Marine a/c water flow August 2016

Diann and I love New Bern, NC.  It’s convenient for us to drive our Jeep to visit family and attend to business in Hickory.    Of course, days are a hot 90 degree, high humidity, experience.  A/C for our Gemini sailing catamaran is a must when at dock.  BUT….. the amount of grass and plants in the New Bern Grand harbor is the most we have encountered.  Routine water flow maintenance has become more routine than ever before.

strainer assembly

Marine air conditioners use flowing water to cool the Freon lines as they extract heat from indoors.  On land it’s called air-to-air.  On board a boat it’s called air-to-water.  If your thru hull; water line; or strainer becomes clogged with plant life…… have a problem.

thru hull valve

One has to perform preventive maintenance to insure a properly running a/c system.   The steps usually run:

Shut off the thru hull;

Remove the strainer housing lid;

Remove the strainer;

Empty the strainer;

Reinsert the strainer;

Reinstall the lid;

Open the thru hull;

And turn the a/c back on.

It’s that simple when there’s little debris in the water.  But introduce large amounts of floating plant life and it gets more complicated.

river grass 2

The clump in the above image was removed from the outside of the hull.  And yes, I had to snorkel to find the underwater opening from which I pulled the clump out.

the 3/4 "   pvc push tube was too big for the thru hull opening

the 3/4 ” pvc push tube was too big for the thru hull opening

If that wasn’t enough of a problem, even more grass was impacted in the thru hull fitting.    Like Ronco tv ads- “but, there was more” !  The 90 degree inlet fitting was partially clogged, too.

Without going thru all the details of the effort let me summarize:

A ½” diameter push tube was created from material purchased at Mitchell’s Hardware;

A 3/8” diameter flexible fuel line spare part was used;

As were pieces of stainless steel rigging wire fashioned into grass-hooks to insert into the elbows;

And our wet/dry vacuum saw duty both sucking and blowing!

Two hours later, the a/c was back on line.

I later learned, during conversation at a local boat yard, that our Gemini catamaran’s thru hull assembly is the standard sized part for a 16,000 btu a/c.   My plan for later is to put in an oversized thru hull valve, supply hose, and larger strainer elbow when that project can conveniently be done.  Larger inflow diameter parts will decrease the suction flow resulting from the smaller diameter water pump outflow.

Less suction will mean less grass drawn into the system.  And hopefully an easier extraction of grass for what does come in.  That’s my take on it anyway.

One solution would be to have the boat at a dock without so much grass !  Now, where might that be…………………..

The story / blog of Yacht A Fun, a Gemini catamaran sailboat, traveling the ICW and east coast with insights to the extended cruising life. Gemini Catamaran a/c water flow

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