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