Improving Fridge Cooling

bob_nestor wrote:
First, absorption units do better on propane and 110v than they do on 12v. The 12v is only there to try an maintain temps while traveling.

Second, minimize putting warm things in, so limit the number of times and the length of time you have the unit open and try not to put a lot of things in at the same time that aren't already cooled down.

Third, they all work by transferring the heat to the outside via the cooling coils in the back of the unit. For most installations that uses just normal airflow over the coils - since hot air rises it brings in cooler air at the bottom and exits at the top. Units installed with a top roof vent work better than units with the top vent on the side. Most manufacturers don't follow the recommendations for clearances in the back where the coils are and usually allow too much space. Limiting the space to the recommendations using baffles and such helps with the airflow. Adding fans can help, but be careful. Just moving a lot of air may not be as effective as moving the right amount of air over the coils. Faster air can create a turbulent airflow and a laminar airflow is what you want for maximum heat transfer.

Finally, since the unit's performance is based on the ability to transfer the heat outside thru the coils, the temp difference between the air at the coils and the outside air is important. Try not to park your RV in such a way that the sun is heating the area where the refrigerator is located. And remember that at most the unit can probably create about a 40 degree F temp difference, so it will work better when the outside temps are around 70 than it will when the temps a pushing triple digits.

I cannot tell a lot of difference in performance on LP vs. 120VAC. I try to achieve laminar airflow by using the same amount of CFM at bottom of coils and at top (exhaust). Within reason, I'm not sure why having more air passing over the coils would be a negative issue.

Living in Texas, I sure need more than a 40 degree differential from the ambient outside temps. I've been able to achieve that at times but not always. Humidity seems to play a large role.

My previous trailer exited at the top, and required me removing the fridge and building new baffles. My new Grand Design trailer exits on the side of the slide, and looks as though they followed manufactures specs so I don't feel that's an issue.

I'm definitely going to add some fans but also looking at the ARP Fridge Defend system. I may use my muffin fans and not their squirrel cage type.

I have yet to determine if the add on fridge interior fans do that much.

Thanks for all the replys.