Electric Cooling Fans - Dometic RM 4200 60l 3 way fridge

I always put mine at the top and blow the air out the top vent.

You need to seal the sides of the cabinet from the heated air which is at the back.
Foam or similar will do so the gap around the fridge is isolated from the heat.
That means less working heat is applied to the sides and top.

THEN.
Fit a fan to draw air into the rear of the enclosure near the bottom and one at the top to exit the hot air. That way YOU are creating a desired flow of convection and it will remove a lot of heat from the condenser, "the finned bit". Then the fridge will operate at it's full ability for the ambient temp it is in.

Just one fan doesn't provide a positive change of air and at the top it can be sucking hot air but also not positively drawing it through/past the fins on the condenser.
Computer fans run off a plug pack when 240v is available or house battery when away from 240v gives two options to select from and the same cooling ability.

Hi all,
Here is a blow by blow guide to installing the fans(s).

I run two at the top, with the sides and back of the fridge baffled and/or closed in.

They run off the van battery and I have an off/on switch behind the fridge to shut them off when the outside temp is not going to affect the fridges efficiency.



bill

Why is it so.

The fridge is running on gas at the moment and I have a room fan blowing air up the back of the unit. Current outside temp is 27 and the temp inside the fridge is 15, which is far too hot for meat, milk etc if I was away somewhere.

BUT the temp inside the little freezer section is -10. So why is it so??

If the freezer is -10 and the main fridge section is 15, I do not understand why it can be as I understand that the freezer and fridge run off the same cooling circuit like a normal fridge but because the main fridge is larger in volume it is warmer than the freezer but -10 in the freezer and 15 in the main fridge are at opposite extremes.

Any ideas

Thanks

Thanks for all the input.

I put two 12cm fans on the back of the top grill and one in front of the cooling fins inside the fridge.

Difference was quite noticeable. You can feel the heat and the fan closest to the heat tube is hottest.

The fan inside the fridge also circulates the air quite well as well.

Also - the coils at the back were covered in red dust I guess limiting heat transfer - while it is not possible to clean them all up without pulling the fridge out I cleaned where I could from the top opening and that seems to have made a difference as well.

Cheers

Garry

I have just spent 4 days away with the new cooling arrangement for the fridge. Prior to leaving it was on 240v and was working perfectly. I wasn't prepared to risk using it for perishable food so loaded it up as my drinks fridge. I also put a dozen milk ice, ice creams in the freezer section as it has always worked well.

For the 10 hour drive it ran on 12v and also worked fine maintaining about 4 degrees until late afternoon when outside temp started to rise and the fridge temp went to 8 but cooled down as soon as the sun went down.

In site on gas - no issues with the ice creams remaining frozen and solid and the temp of the fridge rising and lowering with the outside temp (up to 27). The fans both internal and external seemed to work well.

Coming back home was more problematic and verified my choice not to put perishable food in the fridge. On the way back running on 12v the outside temp rose to 33 and very windy and the fridge did not cope as well with temps getting up to 13 (though the freezer was still working fine with the remaining 3 ice creams still frozen and solid.

So the two cooling fans in the back and the recirc fan inside work well but the temp cutoff for the fridge to work properly is about 30 degrees - above that it is no good so really could not be used in summer.

It was a great exercise but I think I need to look for a small upright compressor fridge but there do not seem to be any of a similar size to what I have.

That then brings in the other issue of batteries and power generation - we had full sun but in a shaded camp area and my 120w panels only managed to generate about 8Ah a day and the 55l compressor fridge used 5ah during the day and about 2.5ah at night so barely breaking even. An overcast day or so would make a major difference. (The old cheapie ebay fridge only pulls about 3amps when running).

But that is another topic for another day.

Thanks for all the input.

Cheers

Garry