[Greenbuilding] [BULK] Sprinklers-and PEX

[Speireag Alden]

Sgrìobh Sacie Lambertson:

>Why not use PEX instead of PVC for a sprinkler system, as well as for
>all house plumbing needs?

     Why not, indeed?

>I learned to my distress PEX can not be used in solar water systems
>because it can't take the heat, distressed because I embedded it in
>my walls and to the roof in preparation for just this.  But
>otherwise, what is bad about it?   Sacie

     PEX-AL-PEX, which has an aluminum layer, is much more heat resistant.

     That said, you can design a solar system such that it will not 
melt regular PEX.  You just have to make sure that there's no 
condition where the panel is producing more heat than the fluid can 
carry away while staying under the PEX's temperature limit.

     Potentially, to spare the embedded pipe, you could put a 
sacrificial section in:  stub the PEX to a connector, and then attach 
another few feet of PEX.  If it does melt through, then you can 
replace the extra section from the joint outward toward the heat 
source without worrying about the length which is embedded.

-Speireag.

-- 
Anger, if not restrained, is frequently more hurtful to us than the 
injury that provokes it.
--Lucius Annaeus Seneca, philosopher (BCE 3-65 CE)