This is a big site. I’ve been through some discussions, but I still have confusion/questions. I really haven’t found what I am looking for. I joined this site because I am search of answers. You guys seem really nice and friendly. I like that. I hope you can lend some assistance.

To start, I am not a Refrigeration Engineer. I’m actually a sailboat owner. 6 years ago, I had a problem with my refrigerator on my boat. I pulled into a marina and the Service Manager suggested that I replace the unit with something entirely different. For a unit that had AT MOST 100 hours on it, I could not put my head around spending the money for another system. That started my quest to learn refrigeration.

I read as much as a could on the Internet, ordered boat refrigeration books, talked to specialists, etc. I now have a good understanding of the components and how a refrigeration system works. To make a long story short, I found the problem with the installation of the LO side connection. This resulted in corrosion on the connection that resulted in a pinhole in the evaporator bin. This has been fixed.

The problem that I have now is that I want to get away from the aluminum evaporator bin and convert to stainless holding plates. This has energy conservation benefits for my application. The problem that I am having is in the application of the products. For example, if I use a seawater condenser and an air-cooled condenser in series in the Bahamas, then move my boat to Canada, I may have to turn off the seawater condenser and possibly partially block the air cooled condenser (so I am told). Why does this make sense? If I move my boat to cooler climates, then why would I restrict the cooling capacity of my condensing units? I don’t get that. Wouldn’t it be more efficient?

If I think back to Gary’s tutorial, the best outcome is to have the condensing unit condense the vapor to liquid right at the output of the condenser. That makes sense to me. It seems most efficient. If I add in changing environmental conditions, then the saturation point changes. Right? I could be condensing at some point before or after or not fully condensing at all??

If my thinking about this is correct, then the question come down to what parameters can we control? Should I set a PID loop around the evaporator that regulates the temperature differential that increases and decreased the condensers to make the system most efficient for example? But condensing temperature is going to change with pressure right? So, the set points will change. Is that right?

I’m pretty much convinced that I will need to design and build and custom system to handle the varying conditions that a boat may go through. I just don’t know how to approach it. Any information (links) on how to approach this would be most appreciated. Please unconfuse me.

THANKS!
Mark