Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 08-06-2021, 11:02   #1
Registered User

Join Date: Aug 2009
Location: Norfolk, Virginia
Boat: 1984 Passport 42 pilothouse cutter
Posts: 374
PEX for raw water - Airconditioner

I did a search but i couldn't find much on PEX with saltwater.

I am installing an air conditioner, and looking at the raw water system now. was thinking of using reinforced hose from the strainer to the pump but thinking of using PEX from the pump through the air conditioners to the vented loop. from the vented loop to the discharge use reinforced hose again. In theory this makes for a low friction system, however I have a spool of yellow 5/8" PEX (1/2" ID) that would work well. pressure, vibration, and freeze proof of the PEX seem good for this application.

Would PEX work good in this situation, is there something I am not thinking of or considering with this?

Thanks

Robert
alaskanviking is offline   Reply With Quote
Old 08-06-2021, 11:06   #2
Registered User
 
Sailmonkey's Avatar

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 9,368
Re: PEX for raw water - Airconditioner

1. Why do you have a vented look in your AC system?

2. What fittings do you propose to use with the pex? Iíve thought of using pex like this as well but couldnít locate suitable fittings for use with seawater.

3. Most air conditioners require a hose that is 5/8Ē ID, not 1/2Ē.
Sailmonkey is offline   Reply With Quote
Old 08-06-2021, 11:22   #3
Registered User

Join Date: Aug 2009
Location: Norfolk, Virginia
Boat: 1984 Passport 42 pilothouse cutter
Posts: 374
Re: PEX for raw water - Airconditioner

Quote:
Originally Posted by Sailmonkey View Post
1. Why do you have a vented look in your AC system?

2. What fittings do you propose to use with the pex? Iíve thought of using pex like this as well but couldnít locate suitable fittings for use with seawater.

3. Most air conditioners require a hose that is 5/8Ē ID, not 1/2Ē.
Thanks for the response. I am putting in a vented loop, as that is the standard for running any kind of raw water system where its possible to siphon. the discharge is close enough to the waterline. i don't have fuel in the tanks and a likely genset install will drop that lower.

now that I think of it I am not running the unit underway, and would have the seacock closed. do i need a vented lop? does anyone else put one in? generally I tend towards overbuilding and safety

i had a hell of a time finding fittings for 5/8" pex, its very limited. I did find that regular hose barbs work well without issue. was going to use 2 of the copper compression rings per connection. I did my freshwater system this way and it works well.

I'm running over to pick up the unit shortly, just got delivered, so I haven't had a chance to see what's in the box. I thought the manual said 1/2" but i could be wrong. 5/8" ID is 3/4" PEX I believe.
alaskanviking is offline   Reply With Quote
Old 08-06-2021, 11:50   #4
Registered User
 
Sailmonkey's Avatar

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 9,368
Re: PEX for raw water - Airconditioner

A vented loop is used to prevent flooding when there is an item open to the interior of the vessel. The AC system is not that, adding a vented loop to this is adding a failure point. Seacock open or closed, a vented loop isnít the right thing for use here.

Be carful of using brass hose barbs. They wonít last long. You need either plastic or bronze.

Also remember that youíll need to periodically take apart the hoses for cleaning (ac systems grow and harbor all sorts of goodies) so you donít want to use the copper crimp rings.
Sailmonkey is offline   Reply With Quote
Old 08-06-2021, 13:57   #5
Marine Service Provider

Join Date: Jun 2019
Location: Southern California
Posts: 317
Images: 2
Re: PEX for raw water - Airconditioner

Do not vent the ac raw water!!!
Use 5/8"id hose designed for raw water/exhaust/ heater.
Trident makes a good quality hose that we use extensively.
There are many other options that are available as well.
Double opposed hose clamps on every fitting.
Silicone bronze or sch 80 cpvc only fittings, or cu-ni if you can find them.
Make sure the condensate pan drains efficiency!
Good luck!
Not sure how you think it will siphon, it will drain to the waterline, unless of course you plumbed it with an airlock built in.
Coolerking is offline   Reply With Quote
Old 09-06-2021, 10:39   #6
Registered User

Join Date: Nov 2017
Location: Portland, Oregon USA
Boat: Island Packet, Packet Cat 35
Posts: 822
Re: PEX for raw water - Airconditioner

I used pex with nylon barb connectors/reducers. It worked fine for 2 years. I removed the reverse cycle heat pump for other reasons.
Cpt Mark is online now   Reply With Quote
Old 09-06-2021, 11:49   #7
Registered User

Join Date: Aug 2009
Location: Norfolk, Virginia
Boat: 1984 Passport 42 pilothouse cutter
Posts: 374
Re: PEX for raw water - Airconditioner

Copy-all on the no vented loop.
I got my unit yesterday afternoon. definitely 5/8" ID.
Is there any advantages to using the PEX vice raw water/exhaust/ heater hose?

I was thinking the PEX is slicker so there is less friction for a smidgeon of more efficiency, and in theory harder for algae and critters to grow inside. Cpt Mark have you noticed a lot of growth in your system. curious at this point. I don't have 3/4" PEX (5/8" ID) or raw water/exhaust/ heater hose yet as I am currently on plan D or E of mounting and ductwork.

Click image for larger version

Name:	PXL_20210608_201312624.jpg
Views:	27
Size:	266.7 KB
ID:	240028

Click image for larger version

Name:	PXL_20210608_201336265.jpg
Views:	22
Size:	235.4 KB
ID:	240029

Click image for larger version

Name:	PXL_20210608_201230921.jpg
Views:	24
Size:	122.3 KB
ID:	240030

Click image for larger version

Name:	PXL_20210608_201253941.jpg
Views:	26
Size:	129.5 KB
ID:	240031
alaskanviking is offline   Reply With Quote
Old 09-06-2021, 12:32   #8
Registered User
 
Sailmonkey's Avatar

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 9,368
PEX for raw water - Airconditioner

This is my Go to hose for ac water

https://citimarinestore.com/en/domet...t-450-psi.html

According to cpt marks profile heís in Oregon. The further south you are and the warmer the water the more goo grows in the lines. Iíve just replaced a raw water hose on a chiller condenser that was choked closed with barnacles.
Sailmonkey is offline   Reply With Quote
Old 09-06-2021, 13:21   #9
Registered User

Join Date: Nov 2017
Location: Portland, Oregon USA
Boat: Island Packet, Packet Cat 35
Posts: 822
Re: PEX for raw water - Airconditioner

Yes I am in Portland OR on the Columbia river so mostly just fresh water. Certain times of the year we get brackish water but no barnacles
Cpt Mark is online now   Reply With Quote
Reply

Tags
raw water, water

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale: Cruisair 10k btu airconditioner resoluute General Classifieds (no boats) 2 01-05-2020 10:31
PEX for raw water Dartanyon Plumbing Systems and Fixtures 4 13-06-2018 09:06
Best reverse cycle heat / airconditioner a64pilot Construction, Maintenance & Refit 51 22-10-2016 06:58
Airconditioner Venturi a64pilot Construction, Maintenance & Refit 12 18-08-2015 17:57

Advertise Here


All times are GMT -7. The time now is 10:26.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.