Refrigeration Upgrades - questions

One of everybodies' favorite topics. Post your technical questions or solutions about your boat's refrigerator here.

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Joined: Sun Jan 10, 2016 4:01 pm

Refrigeration Upgrades - questions

Post by dedgell »

The refrigeration system on our boat, hull 442, has just stopped working effectively. My initial diagnosis is that the temperature control knob (rheostat) has failed. The knob is locked in place in the vicinity of its warmest setting. I’m going to try replacing the rheostat first and see if that fixes the problem.

We spent the past week on the boat icing things down in coolers and talking about upgrades to the refrigeration. Even if the quick fix works
I want to see if we can improve our system. I’ve read through most of the refrigeration forum related to temperature, controls and different configurations. What I have learned is that the refrigeration compartment in our boat differs from the early hulls, and maybe even some of the Mark II boats. First, the box has the improved insulation - when the system is working it stays very cold. Second, there is no bulkhead between the freezer and fridge compartments, and no fan. As such, the space is big and difficult to organize. We use the space inside the cold plate as the “freezer” by stacking frozen food in it. Everything else is essentially refrigerator, with the caveat that items placed in the bottom will freeze if the rheostat is not adjusted just perfect. Again, much room for improvement. I monitor the temp in the refrigeration compartment with an indoor/outdoor thermometer. The system is usually able to keep the refer at 35-37 degrees while also keeping items inside the cold plate frozen. Except this past week, of course.

After that long explanation, I would appreciate any thoughts on the following questions/ideas. Pictures of your upgrades and or part numbers and links are welcome:

1. Has anyone upgraded to digital temperature controls? It would be great to be able to set the unit at one temp and have it adjust itself vs. constantly adjusting a knob.

2. What are the pros and cons of having a separate freezer compartment? I would have to fabricate an insulated bulkhead that I suspect would be similar to the one in the early hulls. It would be nice to have more freezer space.

3. Is a separate compressor and cold plate necessary for a separate freezer compartment? Seems like some early boats had one cold plate and a fan for spillover. How does that set-up work?

4. Has anyone built shelving or other storage solutions to take advantage of the unusual shape of the compartment?

Thanks in advance for any advice about these questions.

Best regards,

David Edgell
Blue Wing, C350 #442
Posts: 10
Joined: Wed Aug 03, 2016 12:52 pm

Re: Refrigeration Upgrades - questions

Post by RFBaker167 »

Hull 167 is old style Freezer Refrigerator. I was surprised to see the set up on newer 350s.
We upgraded to SeaFrost BDxp compressor with 2 large cold plates in freezer. Spill over fan controls refrigerator temp.
We upgraded the compressor to a water cooled model this Spring to improve duty cycle. Initially installed digital controls for both freezer and refrigerator sections.
Sea frost makes larger freezer box that may work better for you. This eliminates the cold plates that we used.
Also, down side of spill over systems is that other cold plates tend to frost up quickly, requiring defrost.
You might be able to run the freezer box and separate cold plate in your system.
I would call SeaFrost for recommendation.
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Captain Kirk
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Re: Refrigeration Upgrades - questions

Post by Captain Kirk »

Hello - this question is for RF Baker.

I notice you mentioned digital controls for both the fridge and the freezer. Do you know which units you installed? Also did they improve the temperature control at all, compared to the mechanical thermostats.

Kirk & Leah McCullough
#031 -Full Batten Main, Rocna 20
Sand Dollar
Point Roberts, WA
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