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.
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.
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.
