Dometic Fridge Food Safety

[MCtree]

While on a road-trip, I noticed that some BBQ that I had put in my fridge was still luke-warm after being in there for 6 hours.
For food safety reasons, this troubled me since the FDA says not to store food from 40F to 140F.

And to be clear, this was BBQ left-overs. So it's not like it was hot when I put it in the fridge. I would guess it had been on the table for an hour, so it was likely mildly warm when I put in the the Dometic.

So I ran a test yesterday on my Dometic CFX3_95.

I filled both the large section and the smaller section with tupperware filled with ice water so that both internal compartments in the cooler were about 75% filled.
I set the large side to 10F and the smaller side to 33F (which is how I normally employ the fridge).

I put a thermometer on the very bottom of the smaller compartment. I put another one midway up in the compartment - so it was resting on the internal ledge in that compartment. And then I put a thermometer on top of a piece of tupperware that was about an inch below the closed lid of the compartment.

The table below is of the results:

Edit: cutting and pasting an Excel table gave something unreadable when I published it.
So I'm replacing with a screen-shot of the table:

Note that the temps on the top level never get into the "safe zone."

 

[MCtree]

My Take-away from this, not terribly scientifically rigorous test, is that the general temps inside the fridge are mostly reliable as per what the app says.
And that the fridge does a good job hitting and maintaining target temperatures – but this is for the center of the compartment.

However, one should be cautious putting sensitive food near the top of the fridge. Like I wouldn’t put fish up there.

Also, it might not be a bad idea to set the fridge compartment to 30 or something and put items that you wouldn’t mind freezing on the lowest level so the entire compartment would be food-safe.

Though, I should say that for several years I have put BBQ on that top level in just the manner that alarmed me and I have never gotten sick. But perhaps I have just gotten lucky – so far.

 

[UPR LC]

Interesting. I do usually place items that need to remain cold toward the bottom of my fridge. I guess in the back of my mind the top would remain warmer. This proves that to be correct. Thanks for putting in the effort to record it!

 

[MCtree]

Ha! Yeah, I guess it is somewhat of an expected result.
I guess I was hoping for more homogeneity of temperature inside the compartment.
Not the stark division I saw.

And to be clear, the cooler was in my LC with the rear hatch open and the vehicle in the shade. And the external temps ranged from 65 to 69.

 

[doru]

People in US are far too scared about getting sick. I honestly did not expect you to get sick with those temperatures at the top.
Food safety is not just about temperatures but also how you cook and how you handle the food before and after cooking.
Besides all that a normal person (not under stress from injuries or illnesses) has enough natural resistance even for the modern cocoon people.
I'm not saying to be reckless but not over concerned either.

Nevertheless, your unscientific study as you call it is very valuable for when you do need those low temps, like that ice cream in solid form at your destination Thanks for contributing!

 

[hoser]

Food I put in the top area: chocolate, hard cheese, lettuce, tomatoes, bread/muffins.... and food that would be normally okay at room temperature but would get demolished in a parked vehicle baking in the sun. Bread also seems to do okay in a traditional cooler, with no ice. I also use reflective shades on the windows in the trunk area.

 

[coleAK]

We now have three cfx3 95L that my daughter uses at a commercial capacity for her business. we have separate internal real time temperature monitors. We keep the fridges set to 34F in order to keep all contents safely under the 39F cut off the food inspectors want to see. And even with a fridge full of raw meat it uniformly keeps at the approperate temps. However last summer we had a stretch where it was hot (well south central Alaska hot) temps in the 72-76F and it couldn’t keep up, we had to put gel freezer packs on top of the meat.

That said the dometics perform amazing and we have 5 total (also two 55L CFX3).

 

[FrazzledHunter]

Would opening and closing the lid to take measurements affect the results? Especially at the top?

 

[MCtree]

Would opening and closing the lid to take measurements affect the results? Especially at the top?

Yeah. I would certainly think so.

I didn’t open the lids at all during the 8.5 hours of testing.
I would think that opening it during the test would only increase the temperature differential between the mid area and the top area.

 

[MCtree]

We now have three cfx3 95L that my daughter uses at a commercial capacity for her business. we have separate internal real time temperature monitors. We keep the fridges set to 34F in order to keep all contents safely under the 39F cut off the food inspectors want to see. And even with a fridge full of raw meat it uniformly keeps at the approperate temps. However last summer we had a stretch where it was hot (well south central Alaska hot) temps in the 72-76F and it couldn’t keep up, we had to put gel freezer packs on top of the meat.

That said the dometics perform amazing and we have 5 total (also two 55L CFX3).

Interesting. I wonder why you see different results than what my one test showed.
Where in the compartment is your real time temperature monitor?
If it’s at the mid-point of the depth of the compartment, perhaps the meat at the top is above 40F?
(Though, certainly the external temp around the dometic would be a large factor and likely AK is cooler than the 68 we had here in Houston yesterday.)

Though you did say “uniformly.” So perhaps the temp monitor takes readings at several depths?

One thing I am contemplating is if I somehow blocked airflow. Perhaps if one positions the items in the cooler well, the temperatures at different heights are more uniform?
Like a convection oven.

 

[FrazzledHunter]

Yeah. I would certainly think so.

I didn’t open the lids at all during the 8.5 hours of testing.
I would think that opening it during the test would only increase the temperature differential between the mid area and the top area.

OH!!! Sorry. I assumed you had thermometers that required opening/reading to get a measurement.

 

[coleAK]

Interesting. I wonder why you see different results than what my one test showed.
Where in the compartment is your real time temperature monitor?
If it’s at the mid-point of the depth of the compartment, perhaps the meat at the top is above 40F?
(Though, certainly the external temp around the dometic would be a large factor and likely AK is cooler than the 68 we had here in Houston yesterday.)

Though you did say “uniformly.” So perhaps the temp monitor takes readings at several depths?

One thing I am contemplating is if I somehow blocked airflow. Perhaps if one positions the items in the cooler well, the temperatures at different heights are more uniform?
Like a convection oven.

My temp monitors have to go on the top of the food per the food inspectors. So my fridges are usually full and the sensor sits under the lid.

 

[MCtree]

OH!!! Sorry. I assumed you had thermometers that required opening/reading to get a measurement.
View attachment 4102516

I used three of these:
$14 each! They record the temp and you can download it later.

As an aside, I might have an issue. I now have 6 of them. I keep finding new uses for them.

I do love them for camping in cold weather so I can know just how cold it got the previous night as I shivered in my tent.
And then I buy another because I’m curious as to how the temp in my tent differed from the external temperature.

 

[MCtree]

My temp monitors have to go on the top of the food per the food inspectors. So my fridges are usually full and the sensor sits under the lid.

Interesting.
I wonder why you see different results than I do.
Perhaps it’s colder external temps?
Or maybe I didn’t wait long enough. Note that the temp at the top of my freezer was still decreasing at the end of my test.

Also… is the meat at the bottom of the dometic frozen?

Also…. I take it you are using both the smaller side and the larger side for this meat storage?
I wonder if we are seeing different results because we are using different sides of the fridge.

 

[hoser]

I will also add, you have to be careful and understand where the temperature probes are located. If you throw a piece of frozen meat or ice block on top of the temp sensor, it will throw off the rest of the fridge for hours..... maybe days.

 

[peesalot]

put a light in the fridge at nigt or in a dark out room, close fridge, see if you can see lite around lid seal, i used this method to find a slight gap along the hinge side of my engel, new gasket, reduced cycling and doesnt have the warm layer at top.

 

[UPR LC]

put a light in the fridge at nigt or in a dark out room, close fridge, see if you can see lite around lid seal, i used this method to find a slight gap along the hinge side of my engel, new gasket, reduced cycling and doesnt have the warm layer at top.

Good call!

 

[MCtree]

put a light in the fridge at nigt or in a dark out room, close fridge, see if you can see lite around lid seal, i used this method to find a slight gap along the hinge side of my engel, new gasket, reduced cycling and doesnt have the warm layer at top.

This is a good idea!
I just ran this test with two pretty bright lights placed inside the compartment and couldn’t see any light escaping from inside the fridge.

It’s a shame. I was hoping this would be my issue.
And in inspecting the gasket, it looks to be in good condition.

I’m thinking about re-running the test with the thermometers but with some sort of insulation on top of the lid.
But I suspect a blanket wouldn’t move the needle much.
So I’m open to other suggestions if anybody has one.

 

[peesalot]

Curious, have you run a temp test on both 12V & 110V ? I had an old Engel that would cycle 2 minutes faster on 12V, cooled fine but I tested the cycle times on a hot arse day, fridge under patio awning, 9 min 12V 12 to 14 on 110V, temps were good, figured it was good to go, put in truck, loaded, went to leave in morning, dead Batt, seems as though although working, it was drawing absurd 8 amps, took the little dealio out of the cig lighter and that engel still runs fine.
Curious what a 110V test shows.

 

[MCtree]

Curious, have you run a temp test on both 12V & 110V ? I had an old Engel that would cycle 2 minutes faster on 12V, cooled fine but I tested the cycle times on a hot arse day, fridge under patio awning, 9 min 12V 12 to 14 on 110V, temps were good, figured it was good to go, put in truck, loaded, went to leave in morning, dead Batt, seems as though although working, it was drawing absurd 8 amps, took the little dealio out of the cig lighter and that engel still runs fine.
Curious what a 110V test shows.

Hmmm. I’m not sure if this matches my problem.
I’m running the fridge from the 12V output from an Ecoflow delta 2.

In looking at the temperature chart from the lowest thermometer in my test, I believe the compressor runs for 15 min and then sits idle for 25 min and before kicking back on again.

And also note that it’s not like the fridge wasn’t getting down to proper temps. The lowest and middle thermometers were pretty much on target.
It was just the thermometer up close to the lid that remained too warm for my tastes.

Or am I thinking about it wrong?