I’m getting ready to install AquaPEX tubing in my home. I had planned to use a compression-style Manabloc with all homeruns, using 3/8″ PEX (to minimize hot water wait times and the number of connections) for everything but my bathtub and hose bibs.
I called Uponor today and spoke to one of their technicians about their expander tool and fittings. During our conversation, this Uponor tech told me that they don’t recommend homerun systems, and that, depending on the length of the run, 3/8″ PEX may well not deliver enough water for some fixtures.
In fact, he told me that according to their figures, you lose 3 psi of water pressure per foot for 3/8″ PEX. So it would seem that any runs much over 20′ would be impractical.
So this made me go back and look at what I based my 3/8″ plans on. A Breaktime member was good enough to send me a Vanguard/Manabloc design worksheet. That worksheet recommends 3/8″ PEX for everything but bathtubs and hose bibs, and doesn’t mention length of run at all.
This is a huge issue that I have to get right. Can any of you tell me from experience if my plans to use 3/8″ are flawed?