Does Your Refrigerator Maintain Safe Food Temperatures?

[TucsonJim]

I have published this experiment in a few different locations. But I thought it was important to share the information on this new forum. When you travel, do you keep your refrigerator powered on during hot temperatures? If not, how do you keep your food from becoming tainted with bacteria? The results of the attached experiment show that on a hot summer day, the temperature in your refrigerator can become excessive in a very short time frame. And even with "blue ice" placed in the refrigerator, the temperature can still become unsafe.

Many people are against running with the propane turned on. But if you don't wish to do so, there are alternatives such as running your refrigerator on electric via an inverter. Another option would be to move your food to an ice chest which is better designed to maintain the temperature. What are your thoughts?

2018 RV Refrigerator Study.pdf

[Paul & Deb]

Good work Jim. Your findings do not surprise me at all which is why I've run all my RVs with the propane fridge on at all times.

[kevinpo]

Hello,
I have also run my fridge on propane the last 35 years or so while traveling (the thought of warm beer scares me as much as bacteria)

Regards,
Kevin

[TucsonJim]

Hello,
I have also run my fridge on propane the last 35 years or so while traveling (the thought of warm beer scares me as much as bacteria)

Regards,
Kevin

LOL the warm beer comment. When we first got our 297, I put my beer in the little outside refrigerator and set it to the coldest setting. The next day I came out and opened one and the beer was frozen. It grew the strangest stalagmite of beer ice I've ever seen. Now, I set that little reefer on 2 (out of 10) and my beer is right at 33°.

[Paul & Deb]

LOL the warm beer comment. When we first got our 297, I put my beer in the little outside refrigerator and set it to the coldest setting. The next day I came out and opened one and the beer was frozen. It grew the strangest stalagmite of beer ice I've ever seen. Now, I set that little reefer on 2 (out of 10) and my beer is right at 33°.

in this regard Jim, do you now travel with your inverter on so this little beverage fridge stays on?

[TucsonJim]

in this regard Jim, do you now travel with your inverter on so this little beverage fridge stays on?

No, my project when I get back from our summer trips is to figure out how to install a transfer switch and change my wiring so I can run the inverter while mobile.

[Guest]

Such a valuable and well organized study. Really nice work Jim.

I also travel with the propane and battery turned on.

[FatTire]

I don't need convincing that my fridge should stay powered on during travel - in my case via propane. However, my fridge doesn't maintain food safe temps in the summer even when powered on. I have a 2018 Reflection 303RLS with a Dometic RM1350SLMX and it struggles in the heat. I have added an additional fan in the lower compartment blowing up, and it already has the plywood chimney in the upper vent and 4 cooling fans. I had it checked on a recent service trip at the dealer and they stated it was working fine. I'm actually considering replacing it with a residential unit, but have no idea what that involves. Hoping to get support on this issue from either Grand Design, or members here who are experiencing the same issue.

[TENN22]

I don't need convincing that my fridge should stay powered on during travel - in my case via propane. However, my fridge doesn't maintain food safe temps in the summer even when powered on. I have a 2018 Reflection 303RLS with a Dometic RM1350SLMX and it struggles in the heat. I have added an additional fan in the lower compartment blowing up, and it already has the plywood chimney in the upper vent and 4 cooling fans. I had it checked on a recent service trip at the dealer and they stated it was working fine. I'm actually considering replacing it with a residential unit, but have no idea what that involves. Hoping to get support on this issue from either Grand Design, or members here who are experiencing the same issue.

The problem with all of the Norcold and Dometic refer is they cannot vent the heat due to being installed in a slide out. Remember the days of refers being vented through the roof? To compensate for this problem, the refer manufacturers have started adding fans (some add one, some add three) to back side of the fridge to pull air in the bottom vent and push it out the top vent. In my most recent experience the problem is these fans are thermostat controlled, and the thermostat is a position sensor mounted on the dissipation fins at the top of my unit. In my case the thermostat is hard set to 130 degrees before it will turn the fans on. Being mounted on the outside edge of the fins it will rarely ever kick on. The tube leading to the fins will reach 140- 150 degrees (tested with IR thermometer) but the outside fins stay around 115 or 120. I was told the thermostats used to be hard set at 100 but somewhere along the lines they stopped making them and now all manufactures have are the 130 degree ones.

So....the fix for me was to bypass the thermostat so that my 3 fans would run whenever the fridge was powered on. Voila! problem solved, went from a 9 setting on fridge and barely staying at 40 degrees inside the box, to a setting of 4 and maintaining 33 degrees inside the fridge.

I am told that if we camped in below freezing temps for long periods of time, this might caused my refer to get too cold, I will take my chances for now. IF that becomes a problem, MotoCamper pointed me in the direction of programmable thermostat switches on Amazon for $20 or so, and I will make that switch if needed.

[FatTire]

So how do you bypass the thermostat? I don't recall seeing anything attached to my fins - even have a picture of them. Will take a look and check temps with my laser thermometer.

[TENN22]

I will attempt to upload a picture. The picture is taken from the very top vent looking in towards the left and down. The two red wires are connected to the "button" thermometer that mounted to my fins. Just remove those two wires and jumper together. If your refer is powered on then you should hear these fans kick on and feel some air moving. You may have to remove the entire upper vent cover (approximately 10 screws) and reseal with silicone. The tube against the wall is where I took the IR reading of over 140 degrees. Ideally that is where the thermo should be placed according to the RV tech that helped me with this.

[Country Campers]

I am interested in this modification as well. TENN22 , could you post some more info or picks please?

Brian

[Rodeotexas]

On a recent trip to West Texas, our 7.0 CF non-residential Dometic refrigerator was loaded with prechilled items, plus a 20 lb bag of ice in the freezer.
The inside of the refrig we have a circulating fan.
Previously I retrofitted three computer fans to bring in air and exhaust the hot air; one to bring in, two to exhaust.
We left at 7AM, refrig. temp was 34 degrees, outside temp was 78F. Ran the refrig on propane while traveling. When we arrived at the campsite the refrig was at 48 degrees, outside temp was 90F.
We stayed a week in the Davis Mountains and I watched the refrig temp fluctuate during the day time from 42F to 52F, with outside temps ranging from 92 to 96F.
Only late at night when the outside temp cooled down to 66 to 68F did the refrig temp get down to a "safe temp" of 34 to 36F.
At the campsite, running on propane or electric did not seem to make a difference. Trailer was perfectly level and the trailer side with the refrig was shaded at all times.
RV refrig manufactures need to come up with a better operating system.

[KenBeccard]

Rodeotexas describes pretty much what I see with the same Dometic refrigerator. I can't maintain reasonable temps in hot weather. It'll cool down at night but can't manage the summer daytime heat.

[Guest]

The Norcold in my Imagine 2600RB works great where its on the awning side and vents through the roof. Looks like exposure and airflow can be limiting factors in efficiency. I have had my fridge get warm when traveling once in high winds where it was not staying lit?

[Country Campers]

The Norcold in my Imagine 2600RB works great where its on the awning side and vents through the roof. Looks like exposure and airflow can be limiting factors in efficiency. I have had my fridge get warm when traveling once in high winds where it was not staying lit?

Jim

The vent thru the roof is definitely a huge plus. I am not fond of the side vents. I think I will be trailer shopping or making some serious mods to help with the cooling issues.

Brian