water cooled Air Con

[bazobeleza]

I've just been reading over on the Liveaboard Section about a chap that's fitted a domestic AC unit to his yacht, the internally mounted part of the 'split' looked Ok however the external heat exchanger part, a tin box with a fan mounted in it stuck before the mast looked a bit Heath Robinson, but it got me thinking...

Would it be possible to use the internal wall mounted part of the 'split' as normal but mate it up to some form of water cooled heat exchanger with a small electric pump? that way I wouldn't need to cut holes in my beloved boat or have a rusty tin can on the coach roof?

 

[Heckler]

I've just been reading over on the Liveaboard Section about a chap that's fitted a domestic AC unit to his yacht, the internally mounted part of the 'split' looked Ok however the external heat exchanger part, a tin box with a fan mounted in it stuck before the mast looked a bit Heath Robinson, but it got me thinking...

Would it be possible to use the internal wall mounted part of the 'split' as normal but mate it up to some form of water cooled heat exchanger with a small electric pump? that way I wouldn't need to cut holes in my beloved boat or have a rusty tin can on the coach roof?

Yes, but you would have to be a smarty pants like me to do it!
Stu

 

[sarabande]

look up "reverse cycle" air conditioning and heating units. Had one for years. They have an efficiency ratio of about 3:1 using the sea or lake water as the heat/cold source.

 

[DownWest]

I think they are quite common in the US. Look in West Marine for info. At least you would be spared the noise of the big fan on the outer unit.
A

 

[trapezeartist]

look up "reverse cycle" air conditioning and heating units. Had one for years. They have an efficiency ratio of about 3:1 using the sea or lake water as the heat/cold source.

I'd never thought of that before, but it would make a fantastic heating unit. When we lived in Spain we had reversible aircon that worked beautifully as a heater in winter, because the outside temperature never fell below 8 deg. In England, the outside coil would frost up in no time. Transferring the concept to a boat, the outside coil would be in water at 8 or 10 degrees (or 283 degrees Kelvin, to get a better handle on where the heat is coming from) and the quantity of water available would be "infinite" so no problems of icing. I like it!

 

[daveyw]

I've thought about ripping a car ac system out of a scappy, replacing the condenser bit with a pipe outside the hull in the curve of the keel joint. Not sure if it would work and it's a lot of effort and hassle if it didn't!

 

[rogerthebodger]

I have done it.

I got mine from a local company called Airco who supply the McQuay unit made in Malaysia.

I fitted the indoor fan units under some of my bunks and built ducting into the interior to take the cooled air up to the highest level possible. The compressor or outside unit is the type fitted to separate shops inside big shopping centers with the cooling water piped to an outside cooling tower.

The cooling water in my system and I have 3 separate systems is pumped around and cooled by passing the fresh water through a hollow skeg where the fresh water is cooled by the sea water around the skeg.

I went for 3 smaller units to keep the power requirement down as the shore power at most of the marinas in SA is quite small and also to power it from my internal generator is required. I try not to use the inbuilt generator too much.

Since I fitted mine the compressor unit has been made smaller so easier to fit.

There is also available a chilled water unit that does not need the refrigerant to pass from the compressor unit to the inside unit so is easer to install with just insulated plastic water pipes and not copper refrigerant pipes.

I do have an installation manual available that I could E-Mail to any one interested.

My particular one also has heating by reverse cycle so can also take heat from the sea but in Durban and the east coast of Africa this is not really needed.

 

[rob2]

A condensor can be made from a common heat exchanger, such as a truck oil cooler. the design is similar to that used in indirectly cooled engines with a stack of pipes running through a large tube. The more difficult part is calculating and finding the right size and a pump with the right flow rate for the seawater flow.

Rob.