Replies

1. 
   darrel | Jan 23, 2010 04:11pm | #1

   I'm in the same boat
   I'm in the same boat researching this stuff.

   A bit frustrated that so many of the manufacturers still only deal with 'licensed installers' and refuse to offer much direct support to consumers directly.

   Admittedly, my research has mainly been at pexsupply.com. Thus far, that seems like a pretty good site.

   For heating (which I assume is what you want with the O2 barrier) it seems that the main issue is the type of pex moreso than who's it is. From my understanding PEX-a is the most flexible in terms of expansion (in case of freezing) and bending.

   I'm looking at the 3/4 Wirsbo HePex product to replace copper that got destroyed when it all froze up this winter.

   One question I haven't found an answer to is what benefits, other than it holding it's form, does PEX-AL-PEX provide?

1. 
   Billy | Jan 24, 2010 04:06pm | #2

   Pex-al-pex provides the best oxygen barrier for use in closed systems.

   Billy

1. 
   Virginbuild | Jan 24, 2010 07:23pm | #3

   The Engel method of cross linking is considered the superior method of manufacturing PEX. It would be great for a research lab to prove out the product quality and durability from the different manufactureing processes.

1. 
   Billy | Jan 25, 2010 01:27am | #4

   There are at least 4 kinds of PEX. There is Pex-A, PEX-B, and PEX-C, described below:

   http://www.greenbuildingtalk.com/Forums/tabid/53/forumid/12/postid/65081/view/topic/Default.aspx

   http://www.wirsbo.com/en/Misc/Applications/PEX-Plumbing.aspx

   http://www.lubrizol.com/FBC2col.aspx?id=36546&ekfxmen_noscript=1&ekfxmensel=eeb11f83c_222_642

   There is also PEX-AL-PEX which has a layer of aluminum as an oxygen barrir in the PEX tubing. PEX-AL-PEX is best used in radiant heating systems because they are usually closed systems (as opposed to open drinking water systems) and you don't want oxygen getting inside the tubing and corroding the pumps, valves, boiler, etc. In addition, the PEX-AL-PEX has 1/9 the thermal expansion of regular PEX, so it reduces the possibility of noise in radiant heating systems (noise can come from the pipe sliding in the aluminum transfer plates or inside walls and floors).

   http://www.builditsolar.com/Experimental/PEXCollector/PEXALPEX.htm

   http://www.mrpexsystems.com/aluminumpex.asp

   Billy

1. 
   darrel | Jan 25, 2010 07:25pm | #5

   So...given the choice between PEX-AL-PEX where the pex is PEX-B and Oxygen Barrier PEX-A, which would you prefer?