A/C duct locations

[Ed.S]

I have a Hunter Legend 376 which had an after market air conditioner installed prior to my purchase. It was a Mermaid 16,0000
BTU (age unknown). Since I live in Florida on the hot summer days it wouldn't keep the boat cool. The A/C unit has expired and I am replacing it with a Dometic Turbo 16,000 BTU.
When the original A/C was installed they ran the ducts to the salon, behind the dinette, and into the V-berth. There is no air going into the main cabin. I see on the Hunter details that the duct can be run under the freezer/refrigerator, stove and into the starboard rear hanging closet.
Does anyone have experience installing this duct and can you give me some instruction before I start drilling into the cabinets.
Ed S
s/v Privateer

 

[SycloneDriver]

I have that exact 16k BTU unit on my 31ft boat in Oklahoma. It replaced a failed 12k BTU unit. I also increased the duct size in the salon from 4 inch to 5. I am currently having covers made for all the ports/windows/hatches. I doubt that a single 16k unit will be enough on a 37ft boat in Florida.

Got to love Climate Change.

 

[Ed.S]

Thanks SycloneDriver, I know the A/C will be marginal. I am actually looking for information on running duct work to the rear cabin on my Hunter 376.
Ed.S

 

[Crusty Ol Salt]

Do you need vents into your main cabin? if the unit return is located in the main cabin all the returning air is drawn thru it.

 

[Capt Robbie]

Ed. Before rerouting ducts try installing an in-line fan to increase your CFM

I have the same unit on my H34 and had very little air flow to the v berth due to the long run and resistance in the flex ductwork. I installed it about six feet from the vent and it works great. Only about $30 at lowes.

before putting a 16k unit in, if you have the room and electric available you might want to get the next size unit up. Mine struggles on really hot 90 plus days and your boat has a little more cubic volume then mine and no insulation,
Florida heat and humidity is brutal

hope this helps

 

[Ed.S]

Thanks Crusty Ol Salt, (like that name) My unit/return air is located in the salon. so no air is directed to the aft cabin. I use fans to get some air back there but that doesn't work very well.

Thanks Capt Robbie, I have good air flow to the V berth, no duct to the rear cabin. I looked at installing a larger unit but the space is too small.
Ed.S

 

[sailcapt340]

On my 340 I have the same Mermaid Unit you had. It has worked perfectly for us, when we are in a slip, but it gets no where near as much use, as you would use yours in Florida. Well, maybe this year.
I have a vent in the main cabin saloon, head and aft cabin. None in the V berth.
You should not have any fiberglass walls you have to bore a hole through, but you will need a good new 4 or 5 inch hole saw for the holes you do have to drill. And be prepared for the dust! There will be dust.
I’ve included some photos of my install for you to look at and the Y connect fitting to send the duct work off in another direction.
Make sure you have a clear line of sight before you start drilling, especially under the refrigerator as you described. In the hanging closet there may be your exhaust hose for the unit and other electronics behind the removable wall. Look there also, mine are in there.
Other than that, take your time.
I hope this helps in some way for you.

 

[Ed.S]

Thanks sailcapt340, My arrangement is a little different but the bottom line is like you said measure, measure then cut very carefully. I wouldn't want to cut a hole in my freezer compartment. There isn't anything in the hanging closet so all clear there. My biggest concern is drilling between the back of the dinette settee and the freezer compartment. There is a propane gas line feeding the range that I will have to deal with.
Ed.S

 

[sailcapt340]

The back of the settee area is probably going to be a fiberglass wall. Not like other laminated plywood walls like in the head area under the sink and behind the toilet.
You'll want a good carbide tipped hole saw or a whole saw rated for fiberglass. Or you will not get through it. The propane line "should" be anchored to the side wall of the boat like mine is. So double check that it's out of the way and any refrigerator lines as well.
Cramped spaces and a lot in them!

 

[Ed.S]

I will be attempting (maybe) this project next week. Slow and easy.
Thanks for the tips Sailcapt340
Ed.S

 

[artboas]

Would like to chime in on something related.
On most boats, they just let the airco pan drain to the bilge. Don’t do this. It puts a lot more gunk & mildew in the bilge.
2 ways to resolve this…
Use either a sump box, or (highly preferred) a Whale IC pump system

Or.,
Put in a Mermaid condensator. These work great, if maintained

 

[Ed.S]

I'm thinking about the Mermaid condensator.
Ed.S

 

[gusmuller]

Ed,

So it has been a week or so since I finalized the ac installation. The duct work was the most difficult part due to space restrictions.
Here are some pics. The strainer was already replaced with a much larger one(clogged in days), the darker image is actually the limited space under the fridge.
I am very happy with the results and the boat is kept at a constant 74F even with the 95F at the docks.

 

[Ed.S]

Gus,
Thanks for the response, I am a little confused what air conditioner did you install I see a picture of a Mermaid and a picture of a Webasto. And where is the Mermaid located, I don't recognize the location. Your installation looks amazing and I'm glad it is working well for you.
Ed

 

[Ed.S]

Gus,
I apologize, Some pictures were integrated from other threads. I see you used the Webasto A/C unit.