The Fridge Fan

Not long after we bought Chestnut I read in Canal Boat that a neat trick was to put a hole in the floor behind the fridge and fit a fan on it. This, apparently, has two advantages:

  1. The fan drags cold damp air from the bilges under the floor, that means warm air is sucked in to replace it from the boat cabin. Circulating air around the bilges is a very good thing, apparently.
  2. Blowing the cold damp air up the back of the fridge past its radiator, increases the efficiency of the fridge quite a bit.

As everyone knows, a fridge works by sucking the heat out of its inside and getting rid of it by heating up the radiator at the back. How quickly the radiator can get rid of this heat depends on the air temperature around it, the colder and damper the better.

This must be common knowledge as the Fridge itself, a Shoreline RT141, has wiring to supply an external 12 volt fan – it even turns on and off as the fridge does.

It is the grey wire attached to the fridge controller at terminal F that powers the fan. The grey wire makes a third joint in the 3-way connector block. You can just see the fan wires attached to the red and grey connectors.

But where does one get a 12 volt fan of about 100mm square that would fit over a hole in the floor big enough to extract a decent air supply from the bilges?

It turns out – any Computer shop. And as I’ve spent the last 40 years working with computers I have a bag full of suitable fans.

So, it turns out all that was needed was some wires and some woodwork. Here you can see the slot the fridge fits into, along with its 10A socket, and the fan sitting above the hole in the floor that sucks in air from the bilges and blows it straight up the back of the fridge. The fridge itself now sits on the two small wooden pedestals that are enough to lift it about 20mm off the floor so that it clears the fan.

ADDED October 2023.

Last year the Fridge finally packed up and we replaced it. See the blog “the new fridge”, all was well except the new fridge, same model as the old one, no longer fits on the plinth.

Turns out Shoreline have changed the feet. The new feet are smaller.

So I needed to move each of the two plinths visible above about 5mm inwards, so that the new feet would stay each side of the guides you can see. This worked but the fridge would still not clear the 25mm fan as the feet are 10mm smaller. So I have cut into the plywood around the fan and sunk it about 15mm. The fridge now fits on the plinth with the Fan connected and running.