Disclosure: This post may contain affiliate links. I earn a small commission of product sales to keep this website going.
Using the power of the sun to keep beer cold. I love it.
Update December 2012: Marine 12V refrigeration systems suck a little more power than I thought. Keep reading, and also check out Windpower for how I had to modify my electrical generating systems.
Technautics Cool Blue DC Refrigeration
I just purchased a Technautics Cool Blue 12V DC holding plate system to replace my engine-driven holding plate system.
What’s a holding plate? It’s a metal box filled with a eutectic solution, through which R-134a refrigerant passes in an array of tubing. The refrigerant freezes the solution and it creates a sort of reusable block of ice to keep an icebox cold.
As with everything I do, I noticed some funny looks when people heard I’d be getting rid of my engine-driven system in favor of a 12V DC refrigerator system.
For the most part, I think it’s absolutely ridiculous for somebody who lives on a sailboat to be required to crank up the engine once or twice a day for an hour at a time. Talk about killing the peace and quiet! And wasting fuel! And engine life! My 30-year old engine has 1,150 hours on it and an engine-driven refrigeration system for a liveaboard would put between 500-750 hours on it annually.
What’s the difference between an evaporator plate and a holding plate?
Evaporator plates cycle on and off dozens of times throughout the day and hold a nearly constant temperature. This means cycling at night too when the solar panels aren’t outputting anything.
Holding plates only cycle a couple of times per day and the temperature range is more variable. The Cool Blue has a thermostat to kick the compressor on whenever the holding plate drops below a certain temperature.
Cool Blue Applications
You could also build separate refrigerator & freezer compartments with this system, but I’m just going with the fridge. I might try to keep an ice tray right next to the holding plate to make some ice. What a luxury!
All in all, I think this is the perfect sailboat refrigeration system for someone like me who won’t be using it every single day. I’ll only need to use it when I have perishable food in my stores.
And it’s efficient, so there’s that.
My engine-driven system took up a lot of room. It had a larger compressor, a belt from the engine, a seawater condenser, and a receiver.
This new system is all in one unit, 10″ x 12″ x 9″, and is air-cooled with a fan, meaning I don’t have to suck cooling water from my engine or cut another dreaded hole in my hull. It’ll fit in any well-ventilated space.
I chose to put it in a storage area under my berth. At first, I was worried about the noise from the motor while I was sleeping. But I’m going to try only running this during the day, hopefully when the sun is on my solar panels.
I made a shelf out of plywood and mounted it inside of this storage space. I’m keeping the access door to this space open until I can cut some ventilation slots in it. Then I mounted the new holding plate in my icebox where the old holding plate was.
I ran some 12AWG wiring from my DC breaker panel to the compressor unit and also wired the thermostat inside the icebox to the compressor.
Then I connected the two copper refrigerant tubes to the holding plate, ran them through a hole I cut in my icebox and through my hanging locker and into the compressor under my berth. After that was done I sealed up those holes with some insulation-in-a-can. And that was it!
The most time-consuming part of this whole thing was making the shelf to put it on and running back and forth to the hardware store; the rest of it only took a couple of hours. I did need to charge it since I lost a little R-134a while connecting the tubes.
The system runs great!
Do you have any other thoughts on this system? I’ll follow up on this in a couple months or so to let you know how efficiently it’s keeping my beer cold.