Size of hanging locker at captains desk MKI vs MKII A/C install

[Sundance]

So I was measuring the hanging locker in preparation for adding A/C to the boat in the spring.  I was surprised to see that the dimensions are generally 13-1/2" x 19-1/2" which does not accommodate any of the 16K A/C units I have looked at. If I go to a 12K unit it is much closer, but wanted to hear from others who have the A/C in the hanging locker.  If I remove the wood sides, I can gain 1/8" to the aft side and maybe an 1" to the front if I remove the spaces that are glassed in, but there are electrical runs I'd have to work with.  Also, if I remove the wood panels, it opens up more area which is open to the hull therefore increasing the amount of air I would pull from that area as opposed to the cabin area. 

I know A/C has been written written about a lot on this forum, but am left scratching my head about the hanging locker install.  If anyone has a MKII with a hanging locker install, I'd love to see pictures.

[glennd3]

https://c34.org/bbs/index.php/topic,10151.msg78034.html#msg78034

I just installed a 12k dometec turbo in the locker next to nav in a 1990 mk 1.5, please see link for pictures. The ac supplier said that the 16 k was to much for the 34. The reason was that the units are very efficient and would end up short cycling and not removing the humidity. I will say the 12k works fine on the Chesapeake on hot humid august days.

[Sundance]

Glenn - So I did see your install, very nice.  I have a couple questions. 

Did you have to do any fiberglass work to "seal" the locker from the bilge area? 
I've looked at the Dometic Turbo units and unless I'm missing it, they are just A/C, no heat option right? 
Since here on the Great Lakes we don't discharge our waste overboard, I was going to use the macerator thru-hull, do you see any issues with this?
Finally, is there anything in hind sight you wish you had changed or done differently?

[glennd3]

I had the unit installed, I did not do it myself.
There was no fiberglass work done in the locker.
I believe they are also heaters, I have not used it that way.
The thru hull needs to be as low as possible.
Also the strainer need to be below the pump, not sure there would be room using macerator thru hull.

SEAWATER SYSTEM 1. Install the seawater scoop thru-hull inlet as close to the keel and as far below the water line as possible, facing forward. Bed the scoop with a marine sealant designed for underwater use. 2. Install a bronze, full flow seacock on the seawater scoop thru-hull inlet. 3. Install a seawater strainer below the level of the pump with access to filter. 4. Mount the pump above the strainer and at least one foot below the waterline. 5. Connect the seacock and strainer with an uphill run of reinforced marine grade hose. 6. Connect the discharge from the pump uphill to the bottom inlet of the A/C unit's condenser coil with 5/8" (15.9 mm) reinforced marine grade hose. Connect the discharge from the condenser coil to the overboard discharge thru-hull fitting with 5/8" (15.9 mm) reinforced marine grade hose. 7. Avoid loops, high spots or the use of 90° elbows with seawater hose. Each 90° elbow is equivalent to 2.5' (0.762 m) of hose and a 90° elbow on the pump outlet is equivalent to 20' (61 m) of hose. 8. Double clamp all hose connections with two stainless steel clamps, reversing the clamps. 9. Use threaded seal tape on all threaded connections. 10. Connect all metallic parts in contact with seawater to the vessel's bonding system including the speed scoop inlet, strainer, pump and the air conditioner.
Failure to follow the above procedure will void warranty.
Figure 7: Seawater System
NOTES: 1) THRU HULL INLET, BALL VALVE, HOSE AND STRAINER SHOULD BE SIZED NO SMALLER THAN PUMP INLET. 2) INSTALL THRU HULL FITTING AS FAR BELOW THE WATER LINE AS POSSIBLE. 3) PUMP NEEDS DEDICATED THRU HULL NOT SHARED WITH OTHER PUMPS. 4) AVOID OR MINIMIZE 90° ELBOW FITTINGS AS MUCH AS POSSIBLE, ROTATE PUMP HEAD TOWARDS DIRECTION OF WATER FLOW.

I am happy with the ac system as installed. Having outlets in both births, head and salon works nicely. The only thing I notice is the noise in the salon when the unit is on high. I am thinking I may get the sound shield. When I close the doors on the births I cannot hear the ac unit only the fan noise. A feature I did not realize the unit had is that the fan will continue to run, at adjustable speeds, while the ac is off because the temp is achieved, keeps the births nice while doors are closed.

[glennd3]

The unit is also a heater, used it today.

[Roc]

Jeff
Did you try taking the cedar panels out?  That might give you a couple inches here and there.  No need to keep them if you're putting an A/C in there.

[Sundance]

Roc - I did take them out to see what I gained.  In the aft you gain about 1/8" and forward you gain about 1", but in the front there are glassed in "spacers" keeping cedar board from the side allowing the electrical conduits to run in that area.  The biggest difference between the MKI and MKII is that the MKI is fiberglassed all the way to the side of the hull, where the MKII if I remove the panels it is open both fore and aft to the hull.  Great for running the duct work, but poor if you are trying to limit the amount of return air you are pulling from the boat liner area while your A/C is running. 

If there are any MKII's with a hanging locker install, I'd love to see those pics. 

At this point I think we will have to go with a 12K unit, and even with that, only the Dometic Turbo unit fits.  I have until spring to figure it out.

[Geoffreykwright]

I have a friend (with a Cat 36) that removed his forward water tank and installed the AC there - not sure if the unit you are looking at would fit there - but might be an alternative if the hanging locker does not fit....just a thought.

[Jim Hardesty]

Jeff,
Note Shamrocks hull number and my location, both close to you.
I installed AC under the v-berth.  Very happy with it.  Only thing I lost was drawer under v-berth.  Very quiet running, can easily sleep very well in the v-berth with it running. Admittedly, does take longer to cool the aft cabin, if that's what you want.  I think adding an in-duct booster fan would help.
FWIW.  The season after I added AC companion way doors were the next project.  Much easier to keep cool air in and a real nice change.
Jim

[Breakin Away]

My 16k BTU unit is also under the V-berth (with very short ducts to berth area and salon, and a long duct to aft berth). I love it there, because it uses otherwise worthless space and it puts the most air where we sleep and spend our time. Noise is not an issue at all. In our install, we did not lose the drawer under the V-berth.