Non-Conformative Air Conditioning

[Bob4203]

Hey Gents,

Did someone say, "free standing ac unit"?
I can tell you from experience that they have lots of pros and cons. The pros first: They are free standing, tall, narrow and will fit standing up in the quarter berth, or nested to the side of the companionway ladder without getting in the way. The condensation will evaporate in the exhaust so no dripping on the floor. They are now available up to 11,000 btus (maybe even higher, but I have yet to see one). When running they will handily cool off a C30 cabin in the evening for a great nights sleep on a hot summers night. They are not very expensive. You can take them home after the season.

The cons: The heat is exhausted through a flimsy accordian 4-5 inch diameter plastic hose. I beleive its about 5-6 feet stretched out. The amount of heat given off is INCREDIBLE and will heat up the area behind the unit rapidly therefore liimiting your cooling area.

HOW TO REMEDY THAT?

We use a 9,000 btu Heier unit and stand it on the quarter birth with the exhaust hose going out the cockpit port window (we have a 1988 Mark II model). We llearned very quickly that the heat in the quarter birth was getting intense. So we went to Home Depot bought some blue inch thick foam insulating wrap and proceeded to cover the hose with the foam secured by reflective duck tape. We had to stretch out the hose and wrap the whole thing save a few inches on either side. The wrap worked perfectly and the heat was tunneled out the vent. No radial heat felt of the hose. The difference was amazing!

So, the standing units are a not too expensive dockside fix to hot summer nights and better sleeping. Do not expect them to keep you cool inside on a hot day. Use a short a distance as possible on the vent hose from unit to exhaust area. Your limited anyways by the length of the hose. For those with the Mark II or cockpit/quater birth port hole, that porthole is the best location. For those who do not have that porthole, thes eunits come with a adjustable house window insert that allows for the hose to be attached. This can be placed between the campanionway hatch boards but you will have to ad a few pieces of wood here and there to fill in. I would make a template of the lower companionway hatchboard (largest) cut out a piece of plywood and permentaly attach that window exhaust piece to it after you cut out the whole in the wood for the exhaust. Perfect!

Bob
1988 Mark II C30
Georgia

 

[shipwreck66]

Bob, I tried one of those last summer and immediately noted the extreme heat they put off. Also, it takes a big portable unit to give the same cooling capacity that a simple 5000 btu window unit gives. Power is the big limitation in what we are looking for, and ultimately my goal is cooling away from the dock off a big battery bank. I'm actually going to try breaking down a window unit into components and mounting them in the back of the galley with the vent angling out into the cockpit.

 

[Merlin Clark]

Mybuddy beat me to it. Here is an ice-powered condensing air conditioner that uses ice as a cold source. It will dry the air, as it blows the air through a dry chilled heat exchanger rather than a wet evaporative membrane. No mold due to excessive humidity.

See what you can do with an ice chest, a plastic tote, an automotove heater core, a fan, some hose and a bilge pump?

Phil,
Any idea of what could be used as a low volume 12v inline pump? I'm thinking about making a closed system.
I made one of the fan blowing over store ice cubes, PVC vent pipes and stuck it in my daughters Wrangler to see what it would do. I need to go and check it now, was doing pretty well about 20 minutes ago.
Thanks,

 

[philwsailz]

Phil,
Any idea of what could be used as a low volume 12v inline pump? I'm thinking about making a closed system.
I made one of the fan blowing over store ice cubes, PVC vent pipes and stuck it in my daughters Wrangler to see what it would do. I need to go and check it now, was doing pretty well about 20 minutes ago.
Thanks,

Bait tank recirculation pump is one that comes to mind. I also know that the wakeboarding crowd uses lots of pumps for filling and draining ballast tanks. There are plenty of 12v pumps out there that would work for a closed system, I have just not researched recently.

 

[Merlin Clark]

Thanks Phil.
I ran that non heat exchanger system for 2.5 hours on a 10lb bag of partially melted ice and still had about 15% left.
I think 2 bags of fresh ice and a few of those blue ice things could last the night. I'd have to use a more efficient fan than the cheap clamp on I had for this.

 

[shipwreck66]

Mine is back in the water, as of yesterday, temp is still 105, gotta start working on my heat exchanger AC thingamagig.

 

[Tori Taylor]

We have a freestanding portable AC unit on a 26 foot boat. It is located on the berth on the port side of the boat by the cabin entry. The exhaust is a five inch vent hose and a neat little round hole thru the fiberglass into the cockpit area eliminates the extra heat. The exhaust hose is then directed over the side into the water. When not in use it can be stored in the back berth or our land storage unit and the hole has a neat round cover which looks identical to those instruments near it like the depthfinder. It is 11000 BTUs and on a 100 degree day it keeps the cabin at 79 to 80 and the v berth at about 86. At night it is very comfortable sometimes too cold. Perfect for on the dock with shore power. Does take up some space but doesn't need to be moved to sail or anything just stowed during winter. Total cost $300 only one hole in the fiberglass and not unattractive. Yes only works on shore power and does produce heat but vented properly works great. We clean the filter weekly and empty the water every two weeks.

 

[Merlin Clark]

We have a freestanding portable AC unit on a 26 foot boat. It is located on the berth on the port side of the boat by the cabin entry. The exhaust is a five inch vent hose and a neat little round hole thru the fiberglass into the cockpit area eliminates the extra heat. The exhaust hose is then directed over the side into the water. When not in use it can be stored in the back berth or our land storage unit and the hole has a neat round cover which looks identical to those instruments near it like the depthfinder. It is 11000 BTUs and on a 100 degree day it keeps the cabin at 79 to 80 and the v berth at about 86. At night it is very comfortable sometimes too cold. Perfect for on the dock with shore power. Does take up some space but doesn't need to be moved to sail or anything just stowed during winter. Total cost $300 only one hole in the fiberglass and not unattractive. Yes only works on shore power and does produce heat but vented properly works great. We clean the filter weekly and empty the water every two weeks.

Cool Tori!
Sounds like you guys have a good solution to staying aboard dockside.
I'm exploring the options for being able to be comfortable away from the dock and without the use of a generator.
Where do you guys sail? Jax? I think a trip up (South) the St Johns and back would be very interesting.

 

[Tori Taylor]

So far we just sail here on Lake Monroe but this fall we plan to sail/motor up to Jacksonville

 

[Merlin Clark]

Sounds like a good trip. Lot's of wild life. Have fun!

 

[Joe Diver]

Mine is back in the water, as of yesterday, temp is still 105, gotta start working on my heat exchanger AC thingamagig.

I've resigned myself to waiting for October.

 

[shipwreck66]

Stand by Joe, I may have a have to solid mount a window unit behind the galley by this weekend, if my boat doesn't try to become a submarine again. I am going to modify the front of a Frigidaire 5000btu unit to fit, I think.

 

[RobertLangdirect]

On my boat at least, it's a space issue...

I've also considered under the companionway.

I've thought about installing one of those very small window units...

.....relocate the controls and hardwire it in to the shore power A/C system. . .

On my Pearson P31, GOOD TRADE, I used a dremel tool to cut a 16x12 whole through the back wall under the companion way and installed a cheap home unit. As the P31 is wired for AC, a breakout box was all the extension that I needed to run power. Did nothing as far as controls, just used the unit out of the box.

I did set it on a cheap 99 cent aluminum cookie sheet and I let cit drip onto the floor of the engine compartment, and then into the bilge. Oh, and a bit of scrap luan to box cin the unit as it will not extend more than an inch or so beyond the back of cthe compartment as I have control units and the forward edge of the cockpit there.

A small fan to blow air up into the v berth is all we need to keep the whole boat cool.

I´ll try to remember to get a picture and post it here.

 

[Joe Diver]

I wanna come out and see that if/when you do it...

 

[shipwreck66]

Got all the shroud off unit today, looks perfect. the cooling coils are only 9 inches tall w/ the fan behind. The fan has styrofoam around it forcing the air up where the vents are. I see no reason why the air can't be ducted out the right side into a 4" duct and run back into the salon.

 

[philwsailz]

Got all the shroud off unit today, looks perfect. the cooling coils are only 9 inches tall w/ the fan behind. The fan has styrofoam around it forcing the air up where the vents are. I see no reason why the air can't be ducted out the right side into a 4" duct and run back into the salon.

I pulled a much larger window unit down from the shelf the other day and began looking at how to re-engineer it without disconnetcing hot side fom cold side. With a smaller unit, I see that it could be rather easy...

Got back out to the shop the other night for a little while, as it had cooled off. Apparently the silicone sealant I used to glue the heater core to the baffle had been heat-affected. It did not dry, but rather is a crumbly gooey kind of mess. Gotta clean it all off and try again with a fresh batch. two steps forward, one step back.

I still think ice-powered on the hook is going to work and work well, but I need some cool temps in the shop to acutally get some work done on mine... OH, I saw something that will improve ice life in the recent GOOD OLD BOAT magazine. Some guy has a mold to freeze ice blocks to conform to the bottom of his ice box. Similar or same done with our ice - powered AC units will provide slower melt rate...

 

[shipwreck66]

The cooling coils are surrounded by styrofoam, with a section on top cut out which forces the air into the ducts via the fan. I ductaped a piece of foam over that openning, cut a 3.5" sq on the right side into the foam, attached a piece of flexible duct, and SURPRISE!, it actually works and wonderful cold air is now coming out 3 ft away. The idea is to modify the casing to fit in behind the galley, rear will be in port storage, run the duct under the storage unit above galley wall and into the salon along the port side. For now I will have to vent by raising the storage lid, but plan to add a powered blower to vent the hot air. Of course, with 105 deg it may be Oct before I finish any of this.