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Locating and venting a portable A/C unit

Posted: Jun 30th, '09, 22:09
by STeveZ
A previous thread (and my first mate's encouragement) got me thinking about a portable A/C unit for use dockside. The hatch units are pretty self contained but they're also pretty big and awkward to haul around when underway. I'm kind of drawn to a small, cheap unit like this one.

Image

http://www.portableairshop.com/PAC8000S ... nditioners

The review say that it doesn't produce a lot of water, and a drip into the bilge wouldn't be a big deal anyway. For location I'm thinking the footwell area of the v-birth or possibly under the dinette table.

My question (finally) is venting this thing. Any ideas for a slick venting arrangement? I think a panel placed in an open window would look like hell. I'm wondering about simply venting into the engine compartment (creates a route for fumes/CO to enter the cabin) or simply running a vent under the aft dinette seat and through the aft cabin bulkhead. This route seems pretty straightforward though I'm always hesitant to drill large holes without giving it some thought first.

Posted: Jun 30th, '09, 22:28
by Tony Meola
Steve
They really do not cool very well and on a hot day I don't think it will do the job. So before you drill any holes, stick the vent out the window and give it a try. If it works then figure out a good venting system.

Remember, any holes also let in cold are in the cooler seasons.

Posted: Jun 30th, '09, 22:53
by In Memory Walter K
If your dinette windows are sliders, open up one fully. Make a cardboard template of the open space. Use the template to cut a piece of plywood, Azek, Coosaboard etc and cut a hole into the center of it to fit the exhaust/vent ring that usually comes with the unit. They are usually the quick disconnect type. When you need it, open the slider, fit your panel into it's place. Slide your slider back to hold it tight. Snap on the vent hose into the fitting on the panel and you're set to go. If you paint it white it won't be visually intrusive and hell. if you want to, a local plexiglass place could cut one out for you and it will look like your window. Being flat, it's easy storage. The water run-off hoses are small and discharge a minimal amount. Bilge or bucket. Some even have a pan you could empty with an automatic shut-off when it is full

Posted: Jul 1st, '09, 20:32
by Wingnut
Steve,

I love the idea and I think Walter is right on the mark with his suggestion to make a panel that fits in the side window as a vent.

How many BTU's is the unit you are looking at? If you do this let us know how it works! I thought about a similar set up for my 28 and don't want to lose the space of a permanently installed unit.

JD

Posted: Jul 1st, '09, 22:30
by STeveZ
Wingnut wrote:I think Walter is right on the mark with his suggestion to make a panel that fits in the side window as a vent. How many BTU's is the unit you are looking at?
I'm warming up to the idea of a side window vent. The unit I'm looking at is 8000 BTU. Click on the link above for more info, including a video.

It would fit under the dinette (where I have an AC outlet) and wouldn't expose that much unsightly vent hose in the short run up to the slider. We would most likely use it only at night for sleeping. If I decide to give it a try I'll definitely report back.

Posted: Jul 1st, '09, 22:58
by CaptPatrick
Remember that hot air rises and cold air sinks. Placing the unit down low will really limit the efficiency... Might cool your feet, but it'll be a while before it gets to your sweaty brow.

Posted: Jul 1st, '09, 23:10
by STeveZ
I guess the counter forward of the dinette makes some sense. It would be out in view but you could vent directly to the slider behind.

Posted: Jul 2nd, '09, 07:35
by offshore31
Steve

Definitly let us know how it works out. Might be an inexpensive way to get occaisional a/c.

thanks
Joe

Posted: Jul 2nd, '09, 09:31
by Rawleigh
Steve: Do you have gunnel scoops? Maybe you could vent into them.

Posted: Jul 2nd, '09, 10:36
by STeveZ
Rawleigh wrote:Steve: Do you have gunnel scoops? Maybe you could vent into them.
That thought had occurred to me. I'm hesitant to do anything that involves the engine compartment or could impact engine air flow. Better safe than sorry, ain't broke don't fix it, etc. etc.

Posted: Jul 2nd, '09, 10:47
by CaptPatrick
Ever run your auto air conditioning with the re-circulation bypass off? Allowing the system to draw an amount of outside air in?

Ain't nowhere near as cool as a closed recirculated system.... I wouldn't connect the unit to anything that would allow it to draw in outside air. If it's necessary to vent the unit because of heat generation, vent it to the cabin bilge.

Posted: Jul 2nd, '09, 19:16
by Preston Burrows
Steve:

Also take a look at RV websites' 115V airconditioning units and consider...............Coleman type,roof [hatch] mounted...................most need a 14"x14" cutout if I remember correctly and you can install it in either the cabin door hatch or the bow hatch,both are ~20"x20".................for what they cost and ease of install may be perfect for you..........drawbacks would be in being 'permanently' mounted and in not being able to open the hatches.................you'd just have to duck under into the cabin even more than usual if installed at the doorway hatch........I figured I could install anything between 8,000 or 12,000 BTU's capacity/size wise there that would fit under the bench seat overhead without mods to it.........I would take the cabin hatch off and build one instead from 3/4" glassed/painted or gelcoated plywood to mount the unit on/in.........I only haven't yet as I spend little time inside the cabin except to retrieve beers from the fridge...................

Posted: Jul 3rd, '09, 16:44
by Bruce
The heat comming off the cond coil is the same as whats comming off your outside ac unit. While not quite the volume, it gets real warm.

Outside venting is the only option to keep the cond coil temp down which makes the unit as efficient as designed.

Most of those units if you read the fine print say low water output cause of use in very low humidity areas.

Considering most of the US during the time AC is needed is med to high humidity, much water will be made and need to be drained. I would not use a bilge unless you are on the boat. Other wise direct overboard thru a sink drain is best.

An AC is Just a dehumidifier is reverse and we all know how much water they develop.

Posted: Jul 4th, '09, 23:26
by scot
Steve,

There are some marinas down here that consider a home window unit hanging of the side of the boat a real neat idea. I had a slip mate in Port Arthur that had a huge honkin window unit bolted on his 20ft blow boat. He stayed in the boat for IKE...they found him intact, seriously shaken up, about 200 yards from his slip...high and dry, trapped in a pile of boats, go figure.

Just to be clear, I don't advocate this type behavior, or this type AC system.

Could you vent to outside air with an OEM chromed brass engine ventilation cowl? That may look right at home on the boat assuming you can find a good spot for it.

A/C

Posted: Jul 6th, '09, 13:27
by Bill G.
Please keep me in the loop as well for my 28...............TXS, Bill G.