Baffle for exterior fridge coils

[austinado16]

Thought some of you might like to see the simple baffle I made for the Dometic RM2190 on my Starcraft Nova.  Learned about this from a really good RV fridge website and it took just a few minutes to make and install.  Now all the air that is convected up through the lower louvered fridge door has to go past the big metal coils.

['tiredTeacher]

Now all the air that is convected up through the lower louvered fridge door has to go past the big metal coils.

Clean work. My only thought is how much you have restricted the air volume available to the upper compartment. Your installation would be very effective if there were a fan pulling the air up, but since you are relying on simple convection, decreasing the volume may offset the gain in direction.
I put my baffle in the upper compartment to direct the flow higher up into the compartment, hence over the coils without reducing volume.

[austinado16]

I'm no fluid dynamics expert, but I think there's a Law about if you speed up the velocity of the flow, you increase volume.  Sort of like putting velocity stacks on carburetors as opposed to having them just breathing from their big end opening.

I'm assuming that since the convective process is moving only a certain volume of air up the back of the fridge, that by containing that volume in a tighter space, I'll get more air speed, more heat transfer off the coils, and possibly more air volume as a result.  

I guess the other part of the baffling trick is that all the air is forced over the coils rather than allowing some of it to just go around them in the 2-1/2" air gap that was there originally.

[mike4947]

Very nice mod and you are correct that the less air that goes around the coil than over it the more efficient the fridge will be.
Unless you have a upper vent mounted to low so it generates a pocket of hot air trapped at the top of the fridge compartment I'd say you're good until at leaast the low 90's or better.
Another "trick" is to put the fridge side of the trailer in the shade. Direct sun even on the outside panel can reduce the efficiency of the fridge.

[austinado16]

Nice idea about having the fridge side in the shade.  I hadn't thought of that.

The upper louvered panel is as high as it can go, so I'm probably about as efficient as I can get without going to fans and/or a heavy aluminum panel as a baffle right up the back of the coils to act like a heat sink as well as a venturi.

[Scott Nelson]

The literature with my fridge clearly states taht it is supposd to have a baffle.  Coleman installed one originally, but it appears to have been made out of that stupid pressboard junk and probably only lasted until it was off the lot at the assembly plant.

Just FYI