I got curious about the relative performance of the compressor-type fridges (electric Engel, Norcold etc) and the absorption types (3 way, propane etc).
I went out and did a bunch of measurements in the 3 way fridge we have in our little trailer. I put in a thermocouple inside the empty fridge with an outside display and recorded that temp as a function of time, as well as the ambient temp in the trailer (should have also done the outside since the condenser is exposed to the outside air but oh well...). This since I really had no idea how fast this fridge would cool things down and how cold it would keep things under high ambient temps. Of course, measurements with an empty fridge does not tell the full story about how fast one could cool things down if they were placed hot in the fridge. Did not open the door during the measurements.
The fridge is a 1.5cuft inside volume (about 45qts). Dometic built-in.
Too much data to post here now, but the basic lesson seems to be the following:
- the mode used (12V, 110V, or propane) did not seem to make much difference as far as cooling .
- Generally speaking it takes about 2 hours to cool the inside down from about 70 F to freezing with ambient temps of the order of 80F.
- the lowest temp it could maintain at around 65F or so ambience was of the order of 25F. That was evening and early am. Have not checked in the middle of the night, but don't think it would go too much lower.
- at higher ambient temps, say 80F or more during the day, the fridge seems to be limited to maintaining temps around 32F.
So it seems that we are not talking here about technology that can do deep freezing during the day. Obviously, though, the big advantage of the propane mode is that you can run the thing for a month off a smallish tank vs a few days off 2 truck batteries (I guess). Admittedly, though, if you were to camp for an extended time with an Engel you could use a generator or turn on the truck every day. But then you need extra gas...
Now, I don't know much about portable compressor types a la Engel, but suspect they can probably go colder faster. This is based on some data I saw on the i-m-d site. But no idea if these are true in real life.
Sooo, anybody has any figures on how cold and how fast one can cool things down with a compressor fridge?
I went out and did a bunch of measurements in the 3 way fridge we have in our little trailer. I put in a thermocouple inside the empty fridge with an outside display and recorded that temp as a function of time, as well as the ambient temp in the trailer (should have also done the outside since the condenser is exposed to the outside air but oh well...). This since I really had no idea how fast this fridge would cool things down and how cold it would keep things under high ambient temps. Of course, measurements with an empty fridge does not tell the full story about how fast one could cool things down if they were placed hot in the fridge. Did not open the door during the measurements.
The fridge is a 1.5cuft inside volume (about 45qts). Dometic built-in.
Too much data to post here now, but the basic lesson seems to be the following:
- the mode used (12V, 110V, or propane) did not seem to make much difference as far as cooling .
- Generally speaking it takes about 2 hours to cool the inside down from about 70 F to freezing with ambient temps of the order of 80F.
- the lowest temp it could maintain at around 65F or so ambience was of the order of 25F. That was evening and early am. Have not checked in the middle of the night, but don't think it would go too much lower.
- at higher ambient temps, say 80F or more during the day, the fridge seems to be limited to maintaining temps around 32F.
So it seems that we are not talking here about technology that can do deep freezing during the day. Obviously, though, the big advantage of the propane mode is that you can run the thing for a month off a smallish tank vs a few days off 2 truck batteries (I guess). Admittedly, though, if you were to camp for an extended time with an Engel you could use a generator or turn on the truck every day. But then you need extra gas...
Now, I don't know much about portable compressor types a la Engel, but suspect they can probably go colder faster. This is based on some data I saw on the i-m-d site. But no idea if these are true in real life.
Sooo, anybody has any figures on how cold and how fast one can cool things down with a compressor fridge?