Anyone with Air conditioning/genset??

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Joy Taylor

Oct 18, 2014, 3:23:59 PM10/18/14
Hi all -

I'm in the market for a sturdy catamaran to live aboard and cruise with my family of four. The SF 44 has caught my eye as an incredibly well built, safe, and fast cat. I understand none were made with built in air conditioning. This is not generally a problem, but 3 of the 4 of us have asthma, and when in the midst of an acute attack, Conditioned air is something that can go a long way to helping the person recover.

So my question is, has anyone put ac on their SF 44 or looked into it? If so, I'd love to know what you came up with. I'm not necessarily needing full time, built in ac that runs around the clock, but rather something that can be run for a day or two or at night if someone is struggling and we have to take care of ourselves due to our location.

Any advice would be appreciated.

Thanks so much,


Oct 18, 2014, 9:13:16 PM10/18/14
to St. Francis

Hi Joy,

I have looked into AC for my SF44, but have so far not installed any. The problem is space, both for the
gen set and the AC itself. I currently run dual Honda 2KW gensets that I set on the aft swim platform.
This works well for AC power, as long as there are no rain showers in the vicinity. I use this for a huge
fresh water maker (about 1 gallon / minute) I installed in the port hull, forward of the tub.

There are cabin-top AC units you could run, cold air dumping into the main cabin, but you would need a
storage location while underway. I have made some cut passages that would have dumped them over
the side. Then you also need to figure out how to get power to them.

Diesel engines do not take kindly to being lightly loaded, so I am thinking you would want an aux genset.
These exist, and the most likely installation area would be under the table beside the helm or the rear
lazarette. Then you have the problem of diesel fuel feed and exhaust. (I assume a diesel genset, I would
not install a gasoline unit on my boat, though my Honda gensets are gasoline fed.)

My most rad idea was to buy a cheap "Hier" (Chinese) AC from home depot (maybe $200 to $300). Take
it apart, cutting the refrigerant lines and all. Then take the pieces and install them behind the curve in the
main cabin seating (there is a fair amount of room there). Then ducting the cold air into the cabin, possibly
under the raised flooring for the table, possibly into the starboard sleeping cabin. I haven't figured out
what to do with the exhaust hot air yet. I hate cutting holes in my boat.

One thought that occurs, you could run the heat exchanger lines forward to the locker at the foot of the
mast. You would have to open that locker to let the system exhaust heat every time you wanted cold air,
but it could work for you. I would not leave the heat exchanger exposed to salt water or spray. They would
eat the exchanger alive in one season.

Anyway, re-assemble all AC connections, charge the system with refrigerant, and away you go. I doubt the
entire installation would run more than $500.

Now you have to feed power to the system. I currently have on my boat a battery bank of Chinese AGM
batteries of > 1KW. This might do it, but it could be close. AC is very power hungry.

The alternative is to run your Honda gensets all night, unlikely to make you many friends in crowded
anchorages. All gensets are noisy, some more than others.

These are my thoughts. Sometimes the importance of AC fades. Then, one night in a still anchorage
being eaten alive by no-see-ums revives my interest considerably.

The problems you will face are:
1. where to put it.
2. how to power to it.

Good luck,
Let me know what you decide,
S/V Obeix

PS: You may find that your asthma problems are significantly reduced while cruising, depending on where
you go. Generally, the wind is out of the east, and has been scrubbed by 2K miles or so of ocean.

PPS: You can get a SF 50 with AC, if you can swing the price. The 44 is sexy, the 50 is elegant, and no, I
can't swing the price myself, but I love my 44, AC or not.

> Date: Sat, 18 Oct 2014 12:23:59 -0700
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Clinton Lanier

Oct 18, 2014, 11:09:45 PM10/18/14
to, St. Francis
Hello Obelix.  I agree.  Sand Dollar  SF Hull 31.

Clinton W. Lanier
Attorney at Law
Supreme Court of Florida
Certified Civil Mediator
Admitted to Practice in Florida, Virginia and Montana

Cindy Wallach

Oct 18, 2014, 11:31:50 PM10/18/14
Hi there,
We have 2 reverse cycle air conditioning/ heating units that we installed on our StF44 10 years ago. We can only run them when plugged into the dock at the marina, but space was not a problem in getting it all done. It wasn't cheap, but it got installed in about a week by a professional.

One unit cools the salon, and 2 forward cabins. The other smaller unit cools the aft cabins and galley.

Ducting runs under the settee to the forward cabins and the unit itself sits under the starboard side of the settee. Ducting for the other unit runs through the aft compartment on the swim platform between the two aft cabins. Then through some of the cabinetry to the wall shared by the galley and aft cabin near the sinks. The unit itself sits on the bed platform on the aft port side cabin where we took out the mattress and turned the cabin into a work space. 

I am happy to snap some pics if needed.

Cindy & Doug
s/v Majestic

Steve Walsh

Oct 19, 2014, 9:30:33 AM10/19/14

There has been at least one SF44 with AC/heat installed by Saint Francis. We purchased hull #43 in 2006 and had two 12,000 btu units installed. The port unit was installed in the port aft cabin. We had a cabinet to the left as you entered the cabin and the unit was installed on the lower shelf. This still left plenty of storage in that cabinet. This unit cooled or heated the port hull and one duct into the saloon. The second unit was placed under the saloon seat to starboard and forward. This unit was for the starboard hull with one duct to the saloon. We had a 5K genet installed under the bunk in the aft port cabin. The bunk was positioned port to starboard not for and aft. Fuel for the genset was feed from the port engine compartment. Exhaust was next to the engine exhaust aft. Both units could be run at the same time but one would have to be turned off if the microwave was used. We recently sold Fine Line but if you  have any further questions, let me know.


Sent from my iPad

Dec 29, 2016, 9:36:07 AM12/29/16
to Saint Francis Owners Group
I added two 16,500 BTU Flagship marine a/c's last spring shortly after buying Sand Dollar/Sojourner/SandDallor (2016).  I installed the compressor units under the setee and ran the hoses through the nav table (tricky).  The a/c raw water pump is located in the starboard forward compartment.   I had to install a second 30 amp service to power all the house loads plus a second a/c unit.  The install works great until we have a "90 square" day here in FL.  We used the coach roof sunshade provided by previous owners (not sure whether Clint or Rick) to lower a/c demand when sun was out.

If I were to do it again, I would install a 12k unit aft in each hull and a 12k unit in the salon.

David Reeves

Dec 29, 2016, 12:48:45 PM12/29/16
Congrats on the A/C installation.  I'm not sure if I understand why the hoses go under the nav table if the pump is on the starboard side but...

We've had ZING(43') about 11 years now.  I have only installed a single 16,500 Mermaid system but it works fine NOW because of three enhancements that may also help you.  First, I installed solar panels (4x130watt) on the salon roof as well as (6x158watt) on the cockpit hardtop.  They are about two inches above the salon roof and I believe that this shade helps dramatically.  I think any shade should help.  Second when at the dock we place cut out insulation board (3/4" with aluminum on the outside) under the phifertex window covers on the salon windows.  This is a huge help.  It does make the salon a bit darker but is a good trade off.  Third, we have insulated hatch covers for all hatches which is also helpful to reduce condensation in the colder months.

If you are not going to use your A/C or heat for a while you might want to fresh flush the water lines.

I had a Honda 2000 first, and then replaced it with a single cylinder Kubota running a 200 amp alternator.  Both worked ok but were far from ideal.  We no longer have a generator so our A/C is for dockside.  Other than A/C we are happy with solar only.  I guess we could run the A/C on solar during the day but we don't or at least haven't for much time yet.  I think that both of our generator options would have been much more satisfactory as a backup to our current solar setup. 

I am interested in how others have implemented the A/C and heat thermostat(s) particularly with multiple units as well as what they might want to accomplish.  I have created my own thermostat and am considering having it control variable ducting (for the forward cabins) as well.  I have also developed a custom solar and battery monitor system that helps as well.

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Soggy Paws

Dec 29, 2016, 5:49:06 PM12/29/16
to Saint Francis Owners Group
At the other end of the spectrum, we are cruising full time "out island", and spend most of our time away from docks and marinas.  So we have opted to get just a window aircon unit when we are in port in a hot place.  When we leave to go cruising again, we sell the unit to someone else.  It also makes sure that whatever we are using conforms to the local power system.  Then we're not carrying all that weight around while cruising, and it's not taking up precious space.

The window aircon sits in one half of the sliding door, and the rest of the sliding door is blocked off with a piece of 1/2" plywood and an inch of foam insulation on either side (with the silver side out).  We also have a white cockpit hardtop, with awnings on the sides, and a huge deck awning that covers from the front of the cockpit to the forward edge of the mast (only used in the marina).  With this awning up, we can take out the solid window covers, making the boat less cave-like. :).  

During the day, we close all the interior doors to block off the areas of the boat we aren't using, so the a/c is just cooling the salon.  (There's only 2 of us).  In the hot months, the a/c just barely keeps up in the middle of the day, but it is de-humidifying. And stepping into a space that is even a couple of degrees cooler than the summer temps is a relief. As soon as the sun goes down, we open up the interior doors and turn a couple of A/C fans on to move the cooler air into the bunk spaces. Now (wintertime in the Philippines), we don't bother closing off the doors to the rest of the boat, and our a/c coasts most of the night, when the temps get down to a frigid 70F.

It all depends on your usage scenario for the boat, what makes the most sense to spend your money and your precious space on.

s/v Soggy Paws
Samal Island, Philippines

Keith Lloyd

Jul 10, 2017, 4:24:24 PM7/10/17
to Saint Francis Owners Group
I installed a reverse cycle A/C unit under the salon seat in my SF 44 in 1998. Had to make a hidden duct just under the windows to get A/C air to both front cabins and cut vents just above the beds. I installed a 3.5 kw Fischer Panda under the cockpit table, it fitted quite nicely with a very small extension to the pedestal.  The new owners replaced the gen set with a Westerbeke which was probably a better motor than the Fischer. The A/C worked quite well in the Caribbean though a little noisy at night for people sleeping in the aft cabins (generator noise). I added some sound deadening around the generator which helped. We spent a winter in Annapolis and used the reverse cycle for heating. It worked well until the temperatures sunk below freezing when we had to supplement our heating efforts with 2 electrical heaters. Anyway, bottom line, A/C works fairly well on a SF 44.
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