I'm working on my DIY conversion build out of a 2010 Ford extended E250.I've red a lot of articles here and there about 3 way refrigerator venting, now I can't do the big two gravity vents/access door like they normally do.But Here's another way that should provide even more air movement behind the fridge.Using three 80mm PC fans (120cfm/0.54amps total), plugged to the fridge (I don't know how yet but I know there's a circuit especially for that) every time the fridge turns on the fans are activated.I have never done this before, please tell me if you see anything wrong with this concept, thanks!

Why not make that 12" x 12" access door a vent, instead? These work well, and are screened:soffit ventThey come in aluminum, white and brown.You could even hinge it on the bottom, and have 4 screws along the top. And put some 1/8" x 1/2" foam gasket in behind to keep the rain out.I have several of these on my minibus conversion. I cut them to size... one, two, or three sections.Two of those fans should be plenty... and only required during hot weather.

It looks like the back of the fridge is too far from the wall. The installation instructions want the back of the fridge within something like 1/2 to 1" (check instructions). Otherwise the flow of air may go around the tubes rather than through them.Also, since the top vent has to go around a corner, I would add a fan.

There are current installations in RVs that do use a fan(s) to dissipate heat from the back of the unit. My installation uses a thermal switch to control the fan in the back.

ScottG wrote:It looks like the back of the fridge is too far from the wall. The installation instructions want the back of the fridge within something like 1/2 to 1" (check instructions). Otherwise the flow of air may go around the tubes rather than through them.Also, since the top vent has to go around a corner, I would add a fan.Yes I have red about that also, actually I drew the fridge from the online PDF manuals, I don't have actual scaled drawings of the fridge itself but if you look closely at my drawing there's a dashed line near the rear top, that represents the rear components, I planned on leaving 1/2" clearance with the plywood wall, so the air will sweep thru the backing and capture the heat.For the fans, in my design I have 120cfm total (40cfm x 3) the space in the back of the fridge is about 3 cubic feet, so basically it will take under 1 second to evacuate all the air in the back of the fridge and replace it with fresh air, you think that's not enough? I wonder how long gravity takes to vent the back for those without fans? jrnymn7 wrote:Why not make that 12" x 12" access door a vent, instead? These work well, and are screened:soffit ventThey come in aluminum, white and brown.You could even hinge it on the bottom, and have 4 screws along the top. And put some 1/8" x 1/2" foam gasket in behind to keep the rain out.I have several of these on my minibus conversion. I cut them to size... one, two, or three sections.Two of those fans should be plenty... and only required during hot weather.I don't want the air to short circuit the route, if the air is coming from the bottom (like my design) it has no choice to sweep the whole thing before being evacuated, but if I install vents on the access door the air could come from the top of the door and miss the bottom part of the fridge. does that make any sens or am I over-thinking it?Anyways I forgot to mention one important thing, the access door is right next to the vehicle's gasoline inlet...I think the law says to be at least 36" away? by being on the bottom like this I'm adding distance between the air intake and the gas inlet, I will even add a baffle under the van to add separation.TakingThe5th wrote:There are current installations in RVs that do use a fan(s) to dissipate heat from the back of the unit. My installation uses a thermal switch to control the fan in the back.So you have the two big rear vents with a fan installed, and your fan only comes on when the thermal switch is triggered right?In my case I wouldn't have those two big vents, my fans would have to be triggered every time the fridge comes on, right? I didn't invent this design, I know people have been plugging PC fans somewhere behind the fridge DIY style, I just gotta figure out how and where to plug the wires.

Venting from the side wall would work fine... mine does, and so do hundreds of thousands of other rv's. And you could, theoretically, end up drawing trapped exhaust pipe heated air up thru the cabinet. But yes, the fuel filler is a logistics/safety issue, for sure. Any way you can install the fridge away from that area?

DIY 3 way refrigerator venting (drawing) | Good Sam Community

21 Replies

evy
Explorer
Jun 26, 2016
westend wrote:
How will I know if there's not enough air movement in the back of the fridge?
Fridge will not cool down to safe operational temperature.

Just to make sure I understand, you mean that I will decide if the inside of the fridge is cold enough to refrigerate the food? Using a thermometer for example.
westend
Explorer
Jun 25, 2016
How will I know if there's not enough air movement in the back of the fridge?
Fridge will not cool down to safe operational temperature.
evy
Explorer
Jun 25, 2016
How will I know if there's not enough air movement in the back of the fridge?
Is there a high temp warning light in the panel? An error code?
evy
Explorer
Jun 25, 2016
MrWizard wrote:
Buying new?
Why not forget the LP and buy a 12vdc powered compressor fridge
Like solar home and boats use Dan Foss DC powered variable speed compressor about 4 amps aka 48 Watts when running
No external venting required and way less power use, just need air circulation interior of cabinet and Van

Actually the pictures you see are from my installation so it's a bit late for going with your proposition :-/
Thanks anyway
MrWizard
Moderator
Jun 25, 2016
Buying new?
Why not forget the LP and buy a 12vdc powered compressor fridge
Like solar home and boats use Dan Foss DC powered variable speed compressor about 4 amps aka 48 Watts when running
No external venting required and way less power use, just need air circulation interior of cabinet and Van
evy
Explorer
Jun 25, 2016
So here's a quick update.

I have to add some baffles here and there, sheat metal around the lower opening,

The main concern is having my lower inlet 10" away from the fuel filler, the law says that it should be at 36"
So here's my two options :
Option no.1 : seal the lower vent so no air goes through and use it as an access door only, and only use only the bottom openings for the air inlet.
Option no.2 : add some sort of 12v time delay switch, set it to 15minutes, add a magnetic sensor (home alarm system type) to the fuel filler, so when you open the door to pour fuel in the fridge is automatically turned off, and it turns back on by itself 15minutes later or so. this way I could keep the lower inlet open for air movement as well as the bottom ones.
Now I don't know much about magnetic sensor and time delay switchs yet, maybe some one out there can help me out.
jrnymn7
Explorer
May 22, 2015
Yeah, with that short of a fridge, the side exhaust vent will work. My fridge is much taller, and a side vent was not possible (due to the curvature of the wall-to-roof area). The important thing is you include that "baffle" at the top to help direct air out. (see page 3 of old-biscuit's link). I'd still consider a roof vent though, if it's a viable option.
westend
Explorer
May 22, 2015
I'd try to get the intake air up from the bottom of chassis and as far away from the fuel filler as possible. Any flammable gas will tend to sink and possibly, pool in a confined space. The last thing you want is to pull flammable vapor into the fridge space.

Old-Biscuit probably has the ventilation nailed. If you install a top-mount vent, a fan probably wouldn't be necessary but many do actively push air to increase efficiency.
nineoaks2004
Explorer
May 22, 2015
jrnymn7 wrote:
Venting from the side wall would work fine... mine does, and so do hundreds of thousands of other rv's. And you could, theoretically, end up drawing trapped exhaust pipe heated air up thru the cabinet.

But yes, the fuel filler is a logistics/safety issue, for sure. Any way you can install the fridge away from that area?

Most Pop Ups vent out the side and mine looks almost like yours, I hook up two 110 v fans that I took out of Traffic signal Cabinets and installed a switch to turn them on,they run when the fridge is on in warmer weather and I have the option to turn them on in cooler weather when I notice the temp climbing in the reefer. Your design seems to look good and should work well
evy
Explorer
May 21, 2015
Old-Biscuit wrote:
Do you have the fridge installation manual for your model?

Follow the 'clearances' closely.

If installing lower vent bottom of it should be flush with floor. (Don't need that floor vent)
Then install a upper vent in side wall (just like lower one)

Bottom of top vent should be level with top of fridge.

There should NOT be any clearance between top of fridge and cabinet....Zero clearance otherwise you create a dead air space

HERE is some Ventilation Installation information.

Proper clearances -------better cooling

Thanks for the info!