How can I cool my whole boat?

[scottymags]

Hi all, thanks for previous help with my fuel tanks leaking. Got that figured out with your advice.

This time I need to figure out how to cool my boat. It's a 1979 43' trawler style with two staterooms and a nice sized saloon. We currently have a 12,000 BTU watercooled unit running centrally and pushing air to the forward cabin and saloon. And an 8,000 BTU portable unit mounted in the aft cabin.

In the heat of the day, we can't get the boat under 82℉ at best. Granted, we're in Florida and it's 90+ outside today, but surely it's possible to get the boat colder.

Should I buy another portable for the front cabin or do we just need a much larger central system?

Any advice appreciated.

[DesertAlbin736]

Any chance of getting a covered slip? Would think shade would help a lot if covered slips were available. Ha, we wish it was only 90 out today. Hit 109 on our back patio today, 113 downtown. I'm guessing our cabin, which is ventilated with screened in forward hatch open, and cockpit enclosure with shade screens probably got up to 130 inside today while sitting parked in storage on the trailer.

And please, don't call me Shirley.

[rnummi]

There are too many 16k btu reefers for sale in the used market for you to be hot. CL has EM all the time. In addition you live just north of the Marine A/C capital of the world (Stuart/FLL). There are tons of used marine a/c units on the market at any given point. As to window mount unit. It depends. If live a board without a lot of voyaging, the 350 buck window ac can't be beat with styro or other lowes or HD mount directing air through forward hatch. Every other boat near me at marina has a big ole window unit chugging along during summer. It's a money call. For us poor residents of the sunshine state, marine a/c isn't optional, it's crucial.

[DesertAlbin736]

For us poor residents of the sunshine state, marine a/c isn't optional, it's crucial.

Same here in AZ for folks who keep big boats full time in the marina on Lake Pleasant. Far as we're concerned boating season on Lake Pleasant is over for us from May 1st to Halloween. Which is why we stick with boats small enough to trailer to San Diego or Pacific NW.

Even in a covered slip you'd need heavy duty AC. I would think with all that AC running you'd need 50 amp service? Just startup currents could trip a 30 amp breaker?

Anyway today (Saturday, June 4) is turning out to be one of the most brutally hot days in Phoenix ever, especially for this early in summer. As I write this at 11:30 MST, the Wundergound temperature reading at a reporting station just a couple miles from our house is reading 112. And it's not even noon yet! Today is the worst of the heat for this week, forecast to top out at 117.

[rnummi]

Another option would be to ask Beta Don. He had two micro window units shoehorned into an A27. If it can be done on an A27.....most amazing thing I ever saw.

[Gmarr]

Curious - how does the aft cabin cool? there is probably a better BTU to space ratio - wondering if its cooler in there.

Also wondering if you have open ventilation vents somewhere that are shipping warmer air back in from somewhere else

[rnummi]

I'm thinking the same thing. 8000 btu's should theoretically be able to cool it off. When was the last time it was checked? If nothing else i would check for leaks in the ducting and proper refrigerant level. That being said, I've got an A27 with a single 12.5 btu cooling both cabins and it takes a couple of mins to cool it down.

[denchen]

The old way is to rig awnings so keeping the sun off, or rig up a pump and keep the cabin roofs wet. ``Latent Heat Of Evaporation`` will cool below the temperature of the water.

[DCatSea]

Yes, cool is not only possible on an A27, but also makes it a very des-res.

Our 27FC has a water-cooled a/c unit in the aft port side storage, ducted for'd through insulated 4" ducting to the for'd cabin and to the aft cabin. I have just fired it up for the first time and have been pleasantly surprised by the results. Not exactly ice-box cold, but certainly life changing for hot, humid Chesapeake Bay summers. The Admiral took a comfortable nap in the forepeak over the weekend, so I can safely assume the temperature was comfy.
Evening at full power the thing was barely audible

I will take and post some pics, with details of make and model.

[Beta Don]

The old way is to rig awnings so keeping the sun off . . . .

That's the solution I would look into. They make awnings with fiberglass poles which bend in a 'U' shape and cover most of the boat - Looks like a covered wagon when it's erected

Don

[rnummi]

Don's Marine Salvage, Marine Liquidators, etc. all have marine a/c units (used) that you can plug and play. Typically 800 or so if not less. Mine's been running for 2 weeks now. No problems.

[DougSea]

My quick reaction is that your central AC unit is undersized. I'd seriously consider adding a second unit and splitting the boat into zones. Our 35 has two 7,000 BTU units (actually, the salon unit may be bigger). So that's 14,000 BTUs in a smaller boat. And on a really hot sunny day they struggle to cool the whole boat.

Do you have shades on your ports (Windows)? That makes a huge difference.