# Connecting fridge fan



## barge1914 (Mar 14, 2018)

We’ve got a domestic three way fridge and want to connect a fridge fan. What is the best place to make the electrical connections to?


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## trevskoda (Mar 14, 2018)

On the 12v to switch feed side,do fit a small inline switch.


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## n brown (Mar 14, 2018)

you can get a temperature sensing twin fan kit from CAK Tanks


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## Neckender (Mar 14, 2018)

Our kit came pre wired with a switch I just connected to the hab batteries with a fuse.

John.


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## gypo (Mar 14, 2018)

Sounds interesting why are people fitting Them? 

Can someone put a link up for the fan kit, anymore info would be good.
Thanks
D


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## izwozral (Mar 14, 2018)

Ian, I fitted two 'silent' computer fans Gelid Solutions Silent 6CM 60mm Fan Cooler Case PC Computer Cooling 3 Pin Quiet  | eBay

Seperate on/off switch to turn fans on 5 x 12V ON/OFF Switch Car Smart Switch Round Rocker Van/Dash/Boat LED/Light BLUE  | eBay

One of these: 3in1 Digital LED Display Temperature Thermostat Refrigeration Heating Controller  | eBay 

I found it a bit fiddly to do but a numpty like me did it and it worked a treat. It certainly made a difference, one hot day it dropped the temperature 5 degrees.

If I can find the pics I will post them.


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## izwozral (Mar 14, 2018)

gypo said:


> Sounds interesting why are people fitting Them?
> 
> Can someone put a link up for the fan kit, anymore info would be good.
> Thanks
> D



Some fridges struggle to keep the temperature down in hot weather, by fitting fans into the upper vent, it sucks the hot air that builds up behind the fridge and blows it outside.

I fitted two fans side by side in a frame made from pvc trunking, very light and easy to glue to the inside of the vent.


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## gypo (Mar 14, 2018)

izwozral said:


> Some fridges struggle to keep the temperature down in hot weather, by fitting fans into the upper vent, it sucks the hot air that builds up behind the fridge and blows it outside.
> 
> I fitted two fans side by side in a frame made from pvc trunking, very light and easy to glue to the inside of the vent.



My fridge seems to be ok what ever the weather, would fitting one tho improve efficiency?
I’m always up for tinkering about with the van 
Cheers
G


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## runnach (Mar 14, 2018)

gypo said:


> My fridge seems to be ok what ever the weather, would fitting one tho improve efficiency?
> I’m always up for tinkering about with the van
> Cheers
> G


 In the most basic of explanations refrigeration is shifting heat from one place to another, By fitting fans you are increasing airflow and allowing a better disappation of heat. In practical terms the fridge should be more efficient

Channa


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## Deleted member 62288 (Mar 14, 2018)

*The other type of fridge fan*



izwozral said:


> Some fridges struggle to keep the temperature down in hot weather, by fitting fans into the upper vent, it sucks the hot air that builds up behind the fridge and blows it outside.
> 
> I fitted two fans side by side in a frame made from pvc trunking, very light and easy to glue to the inside of the vent.



The other type of fridge fan is fixed inside the fridge compartment, up against the cooling fins, ensures air is gently circulated,

I'm looking for one of these as my fridge keeps going into random defrost every 10 days or so.

article: (It's the website's warning, not mine)
WARNING: RV Refrigerator Fan. What You NEED To Know

video:
YouTube

james


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## trevskoda (Mar 14, 2018)

Neckender said:


> Our kit came pre wired with a switch I just connected to the hab batteries with a fuse.
> 
> John.



What a long way round to do things,12v behind switch at fridge which is about 1ft away.


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## gypo (Mar 14, 2018)

channa said:


> In the most basic of explanations refrigeration is shifting heat from one place to another, By fitting fans you are increasing airflow and allowing a better disappation of heat. In practical terms the fridge should be more efficient
> 
> Channa



Thank you channa,
Where is the fan positioned?
Thanks
G


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## Deleted member 62288 (Mar 14, 2018)

*nicer internal fridge fan video*

nicer internal fridge fan video

HookTube 

(hooktube is a front-end for youtube, it strips out the garbage and adverts, just gives you the videos)

james


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## trevskoda (Mar 14, 2018)

gypo said:


> Thank you channa,
> Where is the fan positioned?
> Thanks
> G



Behind top outlet vent.


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## n brown (Mar 14, 2018)

i reckon the best place is on the inside of the top vent , blowing out .


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## Neckender (Mar 14, 2018)

trevskoda said:


> What a long way round to do things,12v behind switch at fridge which is about 1ft away.



On our last van the fridge was next to the settee with leisure batteries beneath and I found it quite easy to wire up.

John.


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## QFour (Mar 14, 2018)

I have three behind the top vent so extracting the air from behind the fridge. Some of the fans can be a bit noisy when run on 12v so I have the option to switch in a resistor to reduce the voltage which makes them much quieter.


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## torwood (Mar 15, 2018)

these three pictures show the top of my Dometic fridge with the internal fridge wiring, I tapped into the 12 volt as marked.   My temperature control I mounted on the front fascia on the left and a rocket switch on the right to isolate the fans.  I clipped temperature probe to the radiator fins at the rear of the fridge.


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## mid4did (Mar 15, 2018)

Probably cant get these fans anymore since maplins has gone bust. 
YouTube


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## torwood (Mar 15, 2018)

mid4did said:


> Probably cant get these fans anymore since maplins has gone bust.
> YouTube



I got my fans from old PC towers, most are thrown away these days, speak to your local computer repair shop, just make sure they are 12 volt.  Cost was zero for me.


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## barge1914 (Mar 15, 2018)

*Fridge fan*



n brown said:


> you can get a temperature sensing twin fan kit from CAK Tanks



They don't sell these any more.


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## barge1914 (Mar 15, 2018)

izwozral said:


> Ian, I fitted two 'silent' computer fans Gelid Solutions Silent 6CM 60mm Fan Cooler Case PC Computer Cooling 3 Pin Quiet  | eBay
> 
> Seperate on/off switch to turn fans on 5 x 12V ON/OFF Switch Car Smart Switch Round Rocker Van/Dash/Boat LED/Light BLUE  | eBay
> 
> ...



Thanks. Sadly the delivery on the last item is not until late April/May. too late for us.


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## barge1914 (Mar 16, 2018)

*fridge fan*



torwood said:


> View attachment 61970View attachment 61971View attachment 61972 these three pictures show the top of my Dometic fridge with the internal fridge wiring, I tapped into the 12 volt as marked.   My temperature control I mounted on the front fascia on the left and a rocket switch on the right to isolate the fans.  I clipped temperature probe to the radiator fins at the rear of the fridge.



Hi
Is this the same unit you used.. 12V Digital LED Display Temperature Controller Thermostat w/ Sensor MH1210A ://uk.suntekstore.com/goods.php?id=14009051&utm_source=gbuk&utm_medium=paid

I note it says voltage 12v + or - 10%. How is yours managing, as charging voltage exceeds this at 14.4V. Have you added something to limit voltage?


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## torwood (Mar 16, 2018)

barge1914 said:


> Hi
> Is this the same unit you used.. 12V Digital LED Display Temperature Controller Thermostat w/ Sensor MH1210A ://uk.suntekstore.com/goods.php?id=14009051&utm_source=gbuk&utm_medium=paid
> 
> I note it says voltage 12v + or - 10%. How is yours managing, as charging voltage exceeds this at 14.4V. Have you added something to limit voltage?


Yes - no issues so far, fitted it last year.


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## gypo (Mar 17, 2018)

izwozral said:


> Ian, I fitted two 'silent' computer fans Gelid Solutions Silent 6CM 60mm Fan Cooler Case PC Computer Cooling 3 Pin Quiet  | eBay
> 
> Seperate on/off switch to turn fans on 5 x 12V ON/OFF Switch Car Smart Switch Round Rocker Van/Dash/Boat LED/Light BLUE  | eBay
> 
> ...



Just be aware that the controller In the link is 240v not 12v
D


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## Tezza33 (Mar 17, 2018)

I fitted one of these to my fans, the temperature probe can be extended to lay on top of the fins on the back of the fridge


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## QFour (Mar 20, 2018)

I used an Audrino Micro Computer to switch mine on and off. It has a control panel which shows the temp in the area behind the fridge and shows if the fans are on high or low speed or off. I have three fans connected and a temp sensor. Nothing happens until it gets to 30 degrees. Then the fans switch on to low speed. If the temp still rises and gets beyond 38 degrees then the fans switch on to high speed. To stop the fans oscillating on and off they switch on for 4 minutes before the program checks the temp again.

First trial in Spain last year showed that the fridge temp can reach 36 degrees and the fans on low speed can drop the temp down to 30 degrees. On really warm days or if the fridge vents are in the sun then you can get 40 degrees behind the fridge. Fans on high would lower the temp but it struggled to get down to 30 degrees.


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## gypo (Apr 1, 2018)

trevskoda said:


> What a long way round to do things,12v behind switch at fridge which is about 1ft away.


By connecting to the 12v supply to the fridge doesn't this mean that the fan will only get power when the engine is running and powering the 12v supply to the fridge of and not all the time ie when on gas from eg?
Thanks
G


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## runnach (Apr 1, 2018)

gypo said:


> By connecting to the 12v supply to the fridge doesn't this mean that the fan will only get power when the engine is running and powering the 12v supply to the fridge of and not all the time ie when on gas from eg?
> Thanks
> G



No there is a permanent 12 v feed for the igniter, separate to how you are thinking 

Channa


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## gypo (Apr 1, 2018)

OK thanks 
G


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## gypo (Apr 21, 2018)

I’ve installed my fan now, I’m just wondering where is the best place to put the temperature sensor? I find if I put it just in front it between the fins and the fans when you switch it on what happens is the fans draw the warm air over it from the fridge and send the temp reading up so you are not really able to balance it.
Thankg


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## torwood (Apr 21, 2018)

gypo said:


> I’ve installed my fan now, I’m just wondering where is the best place to put the temperature sensor? I find if I put it just in front it between the fins and the fans when you switch it on what happens is the fans draw the warm air over it from the fridge and send the temp reading up so you are not really able to balance it.
> Thankg


I clipped mine to the radiator fins, conduction beats convection!


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## gypo (Apr 21, 2018)

Great thanks
G


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## gypo (Apr 22, 2018)

hairydog said:


> The point of the temerature sensor is to detect warmth in the area that the fans cool.
> So it should be in the area between the fridge's warm fins and the top vent.
> If that area gets warm, it should turn the fans on until that area gets cool again.
> That's what it is for!



This is what I’ve done, however putting it between the fins and fans doesn’t exactly work properly if you are using a temperature type controller like the ones mentioned earlier in this thread because when you fit the sensor where you say the fans pull the warm air from the fins over it sending the readings up. However fitting it like torwood has said now works!


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## Deleted member 207 (Apr 22, 2018)

Late onto this thread as usual.

First up the fan should be placed so that it blows cold air sucked in from the outside - so close to the bottom vent if possible but above the bottom baffle.
Second, the fan air should be blown over the cooling fins and out of the top vent. Sucking warm air is not as effective as blowing cold air!!!
Third, the installation should be in accordance with the fridge designers requirements - not the vehicle builder's cheapest method. There should be two baffles on the back of the fridge that creates a chimney effect. The lower baffle should direct cold air to the lower part of the fridge and ensuring that the "chimney" draws. The top baffle should direct heat out of the top vent.
If you goto https://caravanandmotorhomebooks.com/make-caravan-fridges-work-as-claimed/ you can find detailed information on fitting, fans and baffles.


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## gypo (Apr 22, 2018)

Thank you


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