Cooling fan for 3way caravan fridge

Get a couple of 12V 120mm computer fans and install them at the bottom to blow up across the fridge. Some put switches or even temperature controlled switches on them.

Can be run off the 12v supply to the fridge

is it hard to cool when on gas and 240V, or just 12v?

If the latter then you need to do 4 things and it will be fine.

1)Use MINIMUM 6 B&S wiring in your vehicle.
2)Replace the fridge wiring in your van with minimum of 6B&S wiring.
3)Take ou the fridge and surround the fridge with home insulation
4)Add the fan you suggest.

If it is not ok on gas and 240v then start with item 3

Hi Bob, here you go... http://www.dreampod.net/boroma/fridgefan.html

I have 2 x 120mm Arctic fans inside the top vent sucking the hot air over the condenser fins and out. IMO this provides better control than having fans pushing air from the bottom.

Cheers
Greg

This is a link to what Dometic says is the optimal installation Guide.

Dometic Optimal Installation Guide.

Save your money and time on a fan to force air past the condenser. Hot air rises anyway - - if installed correctly why would you need a fan to make the hot air rise??. Besides that the condenser needs to run at a certain temperature to evaporate the coolant. Use of fans can reduce that temperature so the condenser can never work.
The critical factor is as stated. It must be installed correctly. the major fault in this area is having a gap bigger than 25 mm from condenser to caravan wall. The air just runs past and not through the fins. The other issue is that is must be totally sealed from the inside. i.e. as stated insulation round the sides and top to ensure the fridge cannot become trapped in a 'balloon' of hot air.
If all that does not work bear in mind these 3 way fridges are useless and any temp above 32'C anyway!
Andrew (who replaced a well known 3 way with a compressor because nothing could make it work!)

try this

https://www.facebook.com/photo.php?fbid=10204984773487719&set=p.10204984773487719&type=3&theater

https://www.facebook.com/photo.php?fbid=10204982678395343&set=gm.508584672682932&type=3&theater
hoo roo

and wait there's more!!

http://www.jtsonline.com.au/solar-fridge-fan.html

I have two fans.
With an ambient temp of 28 degrees the temp in the cavity behind the fridge exceeds 50 degrees.
Yes hot air rises but needs a flue(chimney) and that is not possible.
With fans on the cavity temp reduces to almost ambient.
Temp inside the fridge also starts to drop.
Not mentioned before is a small 40mm fan inside the suspended by zips and stickybacks to circulate and stop cold air pooling.
Many times in early morning 1am etc I have to switch fans of because the fridge is reaching minus temps.
Also when mobile I run a 600 amp pure sine wave 12/240 inverter to run the fridge on 240v.
This keeps the fridge boiler percolating and it is hot when switched over to gas so no recovery period.
The inverter setup switches of when the ignition switches of.
This fridge is twelve years old and when it dies I will replace it with the same dometic fridge which are now made in china and I believe are even more efficient than the Denmark manufactured models

hi,
The idea from dometic is the heat thermally/convection rises . Best results are with only 25mm clearance wall to rear of fridge .The thermal air then is suppose to all pass thru the condenser and then out a radius bend duct at the top .perfect if not installed in a jayco.

In standard form
1st the gap between fridge is way large 50-75mm can be rectified with sheet foam
2nd if u fit a fan at the top it sucks air from the main cavity which by passes the condenser. The result can be vastly improved

Basically the thermal air travels diagonally from the fridge base towards the fan and then out the exterior top vent.
Some air will also come in from the interior top vent and flow ontop of the condenser and then out the side vent
Jayco Usa installs a duct from the vent to the condenser . Assuming there also must be a fan .

The duct also restricts the air being able to be sucked directly from the boiler . This needs to run reasonably warm and not cooled by fans .
There is a baffle installed in mine to restrict hot air escape from or cold air influence .
The condenser needs to be cooled well but I would be cautious with 2 large fans .

swampy

A couple of issues here,
1. 3 way fridges are not reaaly efficient on 12 v. This will only maintain the temperature you attain by leaving the fridge running on 240 volt 24 hoirs before leaving home.
2. A lot of fridges aren't fitted properly, ensure that, apart from adequate insulation as posted above, make sure that the hot air is able to create a venturi effect and exit via the top vent. I have corrected a couple of installations (in jaycos but I am sure this may be universal) where there is a cavity directly above the top vent that is not blocked off. The result is that the hot air rises inside here and does not create the flow to the exterior of the van, this is more of an issue in caravans as opposed to campervans that hace canvass above the fridge. Even in campervans the top of fridge should be fully sealed, with insulation or otherwise to avoid this hit air pocket as well.
3. Above 30 degrees most of these 3 way fridges will struggle even on gas which is the most effective. Imhave improved cooling on most caravans by installing a good quality 5" computer fan, not the 3" noisy ones. Buy a 12V sealed bearing fan from somewhere like Jaycar for about $30 and install to the inside of the top vent (i have used cable ties for this) positioned to draw air from inside and exhaust to the exterior. Inline with the power I placed a thermo switch (60 degree on) onto,the top of the condensor tube, also obtained from Jaycar. This system is the. Automatic, it switches the fan on when the temperature of the fluid starts to rise in answer ro the rising ambient temperature.
4. After doing all of this you will probably have to put an internal fridge fan inside the cabinet because you WILL freeze the lettuce!

Great info, I have had this issue with my old Jayco, the new Theftford in the van is great

Thanks everyone for the great info, I have paid Jaycar a visit and with their helpful advise, purchased a suitable fan for inside and out, also rectifying the width of the gap so,combined with Greg and all you fellas input hopefully the problem will be solved, making the Lady of the van happy!! A happy lady makes me a lucky man. Cheers Bob.K