Air conditioning for 1991 Marine Trader 34 DC

Looking for advice for installation location and ideal size for air conditioning on a 1991 Marine trader 34 double cabin. One or two units? Boat is in the great lakes and is mainly on lake erie. Heat is nice but not used often. Manufacturer suggestions? I installed a mermaid system on a 38 ft morgan sailboat about 10 years ago and was very happy. Do they still build to the same quality today?

Kip were you once a yacht broker in Florida?

A single 16,000 btu unit ducted appropriately should work fine in the Great Lakes.


Webasto is available on line (Defender) and is quite a bit cheaper than the main supplier- Dometic's Cruisaire or Marineaire. Mermaid is probably available on Amazon at about the same price. Both are good.


David

Never a broker. Always been a teacher in Ohio

I have had several Mermaids. Had good experiences with both. Good support when I needed it.

I am new to the "big" boat arena. I have 2 on my 36ft. Marine Trader. One is a cruiseaire and the other a marineaire. Both are original to the vessel. I like the cruiseaire better. 16,000 btu each.

It is nice to have the option of only running the aft cabin if I want.

We have a Webasto 16K (replaced a Cruisair 2015) in our Senator 35. It has done a pretty decent job in our ENC climate. We have a Cruisair 6K forward that does not work which I will be replacing with another Webasto. Our previous boat had a Mermaid; it also performed well. Make sure your ducting is well thought out.

If you were down south I'd say 3 units.

But up north and if you're not planning on having people using the fwd sleeping cabin often you could use just 2 units.

Ocean Breeze

Thanks for the input. I think we'll see what the boat show prices are this winter and buy the most I can afford. Probably going mermaid or ocean breeze.

Just installed a Webasto FCF 16000 btu on our 37' trawler. Vented one so it goes to the master stateroom, the other to the saloon. Works great, a/c and heat. Not too concerned about forward cabin. I can't imagine needing 2 for a 34 ft. trawler. Bought ours from a dealer in Ontario, great price and exchange rate is in our favor. Installed under the settee.

I just installed two 12K Webasto units under the satee in the salon on a 36 tri cabin. I needed 24 K and I find two medium units quieter than a 16 and small unit up front. I have one vent up front, two in the salon and one in the stern cabin. I use the y to balance the system as needed. Tinted windows and blackout shades. Works great in lake Mi.

I don't have A/C on my boat but I've looked into it. My boat is a 34' Marine Trader.

Most suggestions I got were a 5K unit for the forward cabin and a 16K unit for the saloon and master. Unless you are freezing meat, that seems a bit excessive for a boat in the mid-Atlantic region.

My gut feeling was for a 12K in the main cabin with good ducting to the fore and aft cabins. Still haven't done it though so this is just theory.

alormaria said:

I don't have A/C on my boat but I've looked into it. My boat is a 34' Marine Trader.

Most suggestions I got were a 5K unit for the forward cabin and a 16K unit for the saloon and master. Unless you are freezing meat, that seems a bit excessive for a boat in the mid-Atlantic region.

My gut feeling was for a 12K in the main cabin with good ducting to the fore and aft cabins. Still haven't done it though so this is just theory.

Click to expand...

Up north or in the PNW that might work. But in the south you really need the correct amount of BTUs per room to cool a boat properly.

Also the problem with one unit cooling more than one cabin is in one cabin or the other you are not going to have thermostatic control over the room temperature.

Capt.Bill11 said:

Up north or in the PNW that might work. But in the south you really need the correct amount of BTUs per room to cool a boat properly.



Also the problem with one unit cooling more than one cabin is in one cabin or the other you are not going to have thermostatic control over the room temperature.

Click to expand...

True but you can balance the air flow with the flow adjuster in the y junction and with the vents. For me it works great and is quiet.

Up north or in the PNW that might work. But in the south you really need the correct amount of BTUs per room to cool a boat properly.



Also the problem with one unit cooling more than one cabin is in one cabin or the other you are not going to have thermostatic control over the room temperature.



True but you can balance the air flow with the flow adjuster in the y junction and with the vents. For me it works great and is quiet.

I don't have a good feel for the capacity appropriate to Great Lakes conditions.

I've used Mermaid on a couple of boats and can't say enough good things about them - including service (long) after the sale.

Many TFrs (from a thread a while back) swear by Ocean Breeze.

Sizing AC units is a big decision.


Whether in Florida or NJ, if it is 90 degrees outside and well up near or past 75 percent humidity and the emgine just got shut off....even 16K for a main salon full of windows isn't necessarily enough.'


Yes, by the time the engine cools and the sun gets lower....you can chill meat.....but in the meantime....do you want an AC that can do the job?...or have one working overtime just to keep up with being comfy?


Most people do not realize the home sized air conditioner for a nominal bedroom cant be compared to a marine equivalent. Lots of reasons such as air transfer, insulation, windows per cubic foot, etc...etc....

......and seawater temp!

I completed the installation of a Webasto 16k unit recently and it works fine. It went in under the port salon settee. Used a Y duct 5X4X4 with the 4inch ducts going fore and aft. The aft feeds both the salon and aft cabin thru the aft cabin closet with a with a fixed insulated shaft from atop the closet to the the underside of the shelf in the salon where a 30degree supply diffuser feeds the salon. The fixed exposed shaft has a 4"dia supply diffuser for the aft cabin. The other 4" duct runs thru the engine room below the electrical cabinet thru the front hanging locker and up to a 4" supply diffuser for the front cabin. All supply diffusers have dampers that can be shut to divert more supply to other areas. The 4x6 insulated fixed supply shaft is faced with 5/16 teak faced plywood and has 1/2 divinycell rigid insulation inside. Total cost was $1750 plus labor.

I'm going to jump in the pool with you. I am planning on installing the a/c unit in the saloon settee but the first one up by the refrigerator box. The duct would run under the port deck back to the aft cabin, up to the counter over the fridge and forward to the forward cabin. I had centered on 16K myself after trying a home unit.

psneeld said:

Whether in Florida or NJ, if it is 90 degrees outside and well up near or past 75 percent humidity and the emgine just got shut off....even 16K for a main salon full of windows isn't necessarily enough.'

Yes, by the time the engine cools and the sun gets lower....you can chill meat.....but in the meantime....do you want an AC that can do the job?...or have one working overtime just to keep up with being comfy?

Most people do not realize the home sized air conditioner for a nominal bedroom cant be compared to a marine equivalent. Lots of reasons such as air transfer, insulation, windows per cubic foot, etc...etc....

Click to expand...

This! ^^

Unless you're one of those tough-as-nails types who never needs air conditioning, when you need it, you REALLY need it. Don't design for the minimum, design for those hot days. We endured a 3-day heat wave in Eastport, Maine (where even homes and businesses have no air conditioning) and were thankful to find a dock close enough to an outlet that we could run a long extension cord to our shorepower cord to run the AC.

I strongly recommend two 16K systems. You can cool the whole boat using one if it's not too warm, or if you can only scrounge enough power to run one, or if one fails.

The rest of the time, run whichever or both, based on which spaces you're using, or not using.

Carefully consider ducting options. With my boat, each unit blows into it's own cabin, as well as into the saloon. I can close off vents, but usually the balance seems about right.

Another big decision is where to put the thermostats. You don't want them in a "dead" spot with no air movement, a hot spot or a cool spot. Ideal would be some sort of remote you could put wherever you need it, but I haven't seen those for marine units. You can always put off the decision, and try out different locations over the season before permanently mounting it.

2 16K btu units will need a 50 AMP feed

geoleo said:

2 16K btu units will need a 50 AMP feed

Click to expand...

Ended up installing 16k btu ocean breeze unit under the port settee and ran duct to the aft cabin and the main cabin. I have only temporarily mounted the thermostat in the aft cabin since that is where we sleep. We may end up putting a small unit in the forward cabin in the future.

alormaria said:

I'm going to jump in the pool with you. I am planning on installing the a/c unit in the saloon settee but the first one up by the refrigerator box. The duct would run under the port deck back to the aft cabin, up to the counter over the fridge and forward to the forward cabin. I had centered on 16K myself after trying a home unit.

Click to expand...

Yes I have the webasto-16K my 2nd one---you might want to consider the Mermaid 16500 for a lil more output--- call them direct for best price- they might even have a recon unit for you if your lucky--then get all fittings /duct thru SE Marine air in Ft Lauderdale

I have a 1974 MTDC and have a 16000 in the main salon and aft cabin and 5000 in the front. The 5000 struggles and I am considering upgrading to a larger unit. Both of mine are Mermaids.

BillZe said:

I have a 1974 MTDC and have a 16000 in the main salon and aft cabin and 5000 in the front. The 5000 struggles and I am considering upgrading to a larger unit. Both of mine are Mermaids.

Click to expand...

Im in Florida with nearly same boat and my single Webasto 16K unit cools salon and aft cabin to 79 on 92 days with water temp at 90. Havent tried adding front cabin yet --however all locations have diffusers that have dampers which can be closed to add more air to locations where I am.

I have a 38 Monk design Present. New Webasco. 90 degree water with over 90 outside and she will freeze you out when the v Berth is closed. 48 degrees at the vent. Boat poorly insulated. Will cool whole boat at hottest time of day with fan help. The new one supports 3/4 water lines the old one only 5/8, uses different Freon. The new one is a real hoss.

I have the same boat and have two Mermaid units, 16k in the main salon and aft cabin and 5k in the front. On hot days in New Jersey it works hard to keep up. I would suggest a bigger unit in the front cabin and it would probably be perfect.