Retrofit Air Conditioning on a '96 250?

C

chazaroo

New Member
Dec 4, 2006
415
Florida
Boat Info
1996 Sundancer 250
Engines
single 5.7 w Bravo III
We're thinking about having A/C installed. We'd rather not go to a hatch A/C. This brings up several questions. What brand is best? What size is needed? Where do you put the unit? Has anybody been through this?

Chazaroo
 
I helped a buddy of mine do that on the exact same boat a few years ago. As I recall, his was a 5000btu Marine Air unit. I don't remember if it was a reverse cycle (heat pump) or not. It was mounted in the cabinet under the sink - it was snug but it did fit.

There was very little duct work involved as it was all contained in the cabinet. There was a vent facing forward and another facing toward the aft cabin and the return was located in the bottom of the cabinet door.

The water discharge was very short - on the hull right behind the unit. This location is also very convenient to the AC panel. The water pump was located in the forward part of the bilge and the strainer and pickup thru-hull was very close to that.

All things considered, it was a fairly straight-forward install. Only downside is giving up the storage.
 
Thanks! That's a big help. I do have two other questions. First, is your friend happy with the performance of the unit? Second, do you remember how long it took you to do the install?

-Chazaroo
 
Eric,
Yeah, I just found that myself on the Marine Air website plus there's a rebate offer there. Sounds like a great solution! But do you think 3500 btu is big enough for a 250?

-Chazaroo
 
The new 240DA's use a 7000btu unit from the factory. I'm not sure how much cabin space the older 250DA has relative to that but I wouldn't put in anything smaller.
 
Good point about the BTUs. I guess it depends on how hot it is outside and how cool you want it inside. Certainly, it's not enough to cool the cabin "Texas style", ie., "within an inch of your life" (to quote from the book "The Right Stuff").

Maybe get two of those small 12V puppies..... :smt017

On the other hand, this summer money is tight so we're going to try out the gizmo that turns an icechest/cooler into an air conditioner of sorts. It's called Koller-Aire, $40.

http://www.kooleraire.com/kooleraire25.htm
 
I put a call into Marine Air to find out about the DC unit. It sounds like a great solution but I'm afraid I'm going to find out it doesn't have enough power. We'll see.

Chazaroo
 
chazaroo said:
Thanks! That's a big help. I do have two other questions. First, is your friend happy with the performance of the unit? Second, do you remember how long it took you to do the install?

-Chazaroo
Click to expand...

Very happy - you could hang meat in there in short order. The install time was broken up into different segments and I wasn't there for all of it, but I'd say it was probably around 10-12 hours total. There are alot of different things to be done and of course some of it requires the boat out of the water.

As to the size, I think you'll find 5000btu to be plenty for that boat. My 270 has a 7000btu, but the cabin is a little bigger. You might not have room in that cabinet for a larger one anyway. Be aware that it is possible to get too large a unit - if you oversize your unit then it doesn't cycle properly. I'm not an AC expert, but as I understand it the problem has to do with not removing enough moisture (humidity) from the air.
 
MLauman said:
Very happy - you could hang meat in there in short order. The install time was broken up into different segments and I wasn't there for all of it, but I'd say it was probably around 10-12 hours total. There are alot of different things to be done and of course some of it requires the boat out of the water.
As to the size, I think you'll find 5000btu to be plenty for that boat. My 270 has a 7000btu, but the cabin is a little bigger. You might not have room in that cabinet for a larger one anyway. Be aware that it is possible to get too large a unit - if you oversize your unit then it doesn't cycle properly. I'm not an AC expert, but as I understand it the problem has to do with not removing enough moisture (humidity) from the air.


MLauman is correct.
Air conditioning consists of temperature reduction and humidity removal. If you reduce the temp too quickly, you'll get cooler, but clammy air, which is not comfortable. Ideally, temp and humidity is reduced proportionately. it is better to undersize a little than to oversize at all.
Follow Sea Ray's sizing guidelines on their boats, and you'll be pretty much on target.
About 5 years ago, I had gotten a quote on A/C for my 26 Cruisers right in the $3000.00- $4000.00 range, installed, which I thought was reasonable.
Considering inflation, figure more $$$, and realize that there is a through hull penetration below the waterline for cooling water, and another above the waterline for discharge.
 
Just another two bits: we put a 6500 BTU by Flagship Marine in our 240 DA last year and it is just enough to keep things nice down below on a hot and humid Midwest day. Flagship makes a nice unit. All stainless frame and condensation pan, and the compressor does not sit in the condensation. Small rotary compressor, very quiet. Prices are good to boot. Go to the bottom of the linked page.

http://www.flagshipmarine.com/selfcontained.html

Good luck with the project!

Cheers,

Jim
 
What I've found out so far:
*The new 240 DAs come with a 7000 BTU unit when you order air.
*The new 240s look to be the same size as my 250.
*This pretty much rules out the 3500 DC unit mentioned earlier in this thread.
*Based on that it seems anything under 6500 probably won't do the job considering I'm in Florida and it does get a tad warm here in the summer.
*Flagship Marine, the manufacturer that Jim mentioned is about half an hour from my house.

Things left to figure out: What's the best brand? And how much is the install going to cost? (I mentioned doing it myself and my wife indicated she would rather I sink the boat and call the insurance company because that would be less aggravation.) :smt043

-Chazaroo
 
Chazaroo,

You have indicated that you are not going to take on the installation, but download the following PDF if you would like to have a good read on what all is involved. We did not buy Mermaids unit, but this installation guide is very comprehensive and well worth at look see.
Also I would comment that in addition to making a very fine A/C unit the folks at Flagship were great to work with. The A/C install on a 240 DA is not an easy task. I needed two things customized on our unit for the best possible install. I needed a custom variation of the discharge plenum, and the condensation drain needed to be on the opposite side from standard and they accomplished both requests without complaint, or extra charge. FYI

http://www.mmair.com/content/download/113/457/file/OWNERS GUIDE 02-10-06.pdf

Cheers,

Jim

P.S., Flagship also offers a 9000 BTU unit, same dimensions as the 6500 BTU, and only $200. more.
 
Jim,
Thanks for the info. I'm thinking 9000 is too much for the boat. So the 6500 is probably about right. How cool does that keep the 240 and at what outside temperature? In summer here, we're typically looking at temps around 93 with farily high humidity.

Chazaroo
 
Heatercraft makes a air to air marine A/C unit.

For smaller older cruisers on a budget looking to do a self-install that wish to avoid the portable hatch system yet are not ready to drill holes in the hull below the waterline it fits that need.

No winterization needed. 10,000 BTU Heat or 8,000 BTU A/C.

Linky

http://www.heatercraft.com/category.aspx?categoryID=6

I dont know the $ cost. I looked but could not find. Sorry. If anyone knows please post.

Update: Air Fusion unit = $1,250. Then add any batteries /inverter / hardware duct / etc.
 
chazaroo said:
Jim,
Thanks for the info. I'm thinking 9000 is too much for the boat. So the 6500 is probably about right. How cool does that keep the 240 and at what outside temperature? In summer here, we're typically looking at temps around 93 with farily high humidity.
Chazaroo
Click to expand...

Chazaroo,
The 9000 would be too large. The new 30's, which have a large cabin, have 12000, I believe.
Remember, humidity removal is 1/2 of the equation.
Good luck,
 
It seems to me that how you use the a/c determines how much you need. If you want to keep the cabin cool during the heat of the day, you certainly want to have more. If you just want to have it cool while you sleep, and assuming you sleep when the sun's down, then smaller might be OK.

Cooling off the foredeck with water will help a lot at any time.
 
Chazaroo,

Our late summer weather here is not allot better than what you have in Florida. Low to mid 90's and humidity in the 80% bracket is not that uncommon. The 6500 BTU unit will keep the cabin 76-78 degrees in the peak heat of the day, but it will be running constantly to maintain that. At night we like to dial things down to 70 for sleeping. No problem with that, and the unit cycles nicely.

Doug,

Interesting unit! Never seen anything quite like it. A no-brainer for install compared to a conventional system. The unit size and the 40 AMP D.C. only specs might make it a tough sell in the sport cruiser market though.
Are you in the water yet? We hope to splash this weekend!

Cheers,

Jim
 
Jim,
Looks like 6500-7000 will do the trick.

Erik,
Interesting tip about cooling the foredeck off with water. Thanks

Now I just have to find somebody to put the thing in for a reasonable amount of $$$. That may be the trickiest part of all.


-Chazaroo
 
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