Add refrigerator cooling fans

Adding fridge fan options

GOT fan!
Looking down the upper vent discovered fan, how come I don't see the temps others see?

First I am by no means an expert or even that knowledgable-another user & the conclusions I came up in pursuing my mods. Only presenting some options I considered that may or may not apply to your situation. Some of the process that I went thru figuring out what I wanted to do.


Heres a diagram of my stock setup and my new one. Studying this article at RVmobile.com (link nolonger valid) gave me a good understanding of how both the refer and venting worked what might be beneficial.

A discussion thread at RV.netgot me motivated to try and resolve our cooling issues. When its warm outside-actually over 80 our fridge really struggles to keep cool.


Condenser fins located at top of refrigerator

As you can see in pic above, with our side mount refer vent and the condenser at very top against fridge, any rising air will simply go out side vent, no reason to pass thru fins. Part of the design is that the outer wall should be 1/2" from fins to force air thru fins. Our is 4" plus fins are above vent opening. This is where most are deficient. to much gap. Second would be design of box, just gets hot behind refer, forcing it to work harder.

So there are 2 things to look at. One, is to insure air passively is going up thru fins as intended. If the gap between the fins and outside wall is too great less air will pass thru fins. This is more likely an issue on a side mount vented refer than on roof mounted vents. Second would be adding fans to aid in the process. Forcing air thru the condenser fins and extracting the hot air behind refer. How far and involved is up to you.

As noted I wouldn't take any of this as any kind of fact-just my observations.

Though less an issue with a roof mounted vent, fan(s) can help. Simpler because all you need is fan above condenser fins to pull air up and out vent, lil more difficult because of limited access thru refer vent. If however on your roof mounted vent you decided you could use some deflectors, gap too wide, that would be more difficult. Or may be impractical which would make adding fans more beneficial. Even if you cant increase directly air flow thru fins, extracting the ambient hot air will also cool the air around fins.

I have to suggest the simplest method of adding a fan would be to get one of the lil solar powered units. On a side mount running the wires would be only issue. For top mount vent easy, they also make top mount vent covers with a fan built in. I don't know the longevity of these units, air cfm or costs. Now that its mentioned if you decide you don't want/need deflector or go to the effort of installing fans & associated wiring there's still an option.

  • Deflector/baffle

If you visited the thread at RV.net you'll see several different approaches to the baffle/deflector addition. Also different ways of adding fans.And actually a lot of variations in campers in the way refer is mounted and associated venting. So its not a one size fits all. Just a collection of possibilities for those considering this mod to fit your needs

As I noted this is generally more of an issue with side mounted upper vents-though easier to fix if required.

If you have a large gap between the fins and outside wall this might be very beneficial, possibly as much as adding fan. By design air should pass thru condenser fins as it rises, if the gap too large really wont or at least as much as it could. To do this you will need to be creative.

Materials i used was 6" alum flashing material. It was easy to work with,inexpensive, easily cut with old scissors, and I had it on hand. Deflector should allow air to rise passing thru fins before it spills out vent. If you look at my install or at others you might get an idea how to do this simply.

  • Adding fan(s)

Most use the muffin style fan, fairly inexpensive (you'll need to convert mm to inches as they are all sold my mm size). Literary thousands of different cfm, sizes and current usage. I used 3" (80mm) because I doubled the fan mount as deflector mount and want it angled in at top to direct air toward fins.

The simplest fan installation would be half way up wall to move air in the box (area behind refer). A single higher volume fan. This doesn't address however if you have a side mount upper vent & getting air to move around fins, though again dropping ambient helps.

Second is below fins, this would be better for a side vent box, depending on the design of box. In conjunction with a deflector on most setups the most effective. I tend to think more smaller fans vs 1 large fan to get more even air flow across fins-debatable, I think also depends on distance from fins.
On A top mounted vent I would lean toward fan(s) above fins pulling air out. On a roof mount vent likely would be able to hang from ceiling. I am unsure of actual access thru top refer vent.

On side mount vent you'll probably need to make a mount for fans unless far enough down wall to attach. I used some light aluminum angle available at local hwd. Again if you visit the forums you can see what other folks have done to get some ideas.

  • Control

Ok you've decided fans and or deflector now..How do you want to control? Do you want a simple manual switch, auto function, be able to turn off? Is opening up refer access panel ok to do this or do you want switches inside? Easiest obviously would be behind refer. I wanted to see fan function (when on) and inside control. I have enough cabinets I have to open to set up camp :) This will affect how where you install fans or at least insure you have access for wiring. Which brings up last subject wiring..

  • Wiring

. Wiring will depend on the function(s) you want. Can be as simple or as convoluted as you want. Ill show some really basic stuff-but if you can dream up a function, there's a way to wire it.


What I did...there's easier simpler ways...

1st you need a power source. In all cases my suggestion would be use power source that refer controls. Ieee Shut down refer & power is cut to fans. Especially if your refer has safety cut off. If you are running large fans/current draw Id use refer to signal a relay and use 12v from uncontrolled source( ie refer 12v supply terminal). Relays are cheap if required. Some folks tie directly into refer supply terminal but... this leaves the fans always powered (whether set to auto or manual. Could leave you with dead battery, least I'm seeing myself forgetting to turn off fans. I'm unsure as mine was already set up so all power goes thru relays so have full 12v available that is controlled by refer, only power being supplied thru board is what the relay draws. Haven't fried my board so if I were helping someone I'd use a relay, Id also put master switch on relay signal feed. so in winter etc and your not using fans your not unnecessarily energizing relay, minimal power usage but a drains a drain. But that's me, entirely up to you.

  • Opt.1 The simplest wiring options is to run fans(s) manually. Run a hot wire thru an on/off (SPST) switch. I wouldn't recommend this because run 24/7, you need to remember to turn off, at night, batts low, storage etc.but simple

  • Opt. 2 Second would be hot wire thru on/off (SPST switch but also thru a thermo disk before it reaches fans(s). Better than 1 but still requires manually turning off for storage etc. plus on this is it wont run during the night or when not needed, cant manually over ride to turn on if wanted.

  • Opt. 3a Third would be thru on/off/on switch (SPDT w/ center off) that selects either constant on , on thru thermo button(auto) or off. 2 separate SPDT switches could be used, i for each circuit, which would also give you the off.
    On all options you could use switch with pilots if you wanted, light in the switch is easier than running separate pilots. I used an SPDT switch as power source selector and I've never seen these with pilots and I wanted pilots so used all the same switches . .


  • Opt 3b Same as 3a :Could be advantageous in some apps to run single power wire to SPDT switch then to selected either thru thermo disk or directly to fans. An SPDT switch can be wired either way, selecting what your feeding or where you get power..
  • Opt 4 Functional the same but using 2 spdt switches to control fan(s) separately. We could go on for days. But I could see setting up so you have say center fan on-if temp really climbs outer fans kick on auto.

  • then there's using DP3T or DP4T slide switches to progressive turn on fans etc like your dual bulb light fixture. Or tying in diodes, like I used to control interior fan- SPDT center off one side is one fan other side is both fan. Again I'm not showing -I'm just saying...

    All this page is to show the simpler ways to wire it up. I used toggle switches and separate pilots lights. I know it might be difficult but I'd at least on a manually operated system stick a pilot somewhere you'll see.

    If you get on line and search "add fan to refrigerator" "refrigerator fans" etc and variations of that you'll find TONS of mods, how tos and whys most of which will be a clearer and informative than this-just my effort.

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