|
|
04-12-2018, 00:18
|
#1
|
Registered User
Join Date: Feb 2017
Location: Waukegan, IL
Boat: Columbia 10.7
Posts: 670
|
1/2" or 3/4" PEX?
I patched my water tanks and replaced a bunch of supply hoses last spring on the Columbia 10.7 I bought last December. I chose to base my system on 1/2" hoses.
I have a sink in the galley, a sink and a shower in the head. The boat originally had a hot water heater but it was removed.
My plan is to eventually replace the hot water heater, but for the moment I will live with cold water only.
The current hoses are Ok but air is getting into the system somewhere and I'm thinking I'd like to switch to PEX.
So, the question is: What is the preferred size for the system I'm envisioning, with hot and cold water, and three outlets?
1/2" or 3/4" tubing?
And, what size pump?
|
|
|
04-12-2018, 05:39
|
#2
|
Registered User
Join Date: May 2017
Location: Katy, TX
Posts: 400
|
Re: 1/2" or 3/4" PEX?
It depends on whether you want volume or pressure. The 3/4" pipe will provide more volume at the same PSI but less pressure. "Good" pressure in houses is generally around 45-55 psi. 12v pumps for 50 psi are easy to find. You can get higher psi pumps, but on a cruising boat fresh water is often a resource you don't want to waste. I would go with 1/2" pipe and an adjustable psi pump up to 100 psi. Then you can control the pressure based on how much water saving you need. YMMV.
|
|
|
04-12-2018, 05:40
|
#3
|
Registered User
Join Date: May 2014
Location: Whitby, Canada
Boat: Morgan Out Island 41
Posts: 2,242
|
Re: 1/2" or 3/4" PEX?
1/2" PEX is the usual size to use. Fittings are everywhere...Homedepot not Westmarine!
|
|
|
04-12-2018, 05:58
|
#4
|
Registered User
Join Date: Dec 2015
Location: Fort Pierce Fl
Boat: Gulfstar 36 MS
Posts: 210
|
Re: 1/2" or 3/4" PEX?
Why do you need to heat hot water?
|
|
|
04-12-2018, 06:41
|
#5
|
Registered User
Join Date: May 2011
Location: Sea of Cortez and the U.P. of Michigan
Boat: Celestial 48
Posts: 904
|
Re: 1/2" or 3/4" PEX?
For heck sakes, even 3/8" would do. 1/2" is all you need for sure. 3/4" only if your goal is to drain tanks as fast as possible. Note that if you install HW heater, larger pipe means much longer wait for hot water at the tap or shower head (and more wasted water). Forget the 3/4" PEX, unless large yacht with long runs.
|
|
|
04-12-2018, 06:46
|
#6
|
Registered User
Join Date: May 2011
Location: Sea of Cortez and the U.P. of Michigan
Boat: Celestial 48
Posts: 904
|
Re: 1/2" or 3/4" PEX?
Might add, if your tank connection is 3/4" might make sense to run 3/4" to the pressure pump suction. But that's about it.
|
|
|
04-12-2018, 06:47
|
#7
|
Registered User
Join Date: Aug 2013
Posts: 44
|
Re: 1/2" or 3/4" PEX?
If you are going to be showering on board, I’d recommend 3/4".
|
|
|
04-12-2018, 07:09
|
#8
|
Registered User
Join Date: Jun 2010
Location: Easton, MD
Boat: 15' Catboat, Bristol 35.5
Posts: 3,510
|
Re: 1/2" or 3/4" PEX?
3/8" or 1/2".
|
|
|
04-12-2018, 07:17
|
#9
|
Registered User
Join Date: Aug 2018
Location: Hudson Valley, NY
Posts: 365
|
Re: 1/2" or 3/4" PEX?
Typically you want a 3/4" main with 1/2" branches to the fixtures. This will help keep the flow and pressure from dropping to much when/if multiple fixtures are used at the same time.
But on a boat with only 3 fixtures, a simple system with 1/2" throughout would be fine.
|
|
|
04-12-2018, 07:41
|
#10
|
Registered User
Join Date: Nov 2013
Location: Nice, France
Boat: Hunter Marine 38
Posts: 1,342
|
Re: 1/2" or 3/4" PEX?
On my 2005 Hunter 38 with 2 showers, kitchen and bathroom sink the piping is factory installed 15mm PEX. Blue for cold & red for hot water. Pex can be bend, but it put a lot of strain on the fittings, better use a 90° fitting, less leak prone. Ask me how I know
|
|
|
04-12-2018, 08:51
|
#11
|
Registered User
Join Date: Mar 2015
Location: Boston's North Shore
Boat: Pearson 10M
Posts: 839
|
Re: 1/2" or 3/4" PEX?
1/2" will be fine, make sure you use full flow fittings.
|
|
|
04-12-2018, 08:55
|
#12
|
Registered User
Join Date: Aug 2017
Location: Wisconsin, USA
Posts: 289
|
Re: 1/2" or 3/4" PEX?
1/2" would be much easier to work with, I would think that with the small number of "taps", 1/2" would more than suffice. Keep it simple.
|
|
|
04-12-2018, 08:58
|
#13
|
Registered User
Join Date: Feb 2017
Location: Waukegan, IL
Boat: Columbia 10.7
Posts: 670
|
Re: 1/2" or 3/4" PEX?
Thanks for the input. Looks like 1/2" is the winner. Whenever possible, I try to avoid 90 degree fittings. I prefer Ys or 45s.
|
|
|
04-12-2018, 09:07
|
#14
|
Registered User
Join Date: Aug 2006
Location: Skagit City, WA
Posts: 25,453
|
Re: 1/2" or 3/4" PEX?
1/2", more velocity.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard
|
|
|
04-12-2018, 09:16
|
#15
|
Registered User
Join Date: Feb 2017
Location: Waukegan, IL
Boat: Columbia 10.7
Posts: 670
|
Re: 1/2" or 3/4" PEX?
Quote:
Originally Posted by Outlaw7
Why do you need to heat hot water?
|
20,000 comedians are out of work and you are trying to be funny...
Ha, ha
|
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|