[Greenbuilding] 3/8" domestic hot water supply line?

[Drew A. Gillett, P.E.]

standard ( i.e. uninformed ) practice seems to be to go to larger and larger 
supplies ( the jacuzzi, you know) and smaller and smaller feed lines at the 
fixtures (with small valves.)  this is of course nuts.

the original nahb study on tankless vs tank  was actually a study on home 
run versus tree distribution and plastic versus copper and underslab versus 
in attic.   a review of that reference ( months ago in archive) would bring 
you up to speed.

smaller, better insulated is the way to go until you exceed pressure loss 
for fixture requirements.  if you don't pay directly to pressurize ( town 
water) then small is good.  if you do pay (well water, or off grid) then not 
so good.

hope this helps.
----- Original Message ----- 
From: "Reuben Deumling" <9watts at gmail.com>
To: "Greenbuilder list" <GREENBUILDING at listserv.repp.org>
Sent: Thursday, June 21, 2007 3:43 PM
Subject: [Greenbuilding] 3/8" domestic hot water supply line?


> Can anyone speak to the desirability of a <1/2" hot water line? I've heard
> tell that this is a good idea and am very sympathetic to the physics of 
> what
> I think the argument is. Are there reasons to be wary of this? Water
> pressure concerns at 2gpm? Are 3/8" PEX fittings readily available? 
> Although
> code is not specifically an issue for this next project, do our plumbing
> codes speak to this? And yes, keeping the runs from the water heater to 
> the
> end uses as short as possible is at the top of my list.
>
> Thanks.
>
> Reuben Deumling
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