Fridge fans again.

[Jcloughie]

In my last Lunar caravan I fitted a fridge fan made from bit I bought from China. It worked beautifully, it could just be heard turning on and off during daytime hot weather. And the fridge was noticeably cooler in 36 degree temperatures.

I have just purchased a new fan kit for our new van. But after using the van for a few days in quite hot weather and being very impressed with the fridge and freezer operation. I may not fit it.

But, if I do, I may first make a modification to the kit. And I am looking for some advise.

I have tested the kit with a USB power supply and it works well. But I had to first decipher the controls. If anyone wants to purchase they are available on eBay, Amazon and AliExpress. I paid £13.

Instructions:

• Power up
• Press left button once
• Scroll through until screen shows ‘P0’
• Press left button to select
• Use arrows to set the temp the fans should turn on, (say 32, needs trial and error)
• Repeat, but setting with P2 and set the lower temp at which the fans will turn off.

Instead of using a USB power supply. I am considering wiring directly to the 12 volt circuit via a fuse. The control box should be fine, as it says 12 volt on the back. But the fans are rated at 5 volt..

I would re-wire these in series, which might put around 7 volts in use. (I think the will just run a bit faster, if they blow, so be it. 12 volt fans are cheap enough).

Any comment on my logic.





John

 

[noggin16460]

In my last Lunar caravan I fitted a fridge fan made from bit I bought from China. It worked beautifully, it could just be heard turning on and off during daytime hot weather. And the fridge was noticeably cooler in 36 degree temperatures.

I have just purchased a new fan kit for our new van. But after using the van for a few days in quite hot weather and being very impressed with the fridge and freezer operation. I may not fit it.

But, if I do, I may first make a modification to the kit. And I am looking for some advise.

I have tested the kit with a USB power supply and it works well. But I had to first decipher the controls. If anyone wants to purchase they are available on eBay, Amazon and AliExpress. I paid £13.

Instructions:

• Power up
• Press left button once
• Scroll through until screen shows ‘P0’
• Press left button to select
• Use arrows to set the temp the fans should turn on, (say 32, needs trial and error)
• Repeat, but setting with P2 and set the lower temp at which the fans will turn off.

Instead of using a USB power supply. I am considering wiring directly to the 12 volt circuit via a fuse. The control box should be fine, as it says 12 volt on the back. But the fans are rated at 5 volt..

I would re-wire these in series, which might put around 7 volts in use. (I think the will just run a bit faster, if they blow, so be it. 12 volt fans are cheap enough).

Any comment on my logic.

View attachment 9167

View attachment 9168

John

Any chance of a link please

 

[Jcloughie]

Any chance of a link please

There are other choices, try googling,

USB Powered 80mm Quiet Cabinets Cooling Fan Adjustable Thermostat Control

Or

12 volt Powered 80mm Quiet Cabinets Cooling Fan Adjustable Thermostat Control

Otherwise:

EBay

Amazon

Ali Express

John

 

[Beachball]

There are other choices, try googling,

USB Powered 80mm Quiet Cabinets Cooling Fan Adjustable Thermostat Control

Or

12 volt Powered 80mm Quiet Cabinets Cooling Fan Adjustable Thermostat Control

Otherwise:

EBay

Amazon

Ali Express

John

At very reasonable price 🙏

 

[ProfJohnL]

With the exception of the output voltage you have suggested, the rest of the plan seems logical.

The reason I question your output voltage is these sorts of device are likely to use a relay to control their output power, so the output voltage is more likely to be the same as the input voltage. in your case 12V.

I do wonder if putting the two 5V fans in series and running them on 12V, might make them too noisy.

I have often fitted fans to pieces of electronic test gear, and its quite common for example to use a 24V fan just running on a 12V supply, for situations where only a light air movement or low noise is required.

 

[Mr Plodd]

For many years I have fitted 12v computer cooling fans to the fridge top vent, and wired them through a small illuminated switch fed from the 12v lighting circuit (that ensures if the master switch is off so is power to the fans)
Total cost less than £15 and the system works a treat.

 

[laurenmcsporen]

I followed a Trudigan utube video & fitted my own. It works a treat & very easy fit using a 12v computer cooling fan.

 

[Jcloughie]

With the exception of the output voltage you have suggested, the rest of the plan seems logical.

The reason I question your output voltage is these sorts of device are likely to use a relay to control their output power, so the output voltage is more likely to be the same as the input voltage. in your case 12V.

I do wonder if putting the two 5V fans in series and running them on 12V, might make them too noisy.

I have often fitted fans to pieces of electronic test gear, and its quite common for example to use a 24V fan just running on a 12V supply, for situations where only a light air movement or low noise is required.

Good points, I have brought the kit home and will rig it for a test run on 12 volt when I get the chance. It will be easy to revert to 5 volt in pattelel.

John

 

[ProfJohnL]

Good points, I have brought the kit home and will rig it for a test run on 12 volt when I get the chance. It will be easy to revert to 5 volt in pattelel.

John

Why in parallel? If the unit produces the battery voltage at its output, that means it could be as high as 13.8V when the battery is charging. With the fans connected in parallel, they will both see the same voltage which could be as high as 13.8. that would be 8.8V too much, and is very likely to destroy the fan motors.

Even if the fans are connected in series their combined voltage requirement is a maximum of 5+5 = 10V. Again if the battery is being charged, they will see 3.8V too much and bearing in mind the way 5V gear is designed, that could still be enough to damage them At best it will over speed the fans making more noise, and it might add too much air movement across the back of the refrigerator, reducing its cooling ability.

Its best to stick with 12 or 24V fans

 

[Jcloughie]

Why in parallel? If the unit produces the battery voltage at its output, that means it could be as high as 13.8V when the battery is charging. With the fans connected in parallel, they will both see the same voltage which could be as high as 13.8. that would be 8.8V too much, and is very likely to destroy the fan motors.

Even if the fans are connected in series their combined voltage requirement is a maximum of 5+5 = 10V. Again if the battery is being charged, they will see 3.8V too much and bearing in mind the way 5V gear is designed, that could still be enough to damage them At best it will over speed the fans making more noise, and it might add too much air movement across the back of the refrigerator, reducing its cooling ability.

Its best to stick with 12 or 24V fans

At present, on USB, both fans are seeing their designed voltage of 5 volt. If I supply 12 volt, which is the designed voltage of the control unit, the output could be 13.8 volt as you say, which is why, in post #1 I said that if I wired them in series the fans may see up to 7 (ish) volts. The fans may simply run faster, they may be noisier they may even blow. In that case I will just use the same control unit with 12 volt fans back in parallel.

I wonder if you missed the word ‘revert’. In #8. I was thinking of going back to USB supply in that case. I did not make that clear enough.

John

 

[toad a caravan]

I myself fitted PC fans in mine,as Mr Plodd has,I used a second hand Corsair( the brand) these are known for being very quiet and reliable,the generic fans fitted in PC,s can be noisy hence the fitting of Corsair fans

 

[trevormonty]

12v PC fan with manual switch is cheapest low tech solution and works. Just buy ine with biggest diameter fan that will fit ideally low noise check specs. I turn mine off at night as slight noise bothers me, but then again cooler at night so not really needed.

For accurate fridge temp monitoring place glass of water in it and check water temp every so often. NB water temp will be food temp.

 

[otherclive]

12v PC fan with manual switch is cheapest low tech solution and works. Just buy ine with biggest diameter fan that will fit ideally low noise check specs. I turn mine off at night as slight noise bothers me, but then again cooler at night so not really needed.

For accurate fridge temp monitoring place glass of water in it and check water temp every so often. NB water temp will be food temp.

I would turn our fridge fans off at night for the same reason, but my wife was oblivious to it.

 

[Jcloughie]

The fans I am suggesting are about £13 the lot.

Once in, totally automatic. No intervention required. What’s not to like?

As it goes cooler at night. They will not come on. During the heat they cycle on and off, in my last set up you could just hear it switching. But this one is quieter.


John

 

[Boxerman]

For many years I have fitted 12v computer cooling fans to the fridge top vent, and wired them through a small illuminated switch fed from the 12v lighting circuit (that ensures if the master switch is off so is power to the fans)
Total cost less than £15 and the system works a treat.

Why do people fit the is it better than leaving the fridge as standard?

 

[otherclive]

Helps fridge performance in hot weather by aiding the ventilation across the rear of the fridge. I used them firstly for trips to south France with temperatures regularly above 30 deg C.

 

[Boxerman]

Helps fridge performance in hot weather by aiding the ventilation across the rear of the fridge. I used them firstly for trips to south France with temperatures regularly above 30 deg C.

Do I fit them in the fridge or somewhere else?

 

[otherclive]

Do I fit them in the fridge or somewhere else?

Behind the fridge where the external vents are. Some fit them near the lower vent in order to move the warm air up and introduce cooler air. I fitted mine behind the upper external vent to help remove the warm air such that cooler air enters via the lower vent. But not too certain if either location is better than the other. There are lots of videos on YouTube showing how to do it. I kept mine simple with just two fans thermostatic controlled with an integrated on off switch. Price ranges from very expensive Dometic to a just as functional DIY kit for just a few pounds.

How to fit a CBE fridge fan kit - Practical Caravan

Installing a fridge fan can boost your fridge’s cooling power, which is especially useful in hot weather. Nigel Hutson shows you how.

www.practicalcaravan.com

 

[Boxerman]

Behind the fridge where the external vents are. Some fit them near the lower vent in order to move the warm air up and introduce cooler air. I fitted mine behind the upper external vent to help remove the warm air such that cooler air enters via the lower vent. But not too certain if either location is better than the other. There are lots of videos on YouTube showing how to do it. I kept mine simple with just two fans thermostatic controlled with an integrated on off switch. Price ranges from very expensive Dometic to a just as functional DIY kit for just a few pounds.

How to fit a CBE fridge fan kit - Practical Caravan

Installing a fridge fan can boost your fridge’s cooling power, which is especially useful in hot weather. Nigel Hutson shows you how.

www.practicalcaravan.com

Thanks for the pointer I appreciate it as I don’t have much experience with electrics and fridges , repairing plastics , paint and trim occupied 30 + years of my working life but electrical stuff is a whole new adventure

 

[Dustydog]

Many years ago our good Forumite Sproket fitted cooling fans , top and bottom if I remember correctly.
I bought two fans but never fitted them. Still,onboard awaiting their call😉

In practice I can’t say the fridge has under performed even in the very recent scorcher.

However the one issue that happens very often over more than one week is the build up of heavy frost/ice on the fridge and freezer cooling vanes.
Is this because we cram too much in or just one of those working things or would the fs s help?

 

[otherclive]

Thanks for the pointer I appreciate it as I don’t have much experience with electrics and fridges , repairing plastics , paint and trim occupied 30 + years of my working life but electrical stuff is a whole new adventure

Wouldn’t be expensive to have a caravan engineer (AWS/MCEA) or local dealership fit something you supply.

 

[Boxerman]

I am probably capable as I have fitted stuff to one of my motorcycles but if it looks beyond me I will get the service guy who used to work for me , I don’t get on particularly well with the dealer, it seem he wasn’t impressed when I said next time you give me a bill can you wear a mask and hold a knife the at least I can say I was robbed at knifepoint 🙈

 

[Boxerman]

Wouldn’t be expensive to have a caravan engineer (AWS/MCEA) or local dealership fit something you supply.

Isn’t it weird that the Bailey 640 + I have has the fridge vents on the side where the awning fits that must add to the problem ? what that about ?

 

[borderbilly]

What's warm weather 🤔

 

[toad a caravan]

Warm weather is what's often discussed but rarely seen