I have a series of questions about a potential repipe.
Background; I'm an ME with over 40 years of DIY experience. I've got
a couple of older properties that are in need of repipes to replace
failing galv steel systems. I grew with copper (CTS) systems & have
experienced very good performance with them. No leaks, easy to make
minor mods, etc. Part of me is thinking CTS because of my experience
with it. But the idea of sweating all those joints in the crawlspace
does not have me excited about this job. Based on comments from a few
contractors I know, I'm think of making the jump to a PEX system. I've
read a lot about PEX on the web & I've searched the groups but
questions still remain.
Both properties are built over crawlspaces; one ranch style (~2000
ft^2), the other a 1 1/2 story.
The first project is the ranch style. I've got both design &
Installation / materials questions first:
Crimpers & expanders are mentioned when talking about PEX fittings.
Which are used/recommended for fresh water systems? The hand expander
costs about 2x more than the comparable crimper. The hand expander
looks slower & potentially more tiring than a crimper but might work
better in close quarters. The battery expander looks pretty cool but
rather spendy for only a few jobs. Bras or EPS fittings? My "old
school" self leans towards brass.
I guess the next questions are more design "style" questions.
Other than the failing steel pipe, the ranch also has the "shower far
from the water heater issue" (~80ft) which is amplified by the feeble
flow thru the ancient steel pipe. So I'm thinking about a timer run hot
water loop with repipe to give some really nice performance. Since I'm
repiping anyway it will be a little more work to add the hot water
But the hot water loop seems inconsistent with the manifold
installation concept unless the hot water mainfold is near the major
bathrooms? (two co-located, back to back bathrooms, ~80 ft from WH).
Hot water "home runs" from the water heater area (in laundry room, near
kitchen) to every bathroom hot water need (two sinks, two showers, one
tub) seems wasteful of PEX tube & don't seem to solve the waiting for
hot water issue?
Relocating the WH is not an option & I'm not up for doing the tankless
thing at the bathroom point of use.
I was thinking that a remote located HW manifold much closer to the
bathrooms might be the solution. I could tear open a hallway wall next
to the bathroom & install the hot water manifold there. Or give up
another 3ft or so & put it in an existing closet across the hall. The
remote manifold could be served by a timer controlled hot water loop
thus elimininating about 75% (60' out of 80') of the hot water wait
Now more questions;
IF the remote hot water manifold is a good idea, how large a tube to
supply it? 1/2? 3/4? Max hot water demand from bathrooms would be two
showers at a time & MAYBE a sink. About 4gpm max hot water demand? With
an 80 ft run of 1/2" PEx that would be about 16psi pressure drop.
Sounds like 1/2" could do it? Or just bite the bullet & go to 3/4" to
serve the mainfold & have a ???" run on hot water retun loop?
In SoCal does /should a PEX hot water loop be insulated? Overkill? Not
Thanks for taking a look at this. Hopefully replies will get me off
TDC & get this project going. :)