TROPICAL YACHT REFRIGERATION
- Ideally there should be 5 to 6 inches of closed cell polyeurethane foam on all sides of the box and on the bottom. Lids can get away with 3 inches. Check around the box casing, open the galley draws, perhaps you can squeeze a couple more inches here and there. Add as much foam as possible on engine room bulkheads. A reflective outer surface will help to reduce radiant heat leaking into the box. Closing curtains or hatches to stop the sun beating on the counter top will help no end.
- There should be good seals on the lids and front openings are a no-no for energy efficient offshore cruisers, so seal them up with silicon and don’t use them if there is a top entrance too. An easy way to improve the seal on the top is to lay a large place mat or rubber type sheeting on the counter top that can be rolled out of the way to open the box lids. This stops the moisture in humid air from reaching the evaporator and prematurely frosting it up.
- Defrost regularly, ice on the plate is an insulator and stops the heat being efficiently removed from the box. NEVER use a sharp implement to remove ice. Transfer all food stuff to a cooler and switch off the compressor. Pour warm water on the plate and allow the ice build up to fall off. Thoroughly clean and dry the area and then after the plate is at ambient temperature switch the unit back on.
- Extra unused box space should be filled with gallon or liter containers of fresh water, (or cases of sodas or beer) this acts as a temperature ballast. As produce and items are removed from the box replace the space with more water bottles or drinks or towels or cushions/pillows double wrapped in plastic bags. This means every time you open the box you don’t suck in as much air at ambient temperature as you have reduced the actual amount of free air space inside.
- Make sure the box drains are covered or fitted with a plug.
- Hang a white piece of sheeting or canvas over the rail, immediately outboard of the box to reduce the radiant heat gain from the hull when the sun beats upon it.
- When you go to provision, tote a collapsable or solid cooler with you so that pre cooled meat,produce and drinks are put into the box cold.
- A small low amp computer cooling fan mounted on top of a p.v.c. tube can be used to circulate air in the box and maintain more even temperatures. On most Danfoss compressors the fan is connected in parallel with the condenser cooling fan, but be sure the total load of both fans does not exceed 0.5 amps at 12 volts, otherwise the black contol box will be damaged. If the fans do exceed the rated load then a relay will need to be fitted. On Mexicolder units this relay is already fitted and so it is a simple job to piggy back spade connectors onto the fan terminals of the relay that sits on the double fan condenser shroud.