Hi,I was forced to park in a manner where I thought it prudent to turn the fridge off.I've often seen folks claim the fridge is cool after many hours. This appears to be apocryphal.The fridge:Dometic Royale Tri-Fuel Fridge (6 cu. ft.)The conditions:I parked with the fridge on the north side so it was not in direct sunlight. Ambient temperature was 22 C (71.6 f). There was mixed cloud, and it was 1 p.m.Interior of the RV was 22 c (71.6 f)Interior of the fridge was 2.7 c (37 f), measured on the top shelf of the door.After 2 hours the interior of the fridge had risen to 6.4 c (43.5 f)The drain tube is properly set up with a dip in it to prevent air infiltration.As I knew I would have power later, when I restarted the fridge I did it on 120 volts via the inverter. Input from alternator and solar to the fridge were about 25 amps. I drove for about 2 hours and the batteries were quite happy to start recharging at 24 amps once I had shore power. While the fridge was playing catch up duty cycle appear to be 100%.The fridge was not opened and the interior was still at 4.5 c (40.1 f) after the two hours of run time. It is equipped with a dual interior fan, and dual "chimney" fans that sucks air over the exterior coils. The unit has the ARP control installed. (I love having that btw--no more driving in endless circles in parking lots to get perfectly level!)My conclusion is that the fridge can be shut down for only one hour from a safe food storage point of view.

Did you open the door to measure the temperature, or do you have one of those outside thermometer?3.7C raise in 2 hr is not bad IMHO. Bare in mind that with fridge off it is the food who is the source of cold, meaning the internal walls will be warmer than the food itself. I would more worry about freezer side as defrost food should not be frozen again.

That may be why many people, me included, never shut off the fridge.

"The fridge was not opened"Since the recommended number for food storage is a minimum of 4.5 c (40 f) and the interior was above that number for at least 2 hours (and more probably 3), it is an issue.The freezer, on the other hand, has no "direct connection to the outside world" via the drain tube, so it will not rise in temperature nearly so quickly.Kayteg1 wrote:Did you open the door to measure the temperature, or do you have one of those outside thermometer?3.7C raise in 2 hr is not bad IMHO. Bare in mind that with fridge off it is the food who is the source of cold, meaning the internal walls will be warmer than the food itself. I would more worry about freezer side as defrost food should not be frozen again.

My experience is contrary to yours - I keep an external remote thermometer in my fridge and I can turn the power off and it will maintain temp for many hours and go for at least 8 hours B4 temp gets high enough to raise any concerns. Maybe one or both of us have lousy temp gauges? I suspect the amt of cold food/thermal mass in a fridge has a significant impact.

Don, I think what you see is not uncommon, though yours seems to be worse than average. Rarely turn mine off after I've settled down on the camp, so don't keep a wireless thermometer. So, without measuring accurately (or at all) - temperature rises by 2C (4F) or more in less than 4 hours at temps in upper 20s (82-84F). I know this because it's cycling 100% for some time after that (for at least one hour), and by how much "pop" I get when opening a soda bottle. 6-something cu.ft Norcold. Opening the door at 84F is a killer, even when it's running. I think the problem is that fridges under 7 cu.ft are very shallow inside, front to back. Have never observed anything even close on deeper compressor fridges.

how long does the fridge stay cool? | Good Sam Community

ksg5000
Explorer
May 20, 2016
pianotuna wrote:
Hi ksg,

Where do you keep the sensor (inside the fridge)? What make and model of fridge do you have?

I keep the sensor on top shelf of fridge. Not sure of model - std Dometic that is about 8 yrs old. I suspect the variance is do to thermal mass because when I travel my fridge tends to be full of "pre cooled" stuff - might make a difference.
pianotuna
Nomad III
May 20, 2016
Hi CJ,

Here is a list of what was inside:

1 liter of milk, 1.5 liters of water, 8 eggs, 1 lb of carrots, 1/2 loaf of bread, 1 liter of vinegar, 1 pound of butter, 1 pound of margarine, .3 liters of mustard, 1 pound of cheddar cheese, 1 liter of jam/jelly/honey/peanut butter (the little packages from restaurants), 1 box of baking soda, 1 liter of oil, 1 liter of pomegranate juice, one jar of green relish, l liter of maple syrup, 1 tin of ginger ale and one bottle of Worcestershire sauce.

The freezer, on the other hand, was pretty much fully packed.
CJW8
Explorer
May 20, 2016
You left out one important piece of date. How much stuff was in the fridge?
If it is jammed full and everything is cooled down it will stay cold longer than if it is only half full. The more cold thermal mass pecked inside, the longer it will retain the cold.
2_many_2
Explorer III
May 20, 2016
turbojimmy wrote:
Am I the only one that had to google "apocryphal"?

I didn't even try :h :B
time2roll
Nomad
May 20, 2016
I have left the milk out on the table for an hour. Still good for the week.
One 8 hour drive is not going to spoil all the food. Every day would be a different story.
turbojimmy
Explorer
May 20, 2016
Am I the only one that had to google "apocryphal"?
Almot
Explorer III
May 19, 2016
Old-Biscuit wrote:
Measurement of 'contents' is correct method to test cooling temp (probe/thermometer in container of water)

Yes. This is what I did to establish the optimal position of the switch warm-cooler-cold. Thermometer in glass of water. Doesn't even have to be wireless - inertia of water will let you take measurements while opening the door.

But... Don asked "how long".

40F at the door means that it is few degrees cooler inside - where it matters more. And, while it is cooler inside, it also warms up faster there, because the rate of warming up is proportional to temperature differential btw cold items and warm ambient.

So... repeat the experiment with probe deeper inside.
mike-uswest
Explorer II
May 19, 2016
In the summer we are looking at 90-105 degrees outside temp, often higher in the trailer, and we are happy to keep it below 45 degrees in the fridge.

Mike
Old-Biscuit
Explorer III
May 19, 2016
pianotuna wrote:
Hi Old,

I'm measuring air temperature on the top door rack.

Seals appear to be in good shape, and will hold a sheet of paper in place.

Air temp is NOT the correct measurement of 'cooling' in absorption fridge.

Food section fin temp is what is measured for thermostat controls.
Fin temp runs 10*F lower than actual compartment temps
Measurement of 'contents' is correct method to test cooling temp (probe/thermometer in container of water)
Almot
Explorer III
May 19, 2016
I wonder who needs Yugo mini in a country with average 2-3 children per family :)... Sorry for distraction.

Forum Discussion

how long does the fridge stay cool?

About Technical Issues

Related Content

Fridge & Freezer Not Cooling

Keeping cool while boondocking

Amish Cooling Unit

Cool Ford truck

Heating and cooling