how meny rpm fan for frig exhaust stack

[midnightsadie]

I,d like to install a exhaust fan in the back of my frig to help pull the heat out. my exhaust is on the side of the rv ,not the top. this is for the heat and flue exhaust. how big a fan, in rpm,s

[SCVJeff]

The Logans wrote:
Hi SCVJeff,

Where did you bring in the 12v power from, in the fridge compartment, and where did you get the thermostat?

Thanks!

there is power already in the compartment as the fridge requires it anyway. As far as the thermostat, MY fans will be controlled by an ARP fridge protection device, but if I didn't have that I would be using the existing fridge fan Clik switch that runs the existing factory fans that are famous for dieing. If you need to buy one, I have seen them on eBay, or something like THIS from RVCoolingunit.com. David has all the various fans in stock, although not the super silent NOCTURA and I'm also not sure about their IP ratings.

[SCVJeff]

(Double post)

[The_Logans]

Hi SCVJeff,

Where did you bring in the 12v power from, in the fridge compartment, and where did you get the thermostat?

Thanks!

[SCVJeff]

There are lots of ways to do this. You can buy kits with lots of hardware you may or may not use. Just be conscious of the vast differences in fans out there. You want ball bearing, NOT a sleeve bearing for sure. After that be aware that this fan can be in a really dirty, sometimes hot environment. Dust, and salt where we camp, will and has killed most of these cheap fans. Make sure you find a fan with an IP rating of 55+ and it will run forever.

Here's my install on the roof vent with Noctura NF-F12 IP65 fans. All 4 running at full speed are barely heard if you stick your ear in the lower fridge vent, and not at all inside. They will run at 40% but can be turned up in hot environments. NONE of the fans listed above will be anywhere close to being as quiet as these. They are also rated for environments of 250 degrees, not that it'll ever get that hot, but it's a lousy place to be a fan.

You don't rate fans on RPM, you rate them on CFM, but typically the larger the fan, the slower it will turn to produce the same flow. The top of the thread fan is several sizes smaller than the 120mm fans I am using for the same flow. Meaning the 120mm fans won't work nearly as hard for the same air.

[mvpmich]

And add one of these
https://www.google.com/search?q=12+volt+rv+refrigerator+exhaust+fan+temp+sensor&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari
to the fins at the top of the fridge and wire to fan so it only runs when temps in exhaust chase are high

[Halmfamily]

I added three computer fans, like above, blowing out the top side vent. Added a thermostat so only turns on when heat builds up. Works great. Purchased my fans off of Amazon for $5 each and thermostat was $7 if remember correctly.

[352]

HERE. Inside and out