Tuesday, May 23, 2017

Air Conditioner Install Version II

We spent last summer at Snead Island Boat Works padding the cruising kitty. It was the hottest summer in Florida since record keeping began, and we were without an onboard air conditioner since we had removed it prior to leaving for full-time cruising in 2013 for some extra closet space. We installed a window unit and per the request of several readers we detailed the installation. That installation did the trick for the summer, keeping Worker Man cool in the evenings after a hard day in the heat, but the trailer-parkish nature of the installation always bothered me. The duct work was unwieldy, and the silver wrapper disintegrated so quickly in the sun that it allowed rain to soak the pink insulation and run red dye all over the deck. Toward the end of the summer we were getting black mold in the duct work from all the rain-soaked insulation. This year we needed a better design.

After thinking it over and researching the R-value of various foam board insulation, I came up with a better idea. With the help of Worker Man we installed the new duct work last Monday so I thought I'd pass along a few photos for anyone else wanting to install an external air conditioning unit.

We started out the same as last year, by placing the window unit on the side deck just outside the head port on a rubber pad to reduce vibration. We cut two pieces of 2" silver-backed foam insulation board that went from the sides of the air conditioner to the cabin top.

Then we made the bottom of the duct out of 3/4" foam board, running from the top of the intake portion of the air conditioner grill, across to the cabin top, making a right angle, aft to mid-deck, 45° over to the main salon hatch.

We then built sides for that duct work out of 2" foam and square box sides for the hatch (we removed the hatch cover). All of this was duct taped together with Gorilla tape. Last, we cut a top to go over the whole thing, again out of 2". I used a roll of white Gorilla tape to tape over the whole top. The stuff is great at protecting from the sun and rain. This gave us a much lower profile duct, much more appealing visually, and much more efficient at an average R-value of 8. It also came in at total project dollars of $35 vs nearly $100 last year.

And we had lots of extra help this year!

Project notes:

If I could have found it in stock locally, I would have used Foamular board. It would have been much less messy to cut.

If I hadn't run out of white Gorilla tape, I would probably have continued to cover the whole duct work on the sides. This would make it even less aggravating visually.


Robert Sapp said...

Can you use the boat with all this in place (go sailing)?

Deb said...

@Robert - no we can't go sailing but it has nothing to do with the air setup and much more to do with the fact that we have seven people's worth of junk strewn around the boat, a hyperactive toddler and a sick pregnant female. We never went sailing last year when we were on the dock until the fall. Tim is always dead tired when he comes home and he just wants to crash under the air outlet. It's just too much to go out when you're working 40 hours in the Florida heat. Hope to see you guys sometime when you're passing through!

Keith Wolfe said...

The A/C duct looks great! The white gorilla tape is a nice touch and helps it blend into the deck.

Question: It looks like you do not have the cold air return hooked up, correct? On a small space like a sailboat I guess it doesn't matter.

Another option is described for a small Schucker 23 trawler that looked so good I didn't even notice it when the wife and I visited last summer. I believe the author gives sources for materials too. http://janice142.com/Articles/AirConditioning.html

Deb said...

@Keith - yes, we do have the cold air return ducted. It's really hard to see in the photos, but the a/c unit is sitting right in front of the port to the head. the side foam frame work goes from the a/c unit over to the cabin top (about 5-6"), then we put a small piece of foam between the top of the cold air return grill and the bottom of the cold air output. This boxes in the cold air return so that it feeds out the head port directly into the a/c unit. I removed the filter from the front of the a/c and I installed a piece of washable a/c filter in place of the head port screen so I can access it easily. We wash it about every 5 days or so. The piece of 3/4" foam that makes up that divider between the grills is then the floor of the long duct going to the salon hatch.

The Burnhams said...

"Ghetto" as all get-out, but looks like it'd work fine. No one (probably) reads boating blogs for political commentary, but I thoroughly enjoy your perspective on the current state of affairs in the good ol' U.S. of A. these daze...
Keep up the good work (in the yard and online..) we appreciate your efforts.

The Burnhams said...

Oh, I forgot to ask: How many ROLLS of duct tape did this install take? And how do you remove the MESS it leaves on your gelcoat after removal?
We use the simpler "box on companionway slide" but is IS in the way (and heavy/difficult to slide shut in our "pop-up" down-pours...) No ducting required with this technique, but doubtless less efficient as there is some mixing of cold and return air. We're not cavalier about climate change, but how else can you rationalize $2.00/ft./day dockage if you're uncomfortable?!?

Richard Clark said...

These points are kinda helpful in decor manner. Otherwise, I don't usually go for ductless air conditioning.
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