Emergency, Jack-Rigged A/C

D

drjohn71a

New member
Ok, be forewarned - this is not a pretty sight. I don't know how to post photos in the writing parts, but on Tom-a-Hawk's photo file, I put the first photo of a quick A/C test.

It was 90 degrees and humid at Grand Lake, OK, and I hauled one of the portable GE A/C units I use in the upstairs bedrooms in my old farmhouse down to the boat.

At 33 inches high, the 7,000 Btu unit just fit tightly against the foredeck roof and the forebunk floor. It would also fit in front of the front dinette seat, under the table, on the aft port cabinet top or over the stove area. I was looking for a spot where I could leave it during the summer without having to load and unload it from the boat as we took on passengers, etc..

This unit burns 9 amps running and needs a slow blow 15 amp fuse to startup. The hot air exhaust fits well in the TomCat forward port, and I ran a drip hose back to the shower sump for the test. The West Marine calculator says a TomCat needs about 13,000 Btu's to stay cool on a100 degree day while out in the sun, but this little unit did pretty good while under cover at the slip and got downright cold in the nighttime.

They have 9,000 and 12,000 Btu units out that are shorter, so that may be an option in the future. I really don't need A/C much while out underway, so I may just use the one I already have for now. I'm guessing a genset and that 12,000 Btu unit would work pretty well, though.

I'm working on a removeable, sturdier installation setup so, don't let Dr. Bob of Thataway see this until a more seaworthy setup is in place!

Question - what would be the best way to route that condensate drip hose? I see that the under bunk hull spaces don't appear to drain aft into the hull where the bilges could pump it overboard.

Should I drill holes and run a plastic pipe back to drain out of the aft cabin wall into the cockpit? Should I drill a hole somewhere to drain it into the bilge where it would get to the bilge pump? ....Or, would that cause moisture problems in the bilge?


Any advice would be appreciated.

John
 
Ok, so now where do you sleep?

I would put in a separate self contained shower sump under the foreward seat in the dinette. There is a space there, as big as the water tank space on the stb side.

We sized the AC so that it would cool at night, and be tolerable during the day. We are told that there is a 13,500 Polar which will run on the Honda EU 2000. I just wonder about moving this air conditioning unit around, getting around it when it is in "place", as well as the plumbing (both heat extraction and condensate), when the roof RV is so much easier. If you want to take the roof air off during the winter, then put a regular RV vent on the opening, or one of the Vantastic Fans, etc.

How much bigger is the 12,000 BTU self contained AC unit? Weight and size? The other issue is will it bang the interior up when you are running and will it obstruct places where you will want to get into?

Yes, there is no connection between the storage in the hulls under the foreward bunk--and I would not put a tube there, because at rest, you have a chance of this being a low point (where the "V" of the hull is). Also on the trailer, this will probably be a low point.
 
Dr John-

If you find a permanent or regular place inside the boat, why not just add a through-hull for the condensate above the waterline and let gravity drain it overboard w/o any pump involvemenmt? (Maybe I'm missing part of the picture here, though.)

Another thought: Some of the portable A/C units get rid of the condensate water by evaporating it with the hot exhaust air. Could you add a metal aor plastic box in the hot air exhaust system and drain the water into it to evaporate and taken away with the hot air?

If you really don't need A/C out underway, do you anchor during the heat of the day and need it then?

If not, then I'd think you could simply mount the A/C unit on a frame built for it under the marina cover and route the cold air into a cabin window with a flexible tube, thus eliminating the whole issue of how to place and connect it on board the boat.

Do you have 120-v AC available at the marina? Might be able to eliminate the generator, too.

Trying to think inside, outside, and maybe even underneath the box.....

Joe.
 
thanks all for the info...

I guess that Joe's suggestion of a thru-hull above the water line would be best, but I am a bit scared to go drilling out to the water side. I was thinking a 1/2 inch pvc waterline could be routed from the forward bunk back to the cockpit with a tee near the back cabinet in addition to the forward opening. That way I could move the unit up on the cabinet if I needed.

The newer 9,000 and 12,000 Btu units are actually smaller than this unit. I've had this one for almost 5 years.

The condensate drain has to be within 6 inches of bottom of the unit in order to drain while the hot air exhaust is about 16 inches above the bottom, so that evaporative setup is out.

For some reason, I don't seem to feel too hot while out on the water. We usually have pretty good winds around here. If things get too bad, I just take a quick dip.

I do not yet have the genset. Like you advise, that Honda 2000 ought to do the trick.

The slip has TWO, 30 amp circuits per boat.... so power there is not a problem.

One major aim for my using this type of unit is to have A/C while using the boat as a camper on the way to the Gulf or long trips. The marine A/C units with water cooling could not be operated on the trailer. There is the new plate style, non-water cooled unit on the market now, but it costs about $3,000.

Right now, I'm thinking of just getting the newer, smaller, 12,000 Btu unit and doing a "semi-permanent installation" by building a removable "fence" around the base, bolted to the wooden bunk surface. Other locations are possible, but I don't want to drill a bunch of holes in the countertop this early.

Sleeping room? Gosh, that bunk is cavernous. I like to sit up and read alot in bed, so resting my back against the A/C unit seems kind of nice to me. Also, it is not hard at all to slide the A/C unit out to the forward dinette seat foot area, leaving the entire bunk clear.

I really think the easily reversible nature of these units, along with their ability to work without water, make them a good alternative A/C.\

Thanks for all your input!

John
 
OK, Joe.... condensate problem solved... I went to Pep Boys at lunch and got one of their 12,000 Btu units ($479). It has the condensate evaporation built in and only needs a 3" diameter exhaust hose - no condensate hose.

On top of that, the new 12,000 Btu unit uses fewer running amps (8.5) than the 5 year old GE 7,000 Btu unit (9.0 amps). The new "larger" unit is shorter by 3 inches (30" X 15" X 16"), so would fit better in more areas than the old "smaller" unit (33"). It weighs 65 pounds - a bit less than the old 7,000 Btu unit and much less than a comparable RV rooftop A/C.

I'll try to rig a mounting system and place it in the boat sometime in the next few weeks. Lots of competing things.... son grads from KU this weekend.

John
 
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