Marine A/C installation in a 25

W

WCF

New member
I'm wondering where people have installed all-in-one marine heat pump/AC units in the 25. I do know how to install the unit correctly and the potential pitfalls and have no concerns there.

I have seen one installation in person. I am looking for additional input or photos. I did search many old threads, but did not find much.

The hanging locker makes the most sense to me right now, but almost every cabinet in the boat is an option. I'd appreciate any thoughts on where to sacrifice the space. About 12" H x 14" L x "10 W - The unit does need some room around it but the ducting outlet can be clocked to almost any direction. The water pump I am using is way overkill so height above the waterline (head) is not a concern.

Just to head off everyone telling me what I should do instead:
1) The cabin roof is and will remain occupied. The RV style does not work for me. No offense to anyone else, but I also personally do not like how they look.
2) I have tested a window unit and while it is a really good solution it is not the right solution for how we use the boat.

I have already purchased and bench tested one of the new small 6k BTU reverse cycle units w/ integrated soft start (Designed to run on an inverter.) It seems to produce plenty of cool and heat for my use even when the water temperature is less than ideal.

For anyone that is interested, it draws 800W peak at 115V (Soft start prevents any high loads at startup.) The 800W is with the oversized water pump.
 
I would remove the water heater, and go to one of the small Bosch units under the sink. This does several things. It give a space which is already taken, so no loss of storage. It cuts down the dead space between end use of hot water to almost nil, thus saving water. The small water heaters heat more rapidly, and could be run off an inverter if necessary.

The pickup should be under the step as you go into the boat.

Ducting you want to be in the center of the boat, of if aft, then a second duct, or "Y" to allow a duct to blow into the V Bert area-- this can be accomplished with small fans, open up the port bulkhead and run the ducting out of the back of the front dinette seat, or along the port side near there.

The major disadvantage of the built in water cooled AC, is that it cannot be used when "boater homing", and jelly fish, sea weed, and small marine life can plug the inlet/strainer.
 
I have already moved the water heater. I started with the Bosch but quickly moved on to the Duetto 3, which is a much better form factor and has the option of 12V.

The cabinet that formerly housed the water heater now contains the battery bank.

Yes, the pickup will go under the step w/ speed scoop and seacock.

If using the A/C on the trailer is ever a concern again, I have the window unit or could install a tee for a garden hose. The boat is used 90% of the time in crystal clear freshwater.
 
You’re on the right track with the Duetto 3, much better fit than the Bosch, and the 12V option is a game changer. Moving the water heater to make room for the battery bank was a smart move. For freshwater use, you’ve got it covered, and having the window unit as a backup is a solid plan if you need it on the trailer.
 
I tried putting the AC unit in a few spots over the weekend and have committed to the hanging locker - I will add a shelf so the entire cabinet doesn't get eaten up.

While it doesn't look as fancy, I am very glad I have the plywood interior and not the fiberglass interior; it took a matter of minutes to disassemble the hanging locker and step and open up a work area.

I am reconfiguring the bilge pump to use the hole for the former waste\head discharge, so I will not have to drill any additional above-waterline holes in the boat.

I tested a $8 venturi device for the A/C condensate, and that works great.

Seacock will be mounted on a 1/2 fiberglass plate epoxied in, and speed scoop on a 1/4 plate so no fasteners penetrate the core. This is what I've done on my sailboats in the past and it makes for a sturdy install. Obviously the large hole will have the core removed around the edge and filled with thickened epoxy.

I have a teak louvered vent panel I made for another boat and did not use that will go in the hanging locker door.

Still considering options for ductwork; for now the compromise is to use a fan to move air around the boat just like is necessary with the Wallas.
 
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