Pex Piping for Residential Plumbing
dfvellone
| Posted in General Questions on
Moving on to plumbing in my house project, I plan on home-run approach and have a 230′ and 185′ roll of 1/2″ alumicore pex left over from a radiant installation.
Will this not have the flexiblity required for turns, and are there other issues (potability, use with fittings) that would quickly negate the financial savings?
Thank you, Daniel
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Replies
You'd need to check if the material you has is listed for use with potable water, which is likely to be printed on the jacket with the NSF mark.
Aluminum is much more subject to corrosion depending on your specific water chemistry. I'd prefer "regular" PEX myself, since cross linked polyethylene is very stable, an inert material, so it's not going to react to whatever might be in your water. I haven't used alumapex for anything myself, so I can't really offer much else.
Bill
There is a Pex inner core. The aluminium core is sandwiched between two Pex layers so water never comes in contact with the aluminium.
Pex-Al-Pex is probably the best pipe system in my opinion but it's more expensive than Pex and uncommon in NA. More popular in Europe. Much more flexible than Pex.
Does not answer your question, but consider a recirc system instead of a home run system.
My shower is 6' from my water heater in plan, in a home run configuration, but it still takes over 10 seconds for hot water to get to the shower and I get aggravated at the wasted water every morning. My contractor dismissed recirc systems every time I brought it up mostly because I think he did not listen to the options and assumed the pump would run 24/7. There are all sorts of strategies for a great recirc system that do NOT waste energy You can wire the recirc pump to the light switches and set the pump to momentarily run for x minutes every time a bath/shower light, kitchen light or laundry light is turned on. You can put a motion sensor in each of those spaces to trigger the recirc pump to run for x minutes upon trigger of the motion sensor, you can put a regular switch in to trigger the pump, etc. If you have an efficient hot water system, controlled recirc works well and wastes so much less water...
Pex-Al-Pex takes different fittings from regular Pex. A 300' roll of Pex is $89. It's just not worth getting the special fittings. Sell or give away your surplus on Craigslist.
Bell & Gossett "ecocirc" recirculation pumps draw very little current - about as much as an old-style incandescent bulb night light - when in use and can be outfitted with timer or temperature controls to minimize energy usage. Of course, you also want to insulate the recirculation line very well to cut down on any heat loss. A dedicated recirculation pump at the water heater beats is a nice addition if you have access / or in new construction.
I believe the previous title on this thread was "Pex-al-pex for potable/household plumbing use?"
GBA Folks: I implore you to stop re-titling threads. It makes it hard to find something you've already seen and is just confusing in general.
In this case, the original title is more descriptive of the topic.
In this case, I agree. The original post is about using a specific type of PEX, and it's a type that is far less common than the regular stuff. It doesn't make sense to make the title imply this thread is about a more general use of the regular PEX material in residential builds.
Bill