Need advice on air conditioning

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Paul Grecay
Posts: 105
Joined: Oct 13th, '05, 06:57
Location: CD 28 1976 "Peapod"
Lewes, Delaware

Need advice on air conditioning

Post by Paul Grecay »

There is nothing like a cool dry interior on a hot humid day when I'm at a dock. I have a Cruisair Carry On which I have just put on Ebay. I just don't like lugging it on board - I want to install A/C onboard. Right now, I am looking at Mermaid units...there are three that I am considering....9.000 btu ... 6,600 btu ... and 5,200 btu. They weigh 53, 55, and 31.5 lbs respectively. They are all about the same size. I am planning to put it in the area under the Origo on the port side of my 1976 CD 28.
I looked through the archives but I didn't see much discussion of the topic on installation. Does anyone have experience and/or recommendation on a brand, model, or capacity? Or suggestions on installation?
I am definitely getting AC....heat and humidity at the dock make me crazy.
don_flowers
Posts: 1
Joined: Jan 21st, '07, 01:34
Location: None now

Post by don_flowers »

I can help you. I need to ask a few questions. Are you able to run a duct forward, or are you simply going to try cooling the boat dumping all the air in the salon. Is it going to be a split unit, or a self contained unit? Are you going to run it at the dock only, or do you plan on adding a gen. set and running it on the hook. If it is going to be installed on a CD28 I suggest a 9000 BTU unit. Are you going to install one with heat as well as cooling? You will have several more questions as to wire size, availability of water for the water pump, attachment to deck, where to install the thermostat, etc., the list goes on. And finally, where are you located, and how do you use the boat? Don
Paul Grecay
Posts: 105
Joined: Oct 13th, '05, 06:57
Location: CD 28 1976 "Peapod"
Lewes, Delaware

Post by Paul Grecay »

I am planning on a self contained unit with at least one duct running to the V-berth. I would only use it at the dock at 115 V...no room for a genset on my CD 28. I am looking at both the cooling only and the cooling with reverse cycle heating. The boat is used mainly for coastal cruising. I am not concerned about the availability of water since there are many options for placement of an intake, pump. Ditto for the thermostat. Right now I am looking at several Mermaid A/C models. Any suggestions are appreciated.

Thanks, Don...............Paul
Boyd
Posts: 403
Joined: May 9th, '05, 10:23
Location: CD 30 MkII

a/c

Post by Boyd »

My boat apparently came from CD with a/c installed. Its a CruiseAir 12000 btu reverse cycle unit. My boat was the boat show Hull #1, so I suspect it was there to keep prosepctive buyers cool while viewing the boat.

This thing is big and pretty much disables two valuable storage areas. The installation was not well thought out and has no ducting. It adds a lot of complexity to the boat. It just dumps air at the sole about mid ships. The inside unit is installed under the port berth and the ouside unit is in the port cockpit locker. Even with out ducting it does cool the boat but the temperature differential between the sole at the outlet and the V berth is substantial.

In cooling mode it does a good job even on a sunny muggy Florida day. Sure is nice when tied to a dock to pull the humidity out the boat after a few days sailing in the Keys. Another added benefit is the privacy it offers at crowded docks. Closing the boat up gives you space from the dock walkers and gawlkers. Its nice to get a good nights sleep after several days of sleeping in August heat.

On the heating side the reverse cycle is not as effective. I was in Georgia for a while duing a winter and all it would do is take the chill out of the air. The PO had a small space heater on board to make up the difference. When the boat was closed up and the heat on the hull below the waterline would sweat quite a bit.

All in all I will chuck the thing when it quits and probably will not install another unit. If I do replace it, I will get a very small single unit and put it high in the hanging closet so it cools the V berth. The dehumidifying function is more important to me than the absolute cooling. A couple of good fans help out a lot.

Most cruisers without gensets laugh at the idea of air conditioning and think its a useless item. I since I dont have a generator or room for one, I agree.

My boat has a 30amp shorepower connection. With a/c running I can run the 20amp battery charger and misc items without tripping the main. The water heater, battery charger, and a/c together will trip the main. To heat water for a shower, I have to turn off the battery charger or a/c.

Boyd
s/v Tern
CD30 MkII
Fort Lauderdale, Fla.
Steve D
Posts: 19
Joined: Jan 7th, '06, 07:26
Location: Cape Dory 33

AC

Post by Steve D »

I think Zieda had the best idea. She installed a roof unit in the main salon hatch. She permantly attached it there and offers great AC and does not take up any interior space. Precious space that it is.

Steve
Chuck
Posts: 145
Joined: Mar 27th, '05, 14:49
Location: CD30 Cutter, "To The Moon"
Galveston Bay, TX

AC Questions

Post by Chuck »

Paul,
I, too, have installed the Mermaid, 12000, reverse cycle, in our CD30, three years ago. So, one important issue you need to know about. There is a switch in it called a contactor. It is in the control box that can be mounted "anywhere". It is controlled by a 12 volt transformer, and is magnetic, so when the thermostat tells it to turn on the compressor, the magnet kicks in hard, in order to make a positive connection. It is very loud. It will wake you up at night. It seems to be even louder in the heat mode. I called Mermaid's technical dept. and their technician said it should not be that loud, and he would send me another part. He called back, and his boss would not warrant the part, "because it was still working". so, I paid for the contactor. The new one wasn't any better. I have insulated the control box, wrapped it in sound board. Done everything they suggested. It is still a nuisance.
Crusiair's controls do not use this type of control. I can't explain what they do use, but there is a big difference. The Mermaid does cool the boat wonderfully. More than enough BTU's. But I'll be glad when it dies and I can justify buying the Crusiair. PS: another Fleet member here has the same problem with his Mermaid. "Very annoying".
Now, on the location. Another member of our Gulf Fleet has a CD28, of about the same year as yours. His AC is located in the Starboard hanging locker. And I could probably put you in touch with him if you wanted.
Best wishes and good luck.
AC is a very worthwhile investment. It was the very first thing I did after buying the boat. All your projects go better, both inside and outside the cabin.
Chuck
Gulf Coast Fleet
Chuck
Paul Grecay
Posts: 105
Joined: Oct 13th, '05, 06:57
Location: CD 28 1976 "Peapod"
Lewes, Delaware

Noisy relay

Post by Paul Grecay »

Thank you for advice...I will investigate Cruisair as well. I liked the Mermaid unit because of the small footprint and the fact that they are bundled into a single unit.
The contactor sound you describe can be a problem with mechanical relays. You may want to try mounting the relay so that it is not solidly affixed to the bulkhead or fiberglass. There are sound insulating mounts that are very effective for this....they are actually designed along the same line as motor mounts, but they are small. Also, you could replace it with a solid state relay which is silent. Have you investigated Cruisair? What unit are you considering? Cruisair is a good company...I just listed my carryon on ebay...I would keep it but I can't stand carrying it aboard...I want installed AC.
Chuck
Posts: 145
Joined: Mar 27th, '05, 14:49
Location: CD30 Cutter, "To The Moon"
Galveston Bay, TX

solid State Relay

Post by Chuck »

Paul, I have discussed this with an Air Conditioning professional that I have know for years and the electrician I use in my business, with no answers. Could you steer me to the solid state relay? Where would I get one? I have already changed the way the control box is mounted, with foam behind it.
Chuck
Chuck
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Derek Matheson
Posts: 52
Joined: Sep 21st, '06, 08:07
Location: 1981 CD28 #282 Gaelic Gal

Noisy relay

Post by Derek Matheson »

Chuck: Have your marine electrician look at this SSR (contactor). http://www.power-io.com/products/hda.htm. These are silent. Be sure to fuse appropriately.
Derek M.
Chuck
Posts: 145
Joined: Mar 27th, '05, 14:49
Location: CD30 Cutter, "To The Moon"
Galveston Bay, TX

SSR

Post by Chuck »

Derek,
Now this is what I needed to know about. I went to that web site, but will have to get all the details off the existing relay in order to move forward.
Thanks very much.
Chuck
Chuck
Paul Grecay
Posts: 105
Joined: Oct 13th, '05, 06:57
Location: CD 28 1976 "Peapod"
Lewes, Delaware

Mermaid or Cruisair . . . which is better?

Post by Paul Grecay »

Thanks for the advice....it sounds like Chuck has better insight into these relays than I do. So now I am trying to decide which a/c to install: Mermaid or Cruisair? I would be very interested in what people think of these two.
Bill Michne
Posts: 69
Joined: Feb 7th, '05, 07:25
Location: CD 40, Mintaka, Oriental, NC

My two cents...

Post by Bill Michne »

I installed a Mermaid, 16,500 BTU. I have only one air delivery duct, and we use a small fan to circulate air into the V-berth where we sleep. The system is very effective for both cooling and heating. The relay click does not bother us. I did the installation myself, easily saving an amount equivalent to the cost of the unit. It's been in for maybe 6 years with no problems whatever. I would install the largest unit that fit the boat and the budget. My only experience with Cruise Air is with the portable unit. It did the job, but took awhile to cool the boat (Chesapeake Bay at that time). I also didn't like hauling it around. Overall, I think you will be pleased with either brand, permanently installed, as it will dramatically enhance your enjoyment of the boat and the number of times you can use it.
Bill Michne
s/v Mintaka, CD 40
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