Keeping cool, what do you do?

[Craig Cook]

I'm very curious what others do to keep their boats cool enough to sleep on in the summer. I have added two 110v fans and a 12v oscillating fan to at least move the hot air around but it's impossible to sleep in the aft cabin on a hot summer night on the north coast.
It's not practical to sleep in the cockpit, the mosquitos would eat you alive. We had a carry-on AC unit from West Marine that we could install in the forward hatch over the v-berth on the Island Packet, but it really didn't do that great of a job. It was also heavy, awkward and it leaked badly if it rained. The round forward hatch on our 27 really doesn't lend itself well to that design anyhow. There is an h33 owner at our club that has a portable home unit, they vent the hot air out one of the ports but they say the unit is pretty loud and to be honest, I'm not sure where we could put it except maybe the head?
Is it practical to even add marine air conditioning to a boat this size? We have tons of locker space to put the unit (I think), but I don't want to spend $2,000 either.

 

[centerline]

dont under-estimate the power of a simple wind scoop in the hatch.
properly made, they are the most efficient and cheapest solution to warm weather ventilation and cooling.... even the slightest outside air movement can allow a large draft thru the boat, depending on the size of the scoop... with air coming it, it carries the built up interior heat away... the strong breeze inside is refreshing.

I had some extra material from a project and thought I would sew one up, just because I wanted to try one without spending $50.... and I can say that they are well worth the 50 dollar price tag, and move more air and much quicker and quieter than any $50 fan you could reasonably install on the boat.
the only downside is the wind scoop does take at least a little bit of air movement to operate, and there are those days that are too calm for comfort.

 

[Skipper]

When we were in the hot, I put a $100 little window unit in place of the bottom hatch board. With the other boards on top of it, and a couple towels on either side, was air and mosquito tight.
The condensation drooled into the cockpit, as I kept it tilted slightly back, the rear supported by a plastic box. Install time 3 minutes. Stowed in the quarter berth no problem.
We have a 30 footer and it kept it cool. I assisted the AC with a fan midship to push the cold air forward, and cracked a forward top hatch to let the hot out. It took a good half hour to cool the cabin on the really hot Annapolis days, and it cooled about 20 degrees max under outside temp, but 80 vs 100 is bliss. On the 80-90 degree days it was like a posh hotel bar in there.
Also canvas helps big. Any canopies over the cabin will limit the top daytime temps in there, enabling a cooler cabin at night.
We came back to SoCal so excessive heat, humidity, and bugs are no longer an issue. Left the AC in Virginia.

 

[seadaddler]

Many put a portable window in the companionway and they rig up
it to fit and they say it works very well but a pain to get in and out of the boat.

 

[kloudie1]

I used a little 5000 BTU window unit in the companionway for a couple of years. It works to sleep at night and here on the Gulf coast, it can get really hot.. I got tired of stepping over it when it was there and tired of stowing it when out sailing.. I put in a self contained 12000 BTU unit and it is really nice ..
If you install the unit and plumbing and electrics yourself, you can keep the cost to under $2000.. but if you have a yard do it, you'll blow past that number. For your area and your boat, a 10000 or 12000 BTU unit would make you smile.
EDIT in your area, you may have a short enough hot season that the companionway unit may fit your needs..

 

[Benny17441]

Well you have mentioned most of the options and at some point you are going to have to decide which one may allow you to enjoy your boat at night or whether you give up an stay at home. The cheapest and best performing unit is a 5,000 btu window unit that you can place in the companionway. The drawbacks are having to climb over it when getting in and out of the cabin and the fact that it will blow hot air and drain it condensation into the cockpit. The portable units are inefficient they blow hot air out of a 4 1/2" hose that radiates heat and the displaced air gets substituted with more hot humid air from the outside. I like the carry-ons as they can mount on a cabin top but they do leak rain and condensate down. Figure out how many nights you are planning on spending aboard in the summer and if it is less than 10 I would run a window unit. They can easily be ran at anchor with a portable gas generator. Place an awning over the boat as the air between the awning and the cabin top will maintain the deck cooler. Spray water with a hose over the cabin top and deck as the evaporative effect will also cool. you want to try to get the cabin top to ambient temperature and not the 20-30 dgrees above it that direct sunlight can deliver.

 

[njlarry]

Second the wind scoop and awning over the boom. I also open the cockpit locker at night to let engine and fridge heat escape from the hull. May add ac at some time in the future but for those few really bad heat waves it is more comfortable at home.

 

[centerline]

the AC solution works well for cooling... there are portable home units that set inside the boat, and only need their vent tube exiting the boat... but as nice as an air conditioner is at home, when I go to the boat I go anchor out and away where there is no noise or power to run an AC... which is why I suggested a wind scoop,

Second the wind scoop and awning over the boom. I also open the cockpit locker at night to let engine and fridge heat escape from the hull. May add ac at some time in the future but for those few really bad heat waves it is more comfortable at home.

I agree... I go to the boat to unwind, relax and go anchor out away from the noise, an air conditioner, which would require me to be tied to a dock or noisy generator defeats my entire premise of owning a boat.
but maybe, when I get rich and have a full live-aboard crew to maintain all the systems on the extremely large Yacht that I would buy, I might check in to that "AC on the boat" idea

 

[Craig Cook]

I have seen a couple of folks use a home window unit in the companionway, unfortunately that isn't an option for us. The companionway on the 27-3 is very small.......I mean VERY small width wise. The bottom hatch board is roughly 14" wide by 6" tall, the center hatch board might be 18" wide. There would be no way to install a window unit and still be able to use the ladder to get in or out.
It would also be rare, I mean very rare that we would anchor out and stay on the boat. In our area there is only one place to anchor without fear of getting run down in the middle of the night. It is across the bay from our club in the middle of the state park marina. Staying on the boat there means you are buttoned up inside with hatch screens in place. The mosquitos are unbelievable (we had a slip in the park marina for many years). When we stay on board we are at the dock, shore power plugged in.
I appreciate the thoughts, the wind scoop is an idea for sure but even that gets you almost nothing in the aft cabin. The awning has potential as well, I have a light colored canvas drop cloth that would work as an experiment. If it works well I could easily fabricate one from light colored Sunbrella.

 

[Justin_NSA]

You're up north so you won't appreciate A/C as much as we do further south. Marine air is the only way to go. Ours also provides heat which might make the installation more cost effective for you overall. 27' is not too small to enjoy 3 seasons of staying aboard your boat.

 

[Keith13315]

We are almost always comfortable with the hatches and ports open with the fans going. When we get the high humidity we have a Cruise Air for the hatch. As far as leaks yes it does. I made a rain cover like an umbrella it work well. We are in Lake Michigan which is cooler that Erie but not that much.

 

[philwsailz]

8K BTU permanently mounted through bulkhead. Hot side in aft lazarette:

 

[Craig Cook]

That would not work for us Phil. Our 27-3 has an aft cabin on the starboard side so there is no area to mount a unit. The port side is the head area with the holding tank directly against the aft bulkhead of the head in a very small lazarette.

 

[Sailm8]

For us in SW Florida this is our winter. We day sail but overnight means a marina and the built in A/C. Come September we are back at it. The water temp is in the 90's so the interior of the boat is roasting.

 

[Kings Gambit]

For us in SW Florida this is our winter. We day sail but overnight means a marina and the built in A/C. Come September we are back at it. The water temp is in the 90's so the interior of the boat is roasting.

We used to live in St. Petersburg, FL. Our Labor Day weekend "sail out" (September is generally the hottest month in FL) was to leave Bayboro by 0900 and actually sail on the southeast wind the 9 n.mi. or so across Tampa Bay to Bahia Beach (arriving no later than 1130), get a slip, then check into the marina hotel there, and spend the weekend in the pool w/ my beer and cozy (and happy wife), and in our air conditioned room! Typically went with another couple on our boat (but got separate rooms). Did the reverse going home; timed to arrive back at Bayboro by the appearance of the late morning/afternoon thunderstorms. The brackish waters of lower Tampa Bay are not so buggy as further inland, so it was possible to anchor out some nights there and sleep in the cockpit. Nighttime thunderstorms, some very strong, were much more worrisome to me than the bugs or the uncomfortable warmth and humidity. But generally, as Sailm8 pointed out, the mid-fall, winter, and early to mid-spring (i.e., mid-October to May) is the sailing season in SW Florida, and a very nice one at that! Nice winds, cool temps, "pop-up" T-storms rare, and much less insect vermin around.

 

[thinwater]

For us in SW Florida this is our winter. We day sail but overnight means a marina and the built in A/C. Come September we are back at it. The water temp is in the 90's so the interior of the boat is roasting.

My AC unit says it cuts off when the water temperature hits 90F. I never checked to see if the set point was adjustable. Is that a big problem there? Some Chesapeake waters do get into the low 80s late summer.

 

[Kings Gambit]

It's not practical to sleep in the cockpit, the mosquitoes would eat you alive.

There might be solutions to this far easier than rigging for AC--such as enclosure netting. I imagine the campers have solved this problem for themselves--perhaps check out what they use and how they use it.

 

[markwbird]

I have found that living in the SF Bay area really keeps the boat cool.

 

[Sailm8]

My AC unit says it cuts off when the water temperature hits 90F. I never checked to see if the set point was adjustable. Is that a big problem there? Some Chesapeake waters do get into the low 80s late summer.

I have never had mine shut off. Don't know if there is a setting or not.

 

[Thomas Nowak]

I have a Marine air system installed. Honestly would not be able to stay on board without it. A lifesaver for sure.