DIY 3 way refrigerator venting (drawing)

[evy]

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!

[jrnymn7]

I would also seriously consider going with a proper rooftop mounted vent. You do not want to choke things off with that small 3 1/4" x 10" goose neck; fan or no fan. Build an insulated chase wall, the full width of the fridge, up behind the food cabinet, and curve inwards towards the centre of the van, until you're far enough in to accommodate the vent. (this is exactly what I did, and it works fine). It's better to vent out the top, rather than the side, as a good stiff breeze could easily force air back down into the chimney. This is much less likely to happen if roof vented. (and no, installing a side wall goose neck with a back draft damper is not an option in this case. You need as little obstruction/restriction as possible)

[evy]

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?

Believe me if there was a way to simply put vents I would've gone that rout, but I have so little space (Ford extended E250) There's not a lot of options...

Here's a look at my floor plan design, it has not been updated in a while, since I bought the van I have realized that there are many issues/conflict that I have to re-think, for example : the furnace and water heater, and I will switch the refrigerator's position with the bathroom (behind the driver's seat) because of a beam I can't cut in the outside wall...

[jrnymn7]

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?

[evy]

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 vent

They 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.

[TakingThe5th]

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]

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.

[jrnymn7]

Why not make that 12" x 12" access door a vent, instead? These work well, and are screened:

soffit vent

They 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.