Air Conditioning - RV Roof vs Carry-On

jamesnewsome · #1 (**permalink**) 02-09-2012

Sailboats without built-in HVAC face a real challenge when summer arrives. I've used a traditional CARRY-ON brand 5k BTU unit set over a forward hatch for years, but the results I would describe as barely acceptable.

Frankly, I think the CARRY-ON units/brands are rip-offs. The company just happens to have a good cabinet design that a mostly standard small air conditioning unit is adapted to fit in. I pull mine apart each off season and clean it, and cannot see that there's anything especially "marine" about the construction of the actual AC unit.

Some fellow sailboat owners and I are discussing the possibility of just using a RV ceiling type air conditioning unit and are wondering if anyone else has tried this. A 13.5k BTU unit can be purchased for around $600 and can easily be fitted over a hatch as small as 14"x14."

I look forward to hearing the feedback.

PBzeer · #2 (**permalink**) 02-09-2012

I've never seen rooftop units on anything but houseboats. If you just want it for dockside use, most of what I've seen has been window type units with their own hatchboard, set in the companionway. When they leave the dock, they either stow it on the boat, or put it in their car.

I even saw a sailboat in FL with a hard bimini that had a ceiling fan on it.

lans0012 · #3 (**permalink**) 02-09-2012

It's not uncommon to see the rv style units on boats in the marina. I've never seen one out sailing though with one of those things on it.

A lot of people who don't want the expense or have the space to fit internal AC use a standard big box store ac unit built into the companionway hatch boards. Here's a picture of mine. It's 5k BTU and plenty for my 27 footer on the hottest days and nights. When we're out sailing I just stick it on the v berth. This setup will cost you about 130 with tax and materials assuming you buy the ac unit new. I just cut it into 1/2" plywood board and use some angled brakets drilled right into the shell of the ac unit. Use the spray foam to fill the gaps and you are good to go.

JimMcGee · #4 (**permalink**) 02-09-2012

Quote:

Originally Posted by jamesnewsome

Some fellow sailboat owners and I are discussing the possibility of just using a RV ceiling type air conditioning unit and are wondering if anyone else has tried this. A 13.5k BTU unit can be purchased for around $600 and can easily be fitted over a hatch as small as 14"x14."

I look forward to hearing the feedback.

James, I don't think it's a practical solution. I had a 5K carry-on for a couple of seasons and finally bit the bullet and installed AC on our boat.

The 5K carry-ons are 68lbs. They're a pain in the ass to get on board if you keep it in a dock box. That step from the dock over the life lines is VERY awkward with that much weight in your arms. When I kept it on-board it was a bitch to feed up through the forward hatch (at least on our boat) and I managed to twist my back more than once doing the contortions.

I checked the RV units on one of the RV web sites and the 13.5K units are 117lbs! The site didn't have dimensions (only height) but I guessing from the photo you couldn't feed it up through the hatch. Imagine carrying 117lbs up through the cockpit, then forward over lines and along narrow side decks on a day when it's hot enough to need AC. Remember it's an awkward carry. It's not like a 70-80lb bundle of shingles you can just throw over your shoulder.

Quote:

Originally Posted by PBzeer

I've never seen rooftop units on anything but houseboats.

I think that's why...

lans0012 · #5 (**permalink**) 02-09-2012

I also have a carry on unit that came with the boat. I've actually never used it because it takes up so much space. The 5k BTU window units are a lot lighter. I would say <40lbs including the plywood it's attached to. It also is easy enough to store. It's a pain sometimes to step over it, but the trade off is $s. Built in AC Wouldn't be practical for my boat. If I had a larger boat, I think i might spring for it though. from what I hear, they can be very costly to purchase, install and maintain.

The window unit is built to be half indoors and half outdoors, so like the rv unit it is already "marinized." I can just imagine taking a wave over the boat and have that thing torn from the deck and washed overboard. Although, I have seen the RV units on several sailboats in Tampa Bay, however none actually sailing. Most of the boats just sit at the dock all year. Every now and then someone comes and grills a burger on it and that is about it.

chef2sail · #6 (**permalink**) 02-09-2012

We have used the carry on unit for 7 years with no problems. Whenb sailing it sits on a towle wedged under the filler for the V berth which is inserted. never moves.

When we dock we use the spinaker halyard to winch it up through the forward hatch over the V berth and place it on top of that. No issues. It can be a comical sight when we pull into a marina when we travel as it is part of our post docking routine and we have seen people staring at us as this "beast' emerges getting winched up through the hatch. It works fine and takes the humidity out of the boat..and cools it in the dead of a Chesapeake summer. Takes us 54 minutes. I would rather have built in AC but this works fine.

Dave

JimMcGee · #7 (**permalink**) 02-09-2012

Quote:

Originally Posted by chef2sail

When we dock we use the spinaker halyard to winch it up through the forward hatch over the V berth

Good idea...

MARC2012 · #8 (**permalink**) 02-09-2012

I had the rv type on two trawlers & worked great but on a saiboat think would be VERY much in the way.Had a cruiseair,hated it with a passion,heave,difficult to stow.Kept it in the aft cabin and no matter what i needed it was in the locker under it.Had one regular marine reverse cycle marine unit,forever changing pumps.Now have a lowes win. worked fine 2 yrs & still going.marc

jamesnewsome · #9 (**permalink**) 02-10-2012

I agree that the best option is a built-in unit, but it's also the most expensive and sometimes not possible on smaller boats. I don't think the RV ceiling unit is realistic for use over a forward hatch because (as suggested) it's too bulky. I did check the weight on the Coleman Mach 3 - 13.5k BTU and it weighs in at 108 pounds.

To me the main issue is how much time is going to be spent on the boat and if it's considerable then creature comfort outweighs some of the drawbacks. My objective is finding the most efficient & practical cooling system for the fewest dollars. I really like the idea of an inexpensive residential type unit modified to fit in some opening and I have seen several boats with the units in the main companionway. Not sure I can deal with the restricted access to the cabin.

I do think the RV ceiling unit would work well on a larger boat with a center hatch (under the boom) over the main cabin and may not be in the way when sailing. I've seen folks with a dingy strapped down sailing and these roof-top units are far smaller.

Unfortunately, my boat only has a small 16"x16" hatch over the v-berth.

chef2sail · #10 (**permalink**) 02-10-2012

Our cruise air portable will fit your 16X16 hatch I beleive. You just have to stow it under your filler at the V and make sure it doesnt bang aorund. It is a nice thing to have when in the marina on the Chessie in July when at night it is brutally hot and humid with no air vs anchorage. Using the halyard and set up takes 5 minutes. They are way more expensive now, but there are used ones to be had. e bought ours new 7 years ago for 500 dollars.

Dave