AC questions

I’m not directly answering your questions but on my boat on hot days (not hot by FL standards mind you) I put a small fan in the door of my master strm blowing down the passageway and up the stairs to the salon. My staterooms gets much cooler than the salon and moving that air up and around seems to really help. Especially since the cold air is going to naturally settle downstairs and heat will rise anyway.

The freon type should be on the nomenclature plate on the units, but you probably won't get it at an auto parts store. You'll need a set of gauges to add freon.

You probably have the original R-22 Cruisair units.
Dumetic bought that and other fine companies up. When you can't compete, buy up your competition.
R-22 this not sold over the counter. Expensive as heck for licensed service techs.
Nobody is selling or manufacturing any R-22 equipment any more.
R-410 is current, pending some new refrigerant coming. If it works, count on the EPA to stop it.

I was just talking with Steve at Flagship today. Great guy.
Great stuff, o k prices, not wanting to sell split units unless he has to.
Today,, 4 weeks to build and deliver anything.
He has a self contained, cost reduced brand, for emergencies, that can ship now.

Hot canal water will keep your systems from cooling well.
Restricted strainers also.
I wish you had your AC checked before you started leaving,,, in two days??

Like Capt. Ralph wrote; you probably have R-22 units but that gas is many years out of production and even if you found an AC guy with some you best be sitting when you hear the cost of it. That said; before adding any you need to put pressure gauges on to see if it's even low. My 3 units, including blowers were replaced last year and I found the new blowers from Dometic do a much better job and even on the hottest S. Florida days the boat stays nice and cool. On my previous smaller spt. fish with only 2 units I had the forward salon windshield glassed and that made a huge difference.

My saloon 24Kbtu dies last Wednesday night.
2006 model. Was going to shop for a new Bristol compressor, looked at the fan and decided against fixing it.
I keep forgetting fans take a lot of abuse in salt air.
Tray was toast also.

If your flowing water, no high pressure errors or rapid compressor cycling, don't open pandoras box rite before you start your run home.

November and out of the water is good.
You may end up replacing hoses, reworking the strainer, cleaning up the sea-cock.
I've even found restrictions at the discharge skin fitting.

Oh, that reminds me, does this boat have a common drain manifold? Or each AC has its own piddle stream over the side.

I got things to tell you about on those common manifolds.

@RossC

Nature of the beast, yep.

You've seen external covers -- mesh, Sunbrella, Stamoid, etc. -- can help. Another you might consider in the longer term is interior window tinting, with a product designed for IR/UV filtering. (FWIW, we used 3M Prestige 50 on the front windshield and it makes a good difference. We used Prestige 60 on the rear slider, don't get as much sun there anyway so can't tell degree of difference. Neither obscures our vision outward, and neither is "privacy" tinting. We're now thinking of adding the same tint to some of the side windows.)

Flushing your system with dockwater can sometimes help. Water pressure will force water straight through and overboard... although I think the outcome isn't too much different than running the system on raw water with your existing pump. Still, it's clean water...

Flushing the raw water circulation system with either Barnacle Buster or Rydlyme can work. Both products recommend constant recirculation for best results, but... that's not so easy to do with the boat in the water. Still, I've used the "fill, wait, add more, repeat..." approach with Barnacle Buster and it works reasonably well. A small transfer pump will push solution right through your onboard pump, so it's not too difficult to add a gallon, wait, add another gallon, wait, etc. (Even better in our case would be a valve'd manifold so we could better control flow especially through our "farthest" (bow stateroom) unit... and the valves are on my To Do list.)

We've replaced a couple Marine Airrrrr Vector Compact units and one Cruisair Stowaway unit (so far) with Dometic units that are now called DTGs (descendant from the Marine Airrrr Vector Turbo) and they've been a great improvement. Better air flow, better (composite) drain pan, better cooling overall and worked with our pre-existing control panels (Passport II on the previous boat, SMXir on this one) although maybe we had to order the right unit to get that compatibility. (Can't remember.) Best to order at a time when you can get "boat show pricing" discounts.

The CTM units, same footprint, are said to be ditto all that... including working with existing control panels, and so far estimates tend to be slightly less expensive than the Dometic units. I've read their delivery packaging is sometimes challenged, but also that if the units survive transport everything else is good. As our remaining 16/12K units age out, I'm considering trying CTM...

The original bridge unit on this current boat was delivered as a Cruisair 24K BTU model, don't know product number. We replaced it with a more current Dometic DCU 27-2361-410A unit... which was about an arm and a leg $$$ even with 20% discount... but seems to work OK. Not easy to cool the greenhouse; works better when we close the hatch to the bridge (which you might not have?).

-Chris

We upgraded our window tinting on the salon level 3-4 years ago. Has made a significant difference for us.

Forgot to include:

If you have Groco strainers, Trac (the Barnacle Buster people) offers a lid replacement that takes a garden hose attachment.

Or you can insert a Groco SSC with flush adapter somewhere in your system, either before or after the strainer.

-Chris

Just finished up talking with Mermaid. They make a nice self contained unit up to 24Kbtu also.
Will sell with the U board a lil cheaper than the other shops.
Delivery time a lil quicker also.
https://fmmsusa.com/marine-division/
Nobody has ready to ship units now.