Cruisers Forum
 


Join CruisersForum Today

View Poll Results: How often do you flush the seawater side of your air conditioner
Yearly 7 28.00%
every 1-2 years 6 24.00%
very 3-4 years 1 4.00%
every 5-6 years 0 0%
less often than every 6 years 0 0%
more than once a year 2 8.00%
never and my system is x years old (post the years) 7 28.00%
what's an air conditioner on a boat 1 4.00%
I just go out and bring in a new ice berg 0 0%
I'm here to cause trouble 1 4.00%
Multiple Choice Poll. Voters: 25. You may not vote on this poll

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 28-06-2019, 07:06   #1
Are you serious?
 
sailorboy1's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: On the boat somewhere
Boat: Hunter 410
Posts: 15,163
Air Condtioner Flushing Frequency

I've never flushed the seawater side of my AC in the 9 years I've had the boat. Yet I have read lots of posts about people doing it every year etc. Now I do put a couple of AC Pan tablets in the strainer when I check/clean it. But I really doubt that they can dissolve fast enough and last long enough to acturally get to the min kill dose level for bio in the system. Meanwhile there is lots of flow through my system (because I do go out and check) and the AC is cooling fine (I can tell when the strainer is clogged up but before the point that the system shuts down).

I've run the system in some high scale areas that people like to use as excuse for my crappy bottom paint performance. So don't suggest I'm in "good" water.

So how often really are people doing this flush thing?

I'll put a poll on.
__________________

__________________
jobless, houseless, clueless, living on a boat and cruising around somewhere
sailorboy1 is online now   Reply With Quote
Old 28-06-2019, 07:22   #2
Writing Full-Time Since 2014
 
thinwater's Avatar

Join Date: Nov 2008
Location: Deale, MD
Boat: PDQ Altair, 32/34
Posts: 6,392
Re: Air Condtioner Flushing Frequency

Never. If the seacocks are closed periodically, the Cu ion concentration inside a sealed pipe is high enough to kill everything (test it under the dock).


Scaling takes considerable heat and should only be a problem if there is a flow restriction.
__________________

__________________
Gear Testing--Engineering--Sailing
http://sail-delmarva.blogspot.com/
thinwater is offline   Reply With Quote
Old 28-06-2019, 07:26   #3
Senior Cruiser
 
Sailmonkey's Avatar

Cruisers Forum Supporter

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 7,226
Re: Air Condtioner Flushing Frequency

Weíve had the AC in the boat now for 7 years. Iíve never flushed it, but have a theory about that.

What Iíve observed is that flushing is required when the AC is left on continuously, either as a dehumidifier or to keep the boat cool for whatever reason. This continuous operation makes a perfect environment for algae and filter feeders to setup shop and thrive with a constant food source pumped through.

Weíve not been living on the boat, and use a dehumidifier when not aboard. This means that our AC runs for literally a handful of hours a month. The rest of the time the plumbing is devoid of oxygen or food for the critters. I have seen a really funky discharge after turning on the unit for the first time in weeks though, suggesting that something has died in the plumbing and is being pumped out.

If I remember to get to the poll from another device Iíll fill it in.
Sailmonkey is offline   Reply With Quote
Old 28-06-2019, 07:32   #4
Registered User
 
wingless's Avatar

Join Date: Aug 2013
Boat: 2000 Searay 380 Sundancer
Posts: 736
Re: Air Condtioner Flushing Frequency

My boat has two air conditioners sharing a single seacock, strainer and pump.

Every couple of months during extended usage the water stream exiting the hull is not as perfect as desired, w/ some dribbling from the mushroom through hull.

My solution is to use a small garden hose fixed jet nozzle attached to my Salt Away mixer. I use boat wash soap in that mixer, shut off the seacock, so water forced into one exits the other.

The jet nozzle is jammed into the mushroom through hull and soapy water cleans the raw water circuit. I alternate between the two through hulls, forcing soapy water in both directions through the raw water circuit.

This method has been used w/ success for 17 years.
__________________
2000 SeaRay 380 Sundancer Mercruiser
454 MAG MPI Horizon 380hp / Westerbeke 7.0KW BCGB
many cool mods
wingless is offline   Reply With Quote
Old 28-06-2019, 07:44   #5
Registered User
 
MV Wanderlust's Avatar

Join Date: May 2016
Location: Palmetto, FL
Boat: "Wanderlust" -- 1999 Jefferson Rivanna 52'
Posts: 742
Images: 27
Re: Air Condtioner Flushing Frequency

In central West coast Florida, a/c runs pretty much constantly most of the year. I make it a habit to flush the a/c at the start and end of summer. It's amazing the amount of crud that comes out each time. In the summer months, the strainer needs to be cleaned every week, too.

John
MV Wanderlust is offline   Reply With Quote
Old 28-06-2019, 09:22   #6
Are you serious?
 
sailorboy1's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: On the boat somewhere
Boat: Hunter 410
Posts: 15,163
Re: Air Condtioner Flushing Frequency

Quote:
Originally Posted by thinwater View Post
Never. If the seacocks are closed periodically, the Cu ion concentration inside a sealed pipe is high enough to kill everything (test it under the dock).


Scaling takes considerable heat and should only be a problem if there is a flow restriction.
that's true, in my 15 years of treating cooling tower and chiller systems the ones with a lot of copper piping never had as much of a biological issue.

The LSI is about 1 and that is scale forming no matter what. But velocity through the tubes probably blows most out.
__________________
jobless, houseless, clueless, living on a boat and cruising around somewhere
sailorboy1 is online now   Reply With Quote
Old 28-06-2019, 09:42   #7
Moderator Emeritus
 
Hudson Force's Avatar

Cruisers Forum Supporter

Join Date: Nov 2008
Location: Lived aboard & cruised for 45 years,- now on a chair in my walk-in closet.
Boat: Morgan OI 413 1973 - Aythya
Posts: 7,969
Images: 1
Re: Air Condtioner Flushing Frequency

In addition to scaling there can be a mud-like coating that accumulates in an estuarine environment. When my AC systems were running with less efficiency, I found that I could run a soft auger through the raw water coils to clean out this mud coating. The leashes that surfers use to lash their boards to their ankles are perfect for this. I cut the ends off of a surf board leash for this. I used the surfers leash for running through other fittings or hoses where I was careful not to scour or damage anything. The surfer's leash is also great for clearing the algae out of the effluent through-hulls.
__________________
Take care and joy, Aythya crew
Hudson Force is offline   Reply With Quote
Old 28-06-2019, 09:48   #8
Registered User

Join Date: Jan 2017
Location: Everywhere
Boat: 2011 FP Orana 44 M
Posts: 770
Re: Air Condtioner Flushing Frequency

Only owned the boat about a year, but we haven't run anything but seawater through ours. When we're out on the hard I open the seacocks and drain everything out. That's happened twice (once for inspection, once for some refit work).

Incidentally, I finally got everything wired up correctly and I'm now running aircon in the salon while on a mooring ball, from solar/batteries. Yay!
LoudMusic is offline   Reply With Quote
Old 28-06-2019, 10:49   #9
Registered User

Join Date: Sep 2008
Location: new orleans
Boat: hunter 27, hunter 41
Posts: 190
Re: Air Condtioner Flushing Frequency

I have connected a female hose fitting on my seawater inlet line. I close the thru hull, connect a garden hose and blast city water thru the system. As this is quite a bit more pressure than the seawater pump provides it blows everything out. My reason for doing this was the low stream from seawater pump and ac units overheating. Once I blew out the cooling lines with high pressure water large clouds of stuff exited the cooling system. I have never been envious of anyone else stream since.
dakno is offline   Reply With Quote
Old 28-06-2019, 10:50   #10
Registered User
 
MV Wanderlust's Avatar

Join Date: May 2016
Location: Palmetto, FL
Boat: "Wanderlust" -- 1999 Jefferson Rivanna 52'
Posts: 742
Images: 27
Re: Air Condtioner Flushing Frequency

Quote:
Originally Posted by dakno View Post
I have connected a female hose fitting on my seawater inlet line. I close the thru hull, connect a garden hose and blast city water thru the system. As this is quite a bit more pressure than the seawater pump provides it blows everything out. My reason for doing this was the low stream from seawater pump and ac units overheating. Once I blew out the cooling lines with high pressure water large clouds of stuff exited the cooling system. I have never been envious of anyone else stream since.
Iím actually installing a similar fitting tomorrow morning. Looking forward to trying it.
MV Wanderlust is offline   Reply With Quote
Old 28-06-2019, 10:56   #11
Registered User
 
wingless's Avatar

Join Date: Aug 2013
Boat: 2000 Searay 380 Sundancer
Posts: 736
Re: Air Condtioner Flushing Frequency

Quote:
Originally Posted by dakno View Post
I have connected a female hose fitting on my seawater inlet line.
My concern w/ doing any non-ABYC modification like this regards possible / unlikely failures.

The insurance company will do a forensic analysis of any significant loss. If they can point at this causing the loss to avoid coverage payment then this non-ABYC modification is too great a risk.
__________________
2000 SeaRay 380 Sundancer Mercruiser
454 MAG MPI Horizon 380hp / Westerbeke 7.0KW BCGB
many cool mods
wingless is offline   Reply With Quote
Old 28-06-2019, 13:41   #12
Registered User
 
PuttingDoctor's Avatar

Join Date: Jun 2014
Location: Daytona Beach, Fl
Boat: Irwin 46 CC
Posts: 333
Images: 1
Send a message via Skype™ to PuttingDoctor
Re: Air Condtioner Flushing Frequency

Quote:
Originally Posted by wingless View Post
My boat has two air conditioners sharing a single seacock, strainer and pump.

Every couple of months during extended usage the water stream exiting the hull is not as perfect as desired, w/ some dribbling from the mushroom through hull.

My solution is to use a small garden hose fixed jet nozzle attached to my Salt Away mixer. I use boat wash soap in that mixer, shut off the seacock, so water forced into one exits the other.

The jet nozzle is jammed into the mushroom through hull and soapy water cleans the raw water circuit. I alternate between the two through hulls, forcing soapy water in both directions through the raw water circuit.

This method has been used w/ success for 17 years.
This sounds like what I need to do to improve my outflow. Recently my strainer was covered in a silt like mud.
How long do you pump the mixture each direction?
Do you finish with a clean water rinse?
Thanks for this idea. Iíll report back on my success.
__________________
s/v Grace II
POC: Toronto, ON
PuttingDoctor is offline   Reply With Quote
Old 28-06-2019, 13:52   #13
Registered User
 
wingless's Avatar

Join Date: Aug 2013
Boat: 2000 Searay 380 Sundancer
Posts: 736
Re: Air Condtioner Flushing Frequency

Quote:
Originally Posted by PuttingDoctor View Post
This sounds like what I need to do to improve my outflow. Recently my strainer was covered in a silt like mud.
How long do you pump the mixture each direction?
Do you finish with a clean water rinse?
Thanks for this idea. I’ll report back on my success.
The process is quick.

My boat permits observation of the exit while I'm forcing water into the other through hull.

The slug of crud exiting happens right at the start, followed by the appearance of fresh soapy water. I do about two minutes in each direction. That lasts months of 10-25% usage.

Yes, I set the Salt Away mixer to soap, w/ ľ cup of soap, running until it has been dispensed, running just fresh water through the system.

If required, I also clean any hull staining from dribbling below the through hull using FSR at that time.
__________________
2000 SeaRay 380 Sundancer Mercruiser
454 MAG MPI Horizon 380hp / Westerbeke 7.0KW BCGB
many cool mods
wingless is offline   Reply With Quote
Old 28-06-2019, 15:06   #14
Writing Full-Time Since 2014
 
thinwater's Avatar

Join Date: Nov 2008
Location: Deale, MD
Boat: PDQ Altair, 32/34
Posts: 6,392
Re: Air Condtioner Flushing Frequency

Quote:
Originally Posted by wingless View Post
My concern w/ doing any non-ABYC modification like this regards possible / unlikely failures.

The insurance company will do a forensic analysis of any significant loss. If they can point at this causing the loss to avoid coverage payment then this non-ABYC modification is too great a risk.

That may not be the whole story. I have GH fitting too, but it is on a T with an isolation valve in between. There is a plug in it when not in use. I believe this is what he is describing. No violation.


If he means GH straight to through hull... that's a different matter.
__________________
Gear Testing--Engineering--Sailing
http://sail-delmarva.blogspot.com/
thinwater is offline   Reply With Quote
Old 29-06-2019, 09:17   #15
Registered User

Join Date: Jun 2019
Posts: 27
Re: Air Condtioner Flushing Frequency

I have lots of stories about this, as I do it for a living, the main reason for flushing a seawater condenser is a rise in head pressure in during cooling, caused by an obstruction/growth, the frequency is dependent on the total continuous run time and the location of the boat with regards to marine life/sediments.
I have seen boats in deep water marinas go many years with zero growth, I have seen boats on a silty seawall with 5000 lbs of mussels on the dock need a cleaning every year.

Keep in mind that every time you chemically clean a condenser you are shortening its life.

Also keep in mind that if you have a bronze impeller in your seawater pump it is consumable.
Most of the large yachts I work on have the AC running 24/7 and the pumps are serviced every year to a year and a half or so.

The best way to clean them is to remove the hose from each coil and clean them each individually, using a 5 gallon bucket and a circulation pump, for 15 minutes or so.

Theres lots of info on the web about the effect of various chemicals on CuNi tube and shell condensers.
__________________

Coolerking is offline   Reply With Quote
Reply

Tags
enc, flushing

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
Head flushing overboard through air vent Howler Plumbing Systems and Fixtures 20 29-09-2018 18:32
wave frequency, rolling frequency? er9 Seamanship & Boat Handling 6 14-09-2017 12:11
Marine Air Condtioner - Cost to Install? Target9000 Electrical: Batteries, Generators & Solar 33 06-01-2010 18:51



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 14:25.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.