Refrigeration Education

[Jim Rushing]

Just starting to look at the effort of installing refrigeration in my 35.5. Trying to understand the differences between holding plates and evaporators.What works best and what uses the most energy? Currently looking at a Isotherm SP model. Advantage is no new holes in the hull and low power consumption. Anybody tried one of their units?

 

[Rick Moore]

Refridgeration

Hi Jim..You might consider a holding plate to be like a battery, in that it will store cold, like a battery stores energy. The difference in efficiency is more related to the type of compressor and cooling that is used. In the same box, with the same compressor system, each will use approximately the same amount of power to reach the same temperature. The main advantage of a holding plate is that the compressor is not cycling on and off every few minutes like an evaporator. I started with an evaporator and found the compressor to be on for 5 minutes, and off for 5 minutes, 24 hours a day. When I switched the same system to a holding plate, the compressor would run for 40-45 minutes and stay off for an hour and a half. The only thing I added was water cooling which helped freeze the plate much faster. Less switching on and off means less stress on the compressor, and longer service life. Holding plates are usually better, but also take up more space in your box.Hope this helps.

 

[Bob G.]

Isotherm

I installed the holding plate unit. The installation of the system was very simlpe. All lines are pre-charged. I installed the through hull while I had the boat out for the bottom painting. The hardest part was beefing up the insulation of the ice box. It was stressed by Great Water that it must be well insulated to get the most out of a holding plate system. I cut out the cabinet inside the stove opening and went in through the inside of the cabinet next to the sink to rip out the old insulation. I was redoing the countertop and trim at this time also so it was good timing considering the carpentry work needed to get to the box. My ice box is about 5 cu. ft. and this system has worked great. The temp. in the box stays at 38 to 42 F. They say you can build a small compartment next to the holding plate for freezing. I am thinking about giving it a try. You can get info from the dist. at www.great-water.com they wer very helpful to me in answering my questions when I was shopping. Good luck.