Join Date: Jan 2013
Location: Marina del Rey, CA
Thanked 2 Times in 2 Posts
Rep Power: 5
Re: Newbe with no experience buys big boat
Right - I tried to make a "cool box" around the compressor-evaporator.
The boat was made in 1977 with two thinly insulated ice boxes. Someone had once put a cold plate and the associated mechanics into the aft icebox. When I bought the boat that unit was just a solid block of rust - would not turn on.
I pulled it all out and replaced it with a new system from the West Marine catalog ($$$$). The ONLY place I could possibly locate it was on a nice flat area on the port side of the engine room. Of course, the engine room is the worst place to locate a compressor-evaporator.
The manufacturer sold a "ventilation kit" consisting of a fan and tubular air ducts, designed to blow cool bilge air on the compressor. But my unit was actually in the ER and inches from the engine itself, so I went one further and build a little "dog house" around the unit, with cool air sucking in from the bilge and blowing out to a mushroom vent located directly overhead. The vent had to be on the afterdeck.
As usual, all this was great in theory, and worked great at the dock, but at sea was another story. The mushroom vent was in a bad spot where people tended to hit it and step on it. Of course, it HAD to be open whenever the reefer was cycling!
In heavy weather seawater would rush past the vent! Unless it was closed tight, water would enter the duct! I had anticipated this and put a U-bend in the duct tube with a small drain hole at the bottom of the U.
The other issue with the reefer was poor insulation. This is the bane with some production boats. I left this part out from the book because the "boatwork" sections were getting too long, but Doug had some experience in doing kitchen counters and he wanted to replace our whole galley countertop, and get rid of the TACKY 1970's fake wood grain plastic crap (imagine how that looked after 30 years).
I went to this on-line company (I forget the name) and purchased all the raw materials to make the reefer box from scratch: fiberglass sheet, VACUUM plate insulation, and a VACUUM insulated door. For your money (and they want a lot of it) you supply them with the exact shape and dimensions of your insulation plates. The plates are something like 1/2 inch thick but because of the vacuum chambers they are equal to 6-8 inches of the best foam insulation.
This was a lot of work but when it was done the whole kit-and-kaboodle (reefer and countertop, glistening white formica) looked and worked great.
Except for the damn vent, the whole system worked great. If anything, it worked too well, freezing stuff we did not want frozen until we learned to dial it way down. Used very little electricity, gave us plenty of real ice, cooled a lot of stuff extremely well. Thanks to the vacuum plates, we could close the vent and open the reefer breaker for 12-24 hours and it would still be cold! Like a thermos bottle, basically. It probably set me back around $4000 total, plus maybe 60 hours of labor, but it worked exceptionally well.