Improving Fridge Cooling

[pulpwood007]

I did a search and read some of the posts regarding modifications to RV refrigerators. Seems like there are several ways to improve cooling, and some that don't work so well.

I would like to hear any about modifications that you have made to to your Dometic or Norcold fridge that improved the cooling in hot weather. Especially how many degrees you were able to drop the temps to.

[bgum]

Rig came from manuf with a fan in the top side vent. I added a fan in the bottom side vent aimed up directly on the coils. I also put a small battery operated fan on the bottom shelf inside the refer. Between the three it now cools even with sun shining on that side. I can turn both fans on or off as each has its own switch. I don't know how the temperature is but it is plenty cold. We camp in 90-100 degree temp with high humidity.

[2oldman]

Other than parking with fridge on the north side, not much. But I certainly do run air when it's hot out, if that helps.

My Dometic seems to cool just fine regardless of the temperature.

[bob_nestor]

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.

[cooldavidt]

Mitch- as an aside do you find it is better to use propane vs electricity?
I know there are many variables. Just your gut feel.

I can run my hot water on either. I have used electricity. No moving parts for starters.

David

[Lwiddis]

So if a modification or fan “only” improves fridge temp by two or three degrees that is “some that don't work so well?”

[BFL13]

First thing is make sure yours is installed correctly with a baffle at the back so the air coming up from the lower vent heading for the roof vent has to go close by the back of the fridge.

[MitchF150]

Do you use propane or electric or a combo of both?
Does the fridge have a roof vent or is it in a slide and have a side vent?
What temps are you seeing now?
How hot is it where you are running it?
Have kids that open/close the door all day?

In my case, my new trailer has the fridge in the slide, so it vents out the side of the slide.

First time I ran it, I felt how hot it was in that upper vent and was surprised at how hot it really was.

I let the fridge cool down (this was all done with propane) and it cooled down fine and got to around 40* and the freezer was frozen.

But, it was only around 70* outside, and I do go to hotter places during the summer camping run.

I got this dual fan setup for it and once I set it up, it pushes out the hot air and works very well in moving the air thru the vents.


Also, if it's possible to park the side of the rig where the fridge is on the shade side of the sun in the heat of the day, that helps too. But, of course, that's not usually an option depending on your site.

I noticed that you can feel the heat pushing out of the upper vent with the fans running, compared to them not running.

Temps in the fridge will get to 38* and colder, if left alone for awhile easily now and recover a lot faster when you do open it up. I always run the fridge on propane during the day and will switch to 120v overnight when it cools down and no one is opening the fridge all day..

I have the slide temp thing inside the fridge slide all the way to the top (coldest setting) and those fans run anytime the fridge is cooling, on propane or electric.

It's very quiet and runs on 12v, so even during transit, which I do keep the fridge running on propane, it can run.

Just what works for me and my setup. Good luck! Mitch