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GordonThree's avatar
GordonThree
Explorer
Aug 06, 2018

Overkill Fridge Fan

A while back in another thread I mentioned buying two 3000 RPM 24 volt industrial fans for using to power vent my fridge on very hot days, to help improve efficiency.

I finally got around to installing them. I went with two Noctua iPPC 24v 3000RPM units, IP67 rated. They support pwm speed control but I'm currently not using that feature.



The fans are installed using silicone pegs? on a piece of aluminum angle stock. I re-used two mounting screws that hold the factory air damper in place.

The fans connect to a piece of 18ga cable which runs down to the bottom of the vent, where it's connected to a 12-24v boost converter and remote switch that is tapped into the fridge 12v supply.



I became overwhelmed by mosquito as I was installing the remote switch and didn't grab a picture. I'll try again shortly. The remote switch toggles on when ambient is above 85F and off at 82F, probably lower than it needs to be but 90-100 degree days are very rare in these parts.
  • GordonThree wrote:
    A while back in another thread I mentioned buying two 3000 RPM 24 volt industrial fans for using to power vent my fridge on very hot days, to help improve efficiency.

    I finally got around to installing them. I went with two Noctua iPPC 24v 3000RPM units, IP67 rated. They support pwm speed control but I'm currently not using that feature.



    The fans are installed using silicone pegs? on a piece of aluminum angle stock. I re-used two mounting screws that hold the factory air damper in place.

    The fans connect to a piece of 18ga cable which runs down to the bottom of the vent, where it's connected to a 12-24v boost converter and remote switch that is tapped into the fridge 12v supply.



    I became overwhelmed by mosquito as I was installing the remote switch and didn't grab a picture. I'll try again shortly. The remote switch toggles on when ambient is above 85F and off at 82F, probably lower than it needs to be but 90-100 degree days are very rare in these parts.


    I assume those are installed in the bottom vent area and I wonder how much they really will help since I would worry just how much they really increase the flow over the coils and increase the air flow out of the roof vent. They amount of turbulance and potential blow back could really impair the overall efficiency in what you really want to achieve. In other words in this case too much might not be better and I would think there is an optimum balance in air flow out of the roof vent.

    My ARP with optional fan control has specific temp ranges for when the optional fan comes on and when it goes off.

    Larry
  • midnightsadie wrote:
    I.ve though about those auto fans, if I read it right they pull alot of amps.


    They can, but that's at full speed.

    I have a smaller fan from another project it's about 60 watts at full speed, but with a PWM controller I can dial it down to about 12 watts and it still moves a lot of air, but is less tolerant of any resistance on the discharge.
  • stevemorris wrote:
    im going to get a 12 volt automotive radiator fan, should be plenty for around here!(Ontario and eastern Canada)
    our fridge is side vented bur not in a slideout, it has a small noisy fan somewhere in the "chimney" space, I can hear it


    I was looking at those (10" & 14") on Fleabay. Seems like they would work great and you can even get speed controls for them.
  • theoldwizard1 wrote:
    I am certain you could have found 12V fans which would have eliminated the boost converter.


    Please make a suggestion. 270cfm at roughly 12 mm/hg at under 10 watts. Ip67 protection.

    I found some from Delta minus the ip67 at over $40 each.

    I think the higher voltage allows for more torque without adding a lot of mass to the motor?
  • im going to get a 12 volt automotive radiator fan, should be plenty for around here!(Ontario and eastern Canada)
    our fridge is side vented bur not in a slideout, it has a small noisy fan somewhere in the "chimney" space, I can hear it
  • I am certain you could have found 12V fans which would have eliminated the boost converter.
  • No such thing as too much air. I have four 100CFM fans on my roof vent.

    Bill
  • Like your install. Be interested to here you think when using them also. Thanks.

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