[C38] spreader droop and AC

Fri Jun 3 17:31:41 EDT 2011

Hello Bill and group,

The back fins on a window air conditioner are the condenser which removes heat from the closed system.  The evaporator is the fins in front which absorb heat into the system.  Since the evaporator absorbs heat, it produces cooling.

The original condenser is an air type which needs to be converted to a water type condenser.  All you essentially do is recover the refrigerant, remove the existing condenser with a tubing cutter, silver solder in the new condenser, and add a refrigerant port to the low pressure side of the system which is the larger pipe going from the evaporator to the compressor. R-Parts of California makes a water cooled condenser which works well and has a fitting for a zinc anode.

 I use 15% silver solder on my conversions which requires an oxy-acetylene torch.  You might get by with lead based acid core solder but I wouldn't try it myself.  Not only is the silver solder much stronger, it's actually much easier to use also.

You will also have to make a drain for the condensate water which will drip from the evaporator.  In a window unit, the fan that cools the condenser will usually have a metal ring around the outside of the blades which will splash the condensate water making the spray hit the condenser and allowing for better cooling.  The dual shaft motor for the fans on the unit will have one fan working a squirrel cage blower in the evaporator section and the other end of the motor will have an output shaft that operates the cooling fan for the condenser.  Take a hacksaw and just cut the back end of the motor shaft off because it is just in the way with a water cooled condenser.  Getting rid of the back fan blade allows the motor to spin faster for the evaporator and also helps keep the unit quieter with one less fan to turn.  The water cooled condenser is fed by a pump in a remote location below the water line so it will be self priming.  I used a Little Giant pump with a magnetic impeller so there was no shaft seals to leak and if the pump impeller did stall, it wouldn't burn up the motor.  Granger is a dealer for the Little Giant brand but there are other good brands also that use a magnet impeller.  The pump I use comes in a cheaper version and a more expensive version for caustic liquids.  I used the cheaper version for many years in salt water with good service.  You can also get the pumps with barb or threaded fittings.  That is a personal call to make and I have built systems with both types.  If you go with the threaded connectors, it is initially more complex but if you ever need to pull the pump for service or replacement, it will be very easy.  We have all had the opportunity to use salty language trying to get hoses off of barbs located in hard to reach locations.

I put a simple 1/2 plastic thru-hull in the bottom of my unit at the lowest place where the condenser fan used to splash the water.

The small refrigerant tube coming from the compressor and going to the condenser is called the "high side" because it is high pressure.  That line is very hot and needs to be cooled by the condenser.  If you can route that small line against the bottom tray so it is wetted by the condensate water, it will add some efficiency to your system.

I know this project is probably more than the average home technician wants to tackle but there are probably many air conditioner techs in your area who would extract the refrigerant , convert, and recharge your system for a reasonable fee if you already have a condenser purchased and ready.  By law, only a technician with approved refrigerant recovery equipment and a Universal license should be doing this procedure anyway but if you saw what I'm trying to describe, you would see it really isn't nuclear science.  Heck, even I can do it!  (legally too!)

I have one of my masterpieces stored in my barn if you want some pics.  Since the original condenser isn't needed or used anymore,  I converted the side air vents of the case for handles to make the unit easier to carry.  

The economy of scale is so much in favor of a window unit price.  You can buy a 12k BTU unit on sale for a fraction of what a marine unit would sell for and also get a remote hand control to boot.  I wanted a good price but more importantly  I didn't want to sacrifice valuable storage space when the foot well under the navigation table was useless space anyway.

I mounted a duplex 120v outlet in the back of the foot well and one side serves the A/C and the other runs the microwave.  You can't see the outlet but you can reach it by feeling under the microwave.  I mounted a dedicated breaker on the electric panel for this outlet.

There is a lot do discuss here, feel free to ask questions.

Tom T.

----- Original Message ----- 
From: William Knowles 
To: tdtron at earthlink.net;Catalina 38 Listserve
Sent: 6/3/2011 1:55:53 PM 
Subject: Re: [C38] spreader droop and AC

Tom what kind of skills do I need to convert the window ac? I can run the pumps etc. but don't know about installing the condenser.

Thanks Bill

On Tue, May 31, 2011 at 5:42 PM, tdtron at earthlink.net <tdtron at earthlink.net> wrote:

When I installed an air conditioner on my 38, I used a standard 12k BTU window unit with remote hand control that I converted to marine use with a water cooled condenser.  I mounted the A/C and a small microwave oven in the wasted space of the navigation table foot well.

I mounted the cooling water pump under the quarter berth between the fuel tank and hull.  I tee 'd off of the engine thru-hull and strainer.  I put a water discharge thru-hull just a few inches above the boot stripe so I could see the water discharging from the cockpit for a quick visual check for flow.

Modifying a window air conditioner is very easy.  R-Parts in California will sell you a ready made heat exchanger condenser if you don't want to make your own.  Any air conditioning technician should be able to make the conversion for you if needed.  I wanted to make use of the wasted space under the navigation table and the air conditioning and microwave did that.  I also kept the board under the microwave to hold can foods for pantry storage.

I sold my 38 but I have made several of these A/C conversions in the past and all worked well.  With the conversion like I made, you lose no storage space because the foot well on the 38 is essentially wasted space anyway.  

Tom Troncalli

----- Original Message ----- 
From: Max Soto 
To: Catalina 38 Listserve
Sent: 5/31/2011 3:00:20 PM 
Subject: Re: [C38] spreader droop and AC

Bill and Marci,  
I have a 16000 BTU Marine Air installed forward of the starboard settee, It took the space of the two upper drawers and some space on the hanging locker.   The discharge thru hull is located behind the ac unit on the same locker and the intake thru hull,  500gph March pump and the  strainer are located under starboard settee..

I wouln't recommend a larger unit... For the heat here in Costa Rica, during the day it works great, but at night, when the themp drops a few degrees, the unit keeps cycling a lot...
Will send pics soon.

Hope this helps.

Regards,

Max

2011/5/31 Marci Brown <mb at seafor.us>

We had a new, portable (and properly vented) 12,000 BTU AC on our boat when
we lived in Virginia. It didn't cut it! With the lack of boat insulation, I
don't believe anything is going to work short of a permanent 18,000 BTU
heating/AC system.

Marci J. Brown
PO Box 520549, Winthrop, MA 02152 USA
Ph: 757-502-7422 | Email: mb at seafor.us

-----Original Message-----
From: William Knowles [mailto:whk1965 at gmail.com]
Sent: Tuesday, May 31, 2011 12:48 PM
To: listserve at catalina38.org
Subject: [C38] spreader droop and AC

Hello all. After a great weekend of sailing I have two questions. First
whenever we sail in wind over about 15 to 20 and the windward shrouds get a
little slack our spreaders droop about 5 degrees I think it may be because
our shrouds are a bit to loose, but would like some input.
Also we took our freestanding ac unit off the boat, it worked ok but took up
a lot of space and was always fighting against itself with the exhaust hose.
We have used window unit into the cockpit on other boats, but very hard to
get in and out. Would like ideas on the porta cool and permanent mount
reverse cycle units. As always thanks in advance for your help. By the way
it was in the nineties on the Chesapeake yesterday.

Bill Flying Goose   324

_______________________________________________
Listserve mailing list
Listserve at catalina38.org
http://catalina38.org/mailman/listinfo/listserve_catalina38.org

-- 
Max Soto
C38 #198 ESTANCIA
Puntarenas, Costa Rica

_______________________________________________
Listserve mailing list
Listserve at catalina38.org
http://catalina38.org/mailman/listinfo/listserve_catalina38.org

-- 
W H Knowles
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://catalina38.org/pipermail/listserve_catalina38.org/attachments/20110603/6f0bad14/attachment-0001.htm>