many different types of spray foam, closed cell,open etc.

http://www.energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11700
http://www.energysavers.gov/your_home/insulation_airsealing/index.cfm/mytopic=11510

In the end you get what you pay for, and it is so true for these Header supply lines. In big industrial applications, check out Dritherm. If you can find a feasable supplier, you might be able to salvage what you have already
http://dritherm.com/ 

[tbone]

Hydronix,
The pipe I'm considering has a continuous 6mil polypropylene shell with a foam center.  What do you think?  I'm guessing if water can't get in I will be fine.  I was going to add another layer of sealed 6mil poly wrap...any thoughts? 

[Hydronix]

Hydronix,
The pipe I'm considering has a continuous 6mil polypropylene shell with a foam center.  What do you think?  I'm guessing if water can't get in I will be fine.  I was going to add another layer of sealed 6mil poly wrap...any thoughts?

What I think,,,,,, would be nothing more than a guess until we see some pix and manufacturer specs. Everyone likes pictures

[tbone]

Flexsul-Seal Specs

Exterior skin consists of 50 mil Polyethylene Corrugated Tubing

Exterior skin complies with ASTM F405-97 for H.D. tubing

All Pex Tubing Meets Applicable Standards.

Color Coded Pex Tube Available

¾" & 1" PEX-AL-PEX Available

¾" - 1" - 1 ¼" Pex Tube Available

Thermal Insulation Properties

Operating Range:

-297 degree F to 220 degree F

>90 % Closed Cell

.02 % Water Absorption by volume

.10 Water Vapor Permeability

Passes Flame Spread of 25 as tested by ASTM E 84

Meets requirements of ASTM C 411 for Hot Surface performance of High Temperature Thermal Insulation

R-Value = 6 per inch

Non-Porous, Non Fibrous Insulation resists mold growth

3 lb/ft — 6 lb/ft Density

[tbone]

Here's a pic of the pipe.

[tbone]

I plan on putting this in 6 mil poly tubing to give it some extra protection then surround the pipe with sand then soil.  Is this a good idea? Or do you guys just back fill with soil?

[Hydronix]

If all the data is accurate according to their website, then yes this appears to be a very good pipe. I don't know if I would ever choose the 4 pipe version tho.   The important data is in the chart that shows gpm/water temp/temp differential/feet.  That is the important spec info when comparing different brands. I have seen one test where they shoved 25gpm thru at over 30' per second, and of course the temp loss was little. As soon as you slowed it down to 4gpm the loss went up 14 degrees over the same 100' of pipe. Then there was a test where they didn't put 170-180 degree water thru and it was under summertime ambient temps. They had 5gpm or less flow but not boiler like temp conditions.  A thermal imager inspection would see whats going on, but you almost never see those images.