Modify Car A/C for Use on Sailboat - Thoughts?

[Fishman_Tx]

I have all the parts (new and used) to take a car a/c system and attept to modify it for use on our Bristol 34. Would need a custom bracket and hoses, already got an extra groove on the pulley, but where to put the condensor? Possibly use 6" dc computer fans cuz putting a fan/shroud on the engine is out of the question. Guess I COULD make a waterjacket for it....


B34 w/ Westerbeke engine aft mounted under cockpit sole and behind companionway steps.

[clockwork orange]

Trouble is it will only work with the engine running and you have a sailboat.
Steve.

[roverhi]

Ah Beeville, went through advanced flight training there in the '68. I know it gets a bit sticky in south Texas but have tried natural ways to cool the boat. First would be an awning to shade the deck of the boat. We spent a summer in Tahiti and didn't really have a problem with heat. We had an awning from the mast to the stern that kept most of the deck, and thus the boat, cool. Very comfortable to set under the awning while it was frying outside. Had a pup tent awning for the foredeck that provided shade and also acted as a wind scoop to force air through the boat. That wouldn't work to get air into the boat in a slip but there are other windscoops that aren't directionally challenged. We didn't have fans down below. Really only wished we had them at around dinnertime when stove heat, accumulated heat energy, and the calm between the sea and land breezes made the cabin uncomfortable. A few fans spaced around the cabin would go a long to allaying the heat. Personally, can't see running the engine constantly to get air conditioning. If you can't live without it at the dock, get one of those portable boat units and use it tied to shore power. If at all possible, stay away from marinas. Boats are way cooler anchored out where they can lay to the wind and naturally aircondition themselves.

Aloha
Peter O.

[barnakiel]

Exactly!

- shade (if made in good acrylics will last years),
- open up the boat (add wind-catchers over hatches),
- look for a drafty spot,

Even within one marina there can be the windy and the calm spots, get a windy one for the summer.

In extremis - if the shade is already on, then you may place an old bedsheet on the cabintop/sidedecks and wet it (a couple of times - it will dry fast). As the water evaporates the deck/roof will cool down a lot - you will be surprised how much. It may look odd, but it works.

[s/v Jedi]

Yes guys, that's all true, even in the tropics.... until the sky goes black and rain comes down like there's no tomorrow, hatches go closed and you have to cook dinner. Believe me, that is no fun.

But when you have A/C, after closing all the hatches etc. you can fire up the genset and have that jet stream of cool air while doing the cooking. Very nice for sure.

With that car A/C you would fire up the engine instead. Good idea when you have no genset and much like engine mounted compressor for fridge/freezer. I bet you can use 1 compressor for both fridge and A/C (not at the same time for both though).

cheers,
Nick.

[Fishman_Tx]

Nick gets it

Ok, sorry guys, not trying to be a snot here. This is something that IS GOING to happen, not a question of "should I". I'm well aware of the ramifications and cuz I AM the ultimate cheapskate, I'm NOT dropping a grand on a cruisair(or any expensive 12v system either) that's what the "window-unit" on a board in the companionway is for. Actually this is for use while under way as a cabin cool-down in the evening(or whenever). I'll be running the engine to charge batteries and cool the reefer anyway so no since in being uncomfortable while I'm at it . And what about those doldrums and days becalmed waiting on the wind? If I'm motoring, I'm chillin'.

Ok back to the question (stay with me guys), what to do about cooling the condensor? I'll reiterate my previous statements:

"I have all the parts (new and used) to take a car a/c system and attempt to modify it for use on our Bristol 34. Would need a custom bracket and hoses, already got an extra groove on the pulley, but where to put the condensor? Possibly use 6" dc computer fans cuz putting a fan/shroud on the engine is out of the question. Guess I COULD make a waterjacket for it....
B34 w/ Westerbeke engine aft mounted under cockpit sole and behind companionway steps." There is lots of room aft and starboard of the engine under the sole.

Thx!

[Fishman_Tx]

Also, a small 12v "squirrel cage" and a piece of flex duct could be attached to an aft dorade with a "butterfly valve" or a spring loaded flapper(keeps out any seawater), drawing the warm air out thus ventilating the engine compartment while the engine is running. This will also assist in cooling the condensor by cooling the engine compartment.

[s/v Jedi]

I would just get a water cooled condenser. The question is where to get the water from.... Maybe just the easy but safe way out with an extra pump.

cheers,
Nick.

[Fishman_Tx]

Well....
She's going on the hard in Sept for the refit and the main seacock & thruhull (engine) has to be replaced. Would one "upsize" and "T" off the new seacock or use 2 new points of failure, uh, I mean thruhulls?

[Caribsailors]

Here are the best sources of parts I've found. This is how I supplement the kitty while cruising. I like the condenser from seafrost the best, just put it in to your engine pick up after the strainer, & don't forget the high pressure cutout in the control circuit.

Depending on how FRUGAL and handy you are, you can make your own water cooled condenser. Just make sure the flows are opposed.

hxxp://www.rparts.com/
hxxp://www.seafrost.com/edr12parts.htm
hxxp://www.seafrost.com/engine%20drive%20air.htm

[Intentional Drifter]

How about something like a keel-cooler, or a water cooler running through your water tank (course, you'd need a pump). You might be able to get the parts from one of the used marine parts stores. Something like the Frigoboat condensers.

Believe me, I appreciate what you're doing -- we spent much of last July/August on the ICW, much of it motoring, and it would have been very nice to cool ourselves off, below!

ID

[Intentional Drifter]

Question: Would the unit enough BTU's to actually make a difference? Lots more volume in a Bristol 34 than even a big car. It would be a shame to go through all that trouble and then only see a 3 to 5 degree difference.

ID

[speakeasy]

Originally Posted by roverhi

Ah Beeville, went through advanced flight training there in the '68. I know it gets a bit sticky in south Texas but have tried natural ways to cool the boat. First would be an awning to shade the deck of the boat. We spent a summer in Tahiti and didn't really have a problem with heat. We had an awning from the mast to the stern that kept most of the deck, and thus the boat, cool. Very comfortable to set under the awning while it was frying outside. Had a pup tent awning for the foredeck that provided shade and also acted as a wind scoop to force air through the boat. That wouldn't work to get air into the boat in a slip but there are other windscoops that aren't directionally challenged. We didn't have fans down below. Really only wished we had them at around dinnertime when stove heat, accumulated heat energy, and the calm between the sea and land breezes made the cabin uncomfortable. A few fans spaced around the cabin would go a long to allaying the heat. Personally, can't see running the engine constantly to get air conditioning. If you can't live without it at the dock, get one of those portable boat units and use it tied to shore power. If at all possible, stay away from marinas. Boats are way cooler anchored out where they can lay to the wind and naturally aircondition themselves.

Aloha
Peter O.

Sound advice. Just read a new CF generator thread from Louisiana of a sailor breaking in a 20KW and having a hard time finding enough load to satisfy the manual. Most threads here talk of the balancing act of having enough generating capacity to make water or run refridgeration without turning on the iron genny. I think you've hit on the most pleasing of solutions, ie., leave the swamp for the cool breezes.

btw, mate, I did my advanced at Kingsville in '66. Went from there to A-6's and from there to Chu Lai in '68. The Flying was amazing but the war was sad and without honor. I'm still trying to get back to the thrill, but not at 500 kts. 5 or 8 will do. Sounds like you've been at it a while now. Cheers, Jon

[S/V Illusion]

Originally Posted by Intentional Drifter

Question: Would the unit enough BTU's to actually make a difference? Lots more volume in a Bristol 34 than even a big car. It would be a shame to go through all that trouble and then only see a 3 to 5 degree difference.

ID

I was thinking the same thing - there is a huge difference between cooling a car interior and that of a boat. Additionally, by the time you got through playing McGuiver trying to build this into something functional, you'd have spent the equivalent in money and time as if you just went out and bought the purpose-built A/C the boat requires.
I am not implying improvisation is a bad thing but more often than not it is based on a false economy that usually ends up costing more

[Fishman_Tx]

In actuallity, none of the above system is going to run without the engine running. The system will be tied in just like the standard automotive system. None of it will be tied to house batteries and will ONLY work when the engine is running. I have 2 Optima Bluetop SC34 start batteries on the engine, so there will be no problems in that area. The alternator will be replaced with a high output unit so that the extra load can be handled. All else fails, I'll put in 2 alternators. 1 for the house and 1 just for the ac, tho I don't think that will be necessary. Remember this is an engine driven compressor. Actually, it's the system out of a Chevy S10 (R134).
As for McGuiver, I already have all the parts. The only $$$ spent will be on the extended freon lines and the engine block mounting bracket. Couple hundred bucks at worst(lines and freon), I can make the bracket myself, and I might decide to buy the compartment ventilator prefab(used on PB's with gasoline inboards).

Re: water-cooled
This is something I would REALLY like to avoid doing, I would prefer to keep it simple and inexpensive vis-a-vi, air cooled. I figure 6 - 6" or 8" 12v muffin fans would do the trick IF I can properly ventilate the compartment.

Re: Cabin volume
Well, won't know til ya try! Can always try to use a larger fan/evaporator combo. Much isn't expected from this rig. Sometimes just drying the air out and bringing the temp down a few degrees can make the difference between stifling and bearable. After years spent in various desert locations in my younger days, I'll direct your attention to the functional characteristics of the ubiquitous "Swamp Cooler".