More Wisdom from Strictly Sail Chicago. Today it’s all about refrigeration design by Bob Williams of SALT (Sea Air Land Technologies).
First a little about Bob:
“Bob Williams has been involved with the boat building industry since 1976, working directly with the builders as well as commissioning and delivering yachts for customers throughout North and South America. Through his company SALT (Sea Air Land Technologies) innovative products were developed for the marine industry including energy management monitors and regulators, DC ice makers and fully sustainable energy management systems for yachts and off-grid homes. Bob has provided on site system design and installation training for boat builders in the US, China, Singapore, South America and Europe.”
As you can see Bob has just a little knowledge about boat systems and energy management. 😎
I’ve actually had the opportunity to hear Bob speak on various topics in the past at previous Strictly Sail Shows and at Cruiser’s University in Annapolis.
At Cruiser’s U Bob covered wind and solar technology for sailing and you can read my recap here. I also attended his offshore Energy Management seminar, but did not post a recap on that topic, at least not yet.
Refrigeration in offshore sailing is a hot topic for sailors as I see questions and advice seeking on various forums on the topic. Since refrigeration is the biggest draw on energy on a boat, it’s no wonder. Plus let’s face it, we want something other than canned foods to eat while sailing.
Here are some main features in marine refrigeration that Bob suggested we consider:
- A refrigerator with no drain hole.
- This is because the drain draws cold air out of the refrigerator and therefore makes it less efficient.
- Want to counteract the mess at the bottom of the box? Then try these refrigerator coasters (along with other moisture adverse products) that my friend Jess tried out on her sailboat last year with good success.
- A full refrigerator is more efficient and draws less amps.
- A long rectangular box is less efficient.
- To remedy this, insert insulated partitions within the box to improve efficiency. (Apparently you have to make these yourself as I could not find any, except spill over dividers, that were already designed.)
- Avoid metal lined boxes.
- Top loading is more efficient than front loading.
- Drawer style is a good compromise.
- Double door seals are the best.
The front loading which of course are sexier and easier to get things out of, are less efficient because they let warm air in when you open them. I read somewhere that the way to help negate this is to hang plastic strips in the front to help contain the cold air and prevent the warm air from entering. You’ve probably seen these on commercial walk-in coolers and freezers where they were added for the same reason.
If you go with a drawer style refrigeration system, you can design it with an offset condenser to move the heat away from the drawer. They also come as water-cooled.
Marine Refrigerator Maintenance:
- Schedule at the minimum of every two years, to tighten all of the screws.
- Keep a spare refrigeration drier (keeps excess moisture out of your compressor).
The latest technology in refrigeration is Keel Cooling. The advantages of Keel Cooling are:
- Uses water to cool.
- Fewer moving parts, so less to break.
- Smaller compressor is needed for this system.
- More efficient
- No pump is required
- Quieter running.
The draw back of Keel Cooling systems is that you will have to haul out in order to install and it can only be used while the boat is in the water.
If you live on your boat when it is hauled out as many cruisers do, then you will need to add an air-heat exchanger to the compressor to run the system so you can keep things cold on board while hauled out.
The keel cooled refrigeration is very appealing to me and is definitely a system I will consider for my sailboat.
What type of system do you have and what do you like/hate about it?
I’d love to know.
See you on the water,
Sail Away Girl