Marine AC

[Ekutney]

I plan to install a marine AC unit on my C34, I am a live aboard year round and need a unit that has both AC and heat.  I had reviewed all the installations on this site, there are a number of location choices to include Nav locker, V berth and starboard side setee.  I am looking at a single 16K BTU unit with ducting to V berth, salon and aft cabin.

I have reviewed the product offerings and feedback from a variety of companies to include:
Dometic
Merimaidl
Flagship
MarinAire
Webasto
Ocean Breeze


I am looking for some input on unit selection and installation location.

[britinusa]

I installed the Dometic 16K unit in the V-Berth just a month ago.

Biggest challenge was routing duct. I installed the unit in the V-Berth, Ran the Raw Water from a T in the Head Cupboard and installed a new Thru hull with sea cock in the V-Berth. The Pump is also in the V-Berth.

I installed duct from the unit, down the stbd side into the back of the hanging locker, then up through the hanging locker shelf where I installed a triangular box (2 sides, the bulkhead making the 3rd) That box has a vent into the v-berth and there is a vent cut through the cabin-v-berth bulkhead.

It works really well, but does not pump any cool air into the aft berth. Choice is to figure out how to run duct from the V-berth back to the aft berth or (our plan) to have a pair of fans sucking cabin air into and blowing air out of the aft berth.

I had a Dometic in my previous boat for 10 years, worked flawlessly.

Oh, I installed the AC controller at the Nav Station and the Electronics box in the V-Berth.

I also made a return air grill that fits on the face of the V-Berth bulkhead beneath the v-Berth extension cushion.

Hope that helps.

Paul

[Ekutney]

Paul,

Which Dometic unit?  Cruiseair or Marine Air Systems and which model?

I am looking at duct routing options and it does seem to be a challenge to get air to the aft cabin.   I found the link that showed routing ductwork through the port side setee into the Nav locker through the head into the aft cabin.  This allowed air not only to the aft cabin but the head as well.  Do you think the blower has enough power to push air this route?

Do you have any pictures of your installation?

V/R

[Ken Juul]

For your location, reverse cycle is useless in the winter.  The electric coil heat Ocean Breeze sells works great. When I was living aboard in Pax River, I had to supplement with an oil filled radiator type heater that stayed on constantly.  Kept the boat in the mid 50's.  Home from work turn the OB on and the cabin was a toasty 68-70 in a few minutes.  My boat has 2 units, 6K in the V berth and 12K for the rest of the boat.  The small one is dieing, will be replaced this spring.  It was several years old when I got the boat in 2000, can't complain about over 15 years of service.  Ocean Breeze makes a good product and are very helpful on the phone.  The Thermostat for the newer 12K unit failed.  Called them up, they asked if it was digital or capiliary tube.  When I said digital, they said they would be happy to sell me a new one for over $100, but if it was his boat he would replace it with any home digital thermostat.  Found one at Walmart for about $40. Been working great ever since.  Haven't been shopping in a while, but I think OB is slightly less $$ than the other units.

[Ekutney]

Ken,

I looked at the Ocean Breeze, very similar to Flagship. Both these units have electric heating element which has many pros for liveaboard in the MD area, although this year feels almost like we're skipping winter. 

What is the noise level like and is the fan speed variable?

Do you think a single 16K unit could do the job?

From all the research I've done it seems moving air in the boat has a major impact on quality-of-life. 

V/R

[Jim Hardesty]

I installed an Ocean Breeze 16,500 four seasons ago.  Works well enough, but it does take a while to cool the boat down.  I installed it under the v-berth and ran duct to v-berth, forward salon bulkhead, under the nav table, head, and the aft berth.   Also have fans mounted in the v-berth and main salon.  Something that you should consider is your choice of sleeping cabins.  I use the v-berth so sound proofing was necessary, took some sound proofing panels and fine tuning to get the sound level the way I wanted it.  It's very quiet now.  The v-berth and main salon cools well, takes much more time to cool if the aft duct is open and the aft cabin door is left open.
FWIW I think that shipping caused some issues namely a  damaged coolant feed and out of balance compressor.   Ocean Breeze handled the problems very much to my satisfaction.
Jim

[Hugh17]

I replaced the 12,000 BTU Reverse Cycle HVAC unit on my 1987 C34 when I purchased her three years ago with a 16,000 BTU Dometic unit. Apparently, a previous owner had removed the holding tank from under the port couch, installed a bladder type holding tank in the wet locker/nav table area and installed the HVAC unit.

There are pro and cons to this location, and I'm not sure I would have chosen it if I'd originally installed the system. But it works great and I have no regrets. Since the unit is centrally located I have two vents installed, also in this same locker. One points towards the galley/aft cabin, and the other services the main cabin and V-berth. Again, this was the original installation configuration. All I did was replace the old unit with a larger one.

How would I improve on this? Run a 4" duct to the Head/shower & on to the Aft Cabin for starters, and install an inline blower on this duct to help move the air. I'd also install add a duct headed to the V-berth. All this is easier said than done. There is good way to run duct in this boat without losing valuable storage space.  I've read that running the duct under the floor in the bilge area might work. I haven't studied this, but this would certainly be a viable option to keep from losing storage lockers.

The bottom line for me is that I have an awesome AC unit in the summer and more than adequate heating in the winter. But most of the time we just use a small space heater in the winter. One thing to remember is that reverse cycle units will only work well if the water temp doesn't get too cold in the winter or too hot in the summer. I just happen to be in an area (coastal GA) where the water temps work well both ways.

A picture of my installation is attached.

[Ekutney]

It is very helpful to get performance info on 3-4 years of operation, the knowledge base of the people here is outstanding.

Hugh,
What brand by Dometic, Cruiseair or Marine Aire Systems?

I am leaning towards installing in the Nav locker or starboard side fwd setee, they seem to be a good locations for ducting the air both fwd and aft.  I know it is giving up storage space but I'm inclined not to lose the holding tank.  I've been told the V berth is also a good location but that is a long run for the duct to the head & aft berth.  I think your idea of an inline blower makes good sense.

Jim,
I read the post on the V berth installation, seems like a long run to the aft cabin.  What size duct are you using?

Do either of your installations have good ventilation for the unit or is the supply air vent work to get heat out of where it is installed?

[Hugh17]

I went with the Dometic ECD16K-HV A/C RETROFT.

http://www.go2marine.com/product/384864F/dometic-air-conditioning-kit-w-reverse-cycle-heat-ecd16k-hv-a-c-retrofit-kit-410a.html

[Hugh17]

Ed,

You also asked about the return or air intake. You can see from the picture I posted that that return is the large cutout in the center. Cleaning the filter is very easy. Just unscrew the grill cover and remove the filter. I think the negative to any installation of a large unit is going to be the sound. The unit itself doesn't make that much noise, but there's a lot of air moving and it can be a bit annoying. The fan on this unit has 3 or 4 speeds and I always run it on the lowest speed.

I knew an owner of another C34 and the AC was installed under the v-Berth. It was so noisy that he and his wife would not sleep there. Then the issue was moving the air to the main and aft cabins. His installation sacrificed a large part of the hanging locker on the starboard side in the V-berth.

Honestly, I don't know if there's a perfect answer to the installation of a HVAC unit in this earlier model C34. Any installation is going to sacrifice some storage space, which isn't ample to start with. BUT, any installation is better than no AC!!

[britinusa]

I went with the Dometic ECD16K-HV A/C RETROFT.

http://www.go2marine.com/product/384864F/dometic-air-conditioning-kit-w-reverse-cycle-heat-ecd16k-hv-a-c-retrofit-kit-410a.html

Same here.

paul

[Roc]

You can put the unit under the head sink with the return grill coming from the aft cabin.  Run a duct along port side to v-berth.  Run duct to main salon, exit near nav station.  Small ducts into head and aft cabin (aft cabin optional, as the air is sucked into aft cabin from return duct.  Either keep aft cabin door open, or did what I did, cut out bottom panel and put louvers in that section for air flow.

[Jim Hardesty]

Ed,
Yes, it is a long run to the aft cabin.  Reason for the slower cool down back there.  It's not that important to me, I use the v-berth.  When I have over night guests.  First cool down the rest of the boat, then open the door and ac-vent and cool the aft cabin.  It works.  The duct work is 4".  Here is my invoice from when I bought the AC unit, sorry about the cut&paste.  It does include every thing used except material to build a shelf to mount the AC, sound proofing, and the wiring and circuit breaker. 

Quantity Item Description Unit Price Amount
1.00 OB16CH 16,700 BTU Self Contained Marine AC Unit 1,595.00 1,595.00
(HORIZONTAL)
1.00 Plenum include Plenum (CUSTOM), In addition to three
standard 4" Collars, ONE 2" (for head)
1.00 Heat Electric Heat 159.00 159.00
1.00 Kit Complete Installation Kit (DELUXE, all bronze parts) 548.00 548.00
1.00 Grill Teak Grill, include aluminum box, and 4" Collar 72.00 72.00
1.00 Rotaire include 2" Diameter Round Closable Grill
10.00 Ducting include 2" Diameter Fire Proof
warranty included 3 Year Limited Extended Warranty

It wasn't a straight forward job.  Needed many decisions on where to mount things and what to give up (storage).  All and all I'm pleased with the finished product.
Jim

[Ken Juul]

using the on line tools available, 16K is about right for our size boat.  The ocean breeze only has a one speed fan, I generally just let it run constantly to keep the air circulating.

[Ekutney]

Thanks everyone for your comments and feedback.  I'm going with a 16K unit but am trying to decide between a flagship and ocean breeze unit, the reason for these making the short list is the Electric heating element.   I'm also trying to decide where to locate the unit, I'd like to keep it centrally located so I'm trying to decide between under the starboard forward settee or the hanging locker aft of the Nav station.   The challenge will be running the duct to the aft cabin.  Any advice from members with current installations would be appreciated.