Boat Air Conditioning

I like to have an air conditioned boat. My first installation was on my 18' Seaswirl. I used a 5,000 BTU window unit (<$100), some dryer hose and a homemade collection box to catch and direct the cold air.

 I mounted this air conditioner in an aluminum frame, but on a subsequent installation I just made corner supports for the base and secured the unit with a stout bungee cord.

The collection 'box' is PVC pipe with just enough cut away to cover the exit vent on the air conditioner. It's held in place by a strap with a snap.

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I ran the cold air into the cuddy cabin via dryer hose terminated by a single adjustable vent.

The two speed blower in the air conditioner was OK at night but wouldn't push enough volume mid day in the heat, so I put a bilge blower in the dryer hose (seen in the first picture between the bends in the hose). It was a little noisy but a small price to pay for the comfort.

I powered the unit with a Honda EU1000i generator mounted on the stern.

A cover for the front of the generator allowed us to run it underway even in salt water and rain.

A "T" and 2 way valve in the boat's fuel line after the primer bulb allowed me to fill the generator by switching the fuel flow to the generator line and pumping the primer bulb to put gas in the generator. It took about 100 squeezes to fill the empty Honda tank. Later I installed an electric fuel pump in the generator fill hose.

In addition to the air conditioner, the generator was also used to power a host of other devices, albeit one at a time.

I later upgraded the window unit to a 6,000 and made the air box out of doorskin, incorporating the bilge blower in the box.

This air box just hung on the window unit.

Then, for those days when we wanted to be cool underway, I would disconnect the dryer hose from the inside vent and route the cold air to a couple RV sanitation hoses which we could hang around our necks to blow cold air up our chins, or route the cold air inside a windbreaker.

Update 6/27/2015

The above is complicated and there seem to be other options -- like the coolers that blow air over ice, like for instance Icybreeze. There are also articles on DIY models for around $50. These units are spot coolers, not air conditioners. They will let you blow some cool air on yourself for a limited period of time. Here's some math:

A pound of ice is worth 144 BTU's.
A cooler can hold 30 lbs of ice.
Thirty lbs of ice is good for 4,320 BTU's.
Let's say you're thinking about cooling a small cuddy for overnight comfort. Considering an outside temperature of 85° I'm guessing that it takes a about 3000BTU's/hr to keep me comfortable in the small cuddy. This is based on my 5,000 BTU air conditioner running continuously (but without recirculating) to maintain ~70°. I'm thinking then that you'd you'd need to melt a little over 20 lbs of ice that first hour and you'd get 1 1/2 hrs out of 30 lbs of ice. But it's not likely that you could melt the entire 30 lbs in an hour and a half anyway. Want to go for 7 hours? That's nearing 150 lbs of ice for 3,000 BTU/hr. You could settle for less, but then you'd only be pretending to be comfortable.

Bottom line, you can blow cold air from a fan driven cooler full of ice but it's not likely that you'll find that approach workable for anything but temporary spot cooling.

Tides

Halls Harbor - in

Halls Harbor - out

Maitland - in

Maitland - out

Hyder - in

Hyder - out

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Low Tech Spotlight

Manual spotlight like you might see hanging off the side of a police car. I replaced the non-functioning one that came with the boat.

When I pulled the fasteners from the old mounting pad, I noticed that there were 3 different sizes.

Three of the screws were stainless and the other one was zinc plated. I don't know about you, but I am totally unable to mix fasteners within a set. I won't even mix phillips with slot...it's just something I can't do.

Transfer Switch

Big Duck came with a forward shore power inlet.

I put a second shore power inlet in at the stern primarily because it was close to the generator and simplified the wire run.

I needed a survey to get insurance. The survey said I needed a transfer switch so the unused shore power inlet wasn't hot.

I made one out of 2 30 amp double pole switches and a dial that makes it impossible to have them both 'on' at the same time.

Van Trouble

I put Big Duck on the front hitch to push her into her new Boat Port. The view with the trailer in front of the van is much better and the ability to maneuver is outstanding. What I didn't consider tho, is with around 700 pounds on that front hitch ball, the back end was bound to get a little light. It wasn't really all that bad - the back end broke loose several times but I was able to back up and get a little momentum to get 'over the hump'. Worst case I would have put the equalizer hitch on the front and used the arms to transfer some of that tongue weight to the rear wheels. I did learn tho, from slight skidmarks in the grass, that my limited slip rear end appears to be working.

During the final positioning of the boat in it's new home, the van motor started loping, then running rough, then the check engine light came on. I pulled the codes - 2195 and 2197; they told me both banks were running lean.

Ford Truck Fanatics suggested the codes indicated a vacuum leak.

I couldn't tell much from under the hood, even after I removed the air cleaner.

I hate pulling the engine cover on the inside of the van but I had to do it.

 

Now I had a better view, and quickly noticed an open port on the intake (black nipple).

I searched for a hose hanging loose, but none was to be found, so I capped the open port. My idle came back, but now I noticed I had no heater or a/c control - it was always on defrost. Now I knew there had to be a hose somewhere that needed to back on that port, but none was in sight. I thought maybe the hose had come completely off and was lying on the road somewhere?

After a good night's sleep. I got out my flashlight and started rummaging around the open engine. There just weren't any unconnected black rubber vacuum hoses hanging around even though a vacuum diagram on the internet said there should be one on that open port.

I then started touching/tugging on everything close to the open port. I found a loose pair of wires which when freed from the intake manifold, terminated 90° into what appeared to be a spark plug boot - but there was no electrical connectors in the boot. Am I an idiot or what? This was the missing vacuum line(s). I was looking for a rubber hose, these were two small plastic lines encased in a split loom jacket...the red one exposed for a short section. It's shown here reattached. You can bet there'll be a zip tie on that boot before I put things back together.

Now to get that engine cover back in place...uuug.

Another thing I noticed while poking around, which threw me off, was this exposed 1/2 of a port that looks like something is missing:

Apparently it's not used, but it is kind of strange.

Duck Digs

Big Duck fits nicely in her new 24 x 31 x 12h Boat Port...~$2,500. Sides to arrive soon.

The Boat Port is long enough to get a second car in behind the van.

Bow Eye Turnbuckle

Had this turnbuckle lying around. It's always nice to rely on something other than the strap.

Ductless Duct

The question of how to get the cold air from the rooftop a/c forward to the helm area is for the moment at rest.

I had considered a second a/c unit, maybe a split, but wasn't ready to make that commitment. Then we put the R2D2 unit (portable a/c with window vent) forward but it took up too much room and wasn't very satisfying. I also entertained making a duct of some kind thru the head with a small fan to encourage the cold air forward, but that meant cutting holes and I wasn't yet ready for that.

We had used a high velocity squirrel cage fan to just blow cold air forward with good success, even in 100+° temps, so I made the installation temporarily permanent by cutting a slice out of a piece of pvc pipe and using what was left as a mount for the fan. The a/c blows cold air out at ceiling level and the squirrel cage being higher not only sucks in more cold air, but also now has a direct shot to the helm.

We eventually found a less cumbersome way to send cold air forward.