I have a Dometic (Waeco) CoolMatic CR-1110 Refrigerator
in my cabover truck camper. This refrigerator
is a compressor
style refrigerator. I was concerned that the compressor
was running too long in warmer temperatures to keep the fridge at a reasonable temperature (40 degrees).
I have a friend that has an Isotherm Cruise
CR 130 compressor style refrigerator Installed in a Sprinter van. I thought doing a comparison between the two would tell me how my Dometic stacked up with the Isotherm
Comparing both refrigerators:
1. They both have a Danfoss BD35F compressor.
2. The Isotherm is a little larger at 4.6 cubic foot and the Dometic is 3.8 cubic foot.
3. The Dometic is 6 months old and the Isotherm is 4 years old.
4. The way the Isotherm is designed the condenser coils are in closer proximity to the compressor (which gives off a lot of heat) than the Dometic
5. There are more condenser coils on the Dometic.
6. When each refrigerator was running, they were drawing approximately 4 amps
To do the testing, I did the following to both refrigerators:
1. I put two, one gallon ziplock bags full of water
in the refrigerator section and a one quart ziplock bag in the freezer
2. I ran both for 12 hours previous to gathering data.
3. I checked measurements on the compartments that the refrigerators were installed in and both exceeded the requirements provided by the manufacturer
The Dometic refrigerator interior
temperature was, freezer
section 13 degrees, refrigerator section 38 degrees. The outside ambient air temperature was 87 degrees. The compressor was cycling on and off and stayed on 31% of the time
The Isotherm refrigerator interior
temperature was, freezer section 18 degrees, refrigerator section 53 degrees. The outside ambient air temperature was 90 degrees. The compressor was on 100% of the time.
To be fair I was concerned that the cabinet enclosures might be different between the Dometic and Isotherm and affect the operation of the refrigerators so I decided to remove the Isotherm from its cabinet and do the same test with it in unrestricted airflow. (I did not test the Dometic out of its cabinet) The refrigerator interior temperature was, freezer section 13 degrees, refrigerator section 36 degrees. The outside ambient air temperature was 92 degrees. The compressor was on 100% of the time.
Conclusion: The Dometic was a clear winner in my test. It only ran 1/3 of the time and maintained an internal refrigerator section temperature that was 15 degrees lower than the Isotherm. Even when the Isotherm was outside of its cabinet it could only maintain a similar temperature as the Dometic yet it ran over 3 times longer.