12volt fans for 3 ways frigs any good.

Hi Scoof

I did an experiment mid summer with my kmart 3 way fridge in a closed shed. In summer temperatures (33 ish) with no fan fitted it struggled to reach 14 degrees. This was in an enviroment with no breeze. With a small computer fan fitted to the rear forcing air up through the rear workings of the fridge, the temp dropped by 8 degrees. If the fridge was placed in an airy position the difference was negligible. So in summary yes it's good for example in the back of the car where their is poor air circulation. I also tried this experiment with a 12v Bushman fridge and found to my surprise no difference at all in the performance of the fridge. In this case I set the fridge to a constant 6 degrees and measured run time of the compressor to maintain that temperature over an extended period.

regards Kc

Hi Scoof,
I think kc's answer says it. I have a compressor Autofridge which runs in an enclosed space, and I use two 100mm computer fans to shift air each side of the fridge (the fridge condenser in placed on each side of the fridge) and it makes it quicker in pulling down the temp. The fans were ripped out of old computer power supplies (turn off the computer first!).

As an aside, back in the late 60's, I was supplied with an industrial caravan on a work job on the Nullarbor and was despairing with the poor performance of the Electrolux 2-way fridge. It was poor on gas and wouldn't work at all on 240v. In the end, I managed to get the fridge out, and found that the ventilation around the fridge was almost non-existent, the installation almost contrary to the supplied install book, so I removed the top over the fridge. The other thing I found was the 240v lead just coiled up under the fridge, not connected to anything! An extension cord was arranged and after that, the fridge worked quite well. And this was from a well-known caravan mfr.
Cheers,
Gerry

I have 2 X 12v pooter fans blowing the hot air out the top external vent of the fridge and this has helped our fridge immensely.
They are controlled by a thermo switch that turns them on when the temp above the rear coils? workings gets hot.

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Hi scoof,

This is info on how to fit fan's to a caravan 3 way fridge both internally and externally. I found it useful as it works well.
Thought it may be of interest.

Wazzaaaa

HI Scoof,
have a look at this site, may answer all your questions,
Butch 58.

www.dreampod.net-boroma-fridgefan.html

I have installed a 4" computer fan in the top vent of our 3way and have seal the remainder of the vent with a piece of Perspex and installed baffles so air can only pass over the fins. Seemed to improve things a bit.

Our van came with 2 x 70mm computor fans on brackets behind the top vent to blow air out. Controlled from a thermo switch on the R/H end of the condenser fins with a master switch to switch off. (why that, I dont know?)


However, the way the boiler flue is ducted, with an open ended T piece (lower than the outside end) flue gas was sucked back in and across the condenser fins then blown out through the main vent whilst the fans were running. The setup which in theory is good did not work as well as I thought it could. I reckoned the condenser was not getting as cool as would be optimum.
On days above 35deg. the cabinet temp would creep up to around 5, the freezer remaining at -15/18.

My modification could be seen as "overkill", but I removed the 2 fans/brackets and made a frame to fit directly below the condenser fins with the fans blowing up and through. I also fitted an additional fan making 3 in a row. I then blocked off any other gaps in front and sides of the fans so that all cooling air has to pass through the fans, even when not running. I also changed the switch so that I can switch the fans on, over riding the thermo switch

The effect was immediate. No longer is the boiler flue gas going past the fins, it all comes out through the outer vent. Condenser fins remain cool, the cabinet temp. has not gone over 1.5deg. even at 37deg. ambient. (that was running the fans 24/7 which I have been tending to do). Thermostat setting on 2.

The slight noise heard inside the van is not distracting, and at around 0.4a./hr. is a usage of only 9.6a.hrs./day, easily managed.
For anyone interested I can email photo.
furph

Using a thrmo switch like the 50 degree Jaycar model is one way to control the fan, but it is either on at full load, or off.

Another way to do it is to use a Thermistor, the t/mistors resistance changes with temp. so the fan would start very slowly and speed up as required.

Check out the circuit here www.technonogystudent.com/elec1/therm1.htm

For any of you young turks out there you will see that the LED in the circuit could be replaced with a 2n3055 transister which could carry the load of a small fan, the circuit would need some minor adjustments and would only cost a few $s

Have a look at the circuit and tell me what you think.

Cheers

piddlefimp

Oops,

www.technologystudent.com./elec1/therm1.htm

piddlefimp

Hi Scoof
I have just finished fitting fans to my electrolux 3 way in my camper.
I shrouded the condensor with minimal gaps and used one fan to suck the air thru rather than blow air thru. On mine the heater flue and condensor air used the same exhaust point and hot flue gas could travel accross to the condensor fins so I put in a divider between the two. As I dont use mine on 240 volt I have disconnected the power lead and use the thermostat to control the fans
and the cool down time has been greatly reduced Hope this makes sense.
If you need any info call me on 0409725793

Greenant

Scoof
No mine looks like a bar fridge with a front opening door built in to make a bench on top of it. With the bench top off I can get to all the controls etc

Greenant