Honey we fixed the fridge

Ok, we have had a lot of people on the boat this season. One of my friends that stayed is a refrigeration engineer. Baden has worked in the design of air conditioning and refrigeration projects for years. We were discussing how poor the standard isotherm boat fridge is. How the insulation is inadequate and it ices up in no time. It also has a huge temperature variation between the front and the back.
The fix was obvious. Put a tiny fan in the fridge that comes on when the fridge ones on.
The other was the inadequate cooling inside the fridge cabinet.
The cabinet cooling was easily fixed. We used a large hole saw and put a hole into the sliding glass door cavity. Then we blocked most of the vent into the saloon, so that the only way the air could travel was through the exit fan. Baden quite rightly pointed out that if there was a fan on one half of a vent, and the other half was open, air would just circulate around the vent and wouldn’t draw any air from near the fridge compressor. Now with a hole in the wall inside the sliding door cavity, we have really good cross ventilation in the cabinet. The fridge runs so much better…

Not satisfied with this, Baden tackled the ice inside the fridge and uneven cooling. We had a tiny computer fan. All we had to do was drill one small hole for the wires… one small hole….
Well we managed to completely middle the one pipe in the wall. Gas immediately spewed from the drill hole. It was time for a beer. No… it was time for some rum.
After a few rums, we decided to find the pipe and examine the damage. Out with the angle grinder and we removed a section of the metal case. A bit of excavation through all sorts of foam and cardboard and we found the pipe. It was the main pipe, and we didn’t nick it, we middled it.
We googled a new fridge… and had some more rum after seeing the price.
Ok… perhaps we can fix this… we carefully applied JBweld to the pipe, then put a fibreglass re enforcement wrap around the pipe. The following day we filled the system with compressed air… it actually held air. The big question was had we blocked the pipe? With 30 years experience in the refrigeration industry, Baden gave our repair a 5% chance of success…. Now he tells me…
Well, we got a guy in who laughed at our repair, but regassed the fridge. There is only 160 grams of gas in the whole fridge system. Well the fix held and the pipe wasn’t blocked. The fridge lives again. And I’m almost forgiven for killing the fridge.
We encapsulated the pipe in epoxy resin and put expanding foam all over the fridge for better insulation. The final thing we did was to put a flexible air duct hose from the fridge compressor fan to the cabinet outlet fan.

The final result has been a huge improvement. The internal fan has stopped the fridge from icing up, and the internal temperature in much more even throughout the fridge. The installation and cross ventilation has drastically increased the efficiency and it doesn’t work nearly as hard.
You are welcome to give it a try… just don’t hit the pipe!

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And make careful measurements of the door cavity for the cross ventilation hole.

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Yeah, to JB Weld! It’s amazing how well it works. One of my alternator bracket bolts on the engine stripped out, so I filled it with JB Weld and re-tapped it. Many thousands of hours later, it’s holding fine.

Mike, do you have pictures of the fan and where you installed them?


It’s a tiny fan, but that’s all you need. It’s on the back of the wine rack. The easy way is to unscrew the wine rack, install the fan on the back of the wine rack, the feed the wires.

The fridge computer… yes the fridge has a computer.
Monitors the amp drawn by the fan. The maximum is 1 amp. If the combined fans draw more than 1 amp, then the fridge won’t run. It’s a protection . The compressor is a danfoss compressor.

In hind sight, I’d just feed the wire through the hole where the thermostat is.

I wouldn’t recommend drilling a hole…

I would recommend putting a 50mm plus hole through the boat wall into the slot where the sliding doors go. If you position the hole level with the compressor and just a bit forward, you will get much better ventilation. Obviously measured it 6 times… the fridge cabinet is quite a longer than the door slot.

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