Fridge Fans (Internal & External)
Anyone who uses an absorption refrigerator, like our old Dometic NDR1292, knows that the hotter the weather, the less efficient these fridges operate. Basically, it gets increasingly difficult to get hard ice cream as the outside temperature rises.
Adding a fan (inside or outside a fridge) is a relatively inexpensive method of improving the performance of an absorption refrigerator.
INSIDE A FRIDGE
The purpose of adding a fan inside a refrigerator is to improve efficiency by moving the cool air around.
I tried a 12V internal fan that I bought on eBay. This 2-fan unit draws its power from the light inside the fridge. Don’t worry, it’s connected in such as way that the fan stays on when the door closes.
This virtually silent dual-fan moves the air around pretty well.
Another type of internal fan just uses a battery to power its fan. These units run for a long time, but must be constantly monitored. Camping World sells them as well as other vendors.
However, while both of these internal fans worked ok, I had heard that adding an external fan to cool the refrigerator itself might work a lot better.
OUTSIDE A FRIDGE
The goal of an external fan is to cool the gas absorption unit of the refrigerator itself.
On the back of an absorption refrigerator — the business side — a cooling unit is attached to the back of the fridge. The cooling unit works by heating a tank of ammonia which turns from a gas to a liquid. This process cools the refrigerator, but heat is generated which is supposed to be removed by the convection air flow in the back of the fridge.
However, in hot weather it becomes more and more difficult for convection alone to remove this heat.
So to improve air flow a fan can be placed either at the back of the cooling unit or at the roof vent. I added two thermally-controlled fans from www.coolerguys.com inside the roof vent. These fans turn on when the temperature reaches 88 degrees F.
Here are photos from my installation . . .