Dometic 8501 3 way fridge performance.
Submitted: Monday, Mar 19, 2018 at 20:50
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Olympic
I have often noticed that people are keen to know the performance of 3 way fridge & info is very limited.
I fitted a brand new Dometic 8501 into my caravan on 17/3/18. The weather was 33deg, extreme winds, & bush fires 15km away.
I used 2 Fluke meters to record temps. ($300 ea)
I started with 1/2 lt of water in freezer & 1 lt water in fridge. Water temp was 32deg.
The temps recorded were AIR temp. Fridge on 240volt.
Start up. Fridge...27.0....freezer....26.9
1 hr later,.............19.3..................... 2.5
next hr..................12.8.....................-4.2
next hr...................4.4.....................-13.2
Total temp drop.....22.5...................40.1.
The climate rating of the fridge is ST, I fully insulated it with 3.5R insulwool & packed up the spacing behind to have a gap of 40mm between the wall & burner cover per installation instructions
I am very happy with results & hope the information is helpful.
Reply By: Mick O - Monday, Mar 19, 2018 at 21:50
Monday, Mar 19, 2018 at 21:50
Olympic, are you going to complete the
test with the fridge running on gas and then on 12 volt DC?
For any
test to be of value, it needs to comprehensive
test all aspects of operation.
I'd be keen to see the gas and 12DC volt figures from start up under the same or similar conditions. AC power is always going to provide the best initial operation.
It would also further validate your insulation of the unit. Will look forward to any further reports.
Cheers
Mick
AnswerID:
617704
Follow Up By: Olympic - Monday, Mar 19, 2018 at 22:05
Monday, Mar 19, 2018 at 22:05
Mick, I did do a short
test on gas the next day & it was much better, but in all fairness, the day was cooler, 20deg. I will do a proper
test on Thursday when the weather is supposed to be 29deg, I don't see the need to do a
test on 12 volt as there are too many variants in cable length, cable size, voltage drop & after all it's only used for travelling when the fridge is already cold.
FollowupID:
889464
Follow Up By: Member - Phil G (SA) - Monday, Mar 19, 2018 at 22:34
Monday, Mar 19, 2018 at 22:34
Good points Mick. Performance on 12V on a hot day is usually the downfall of 3-way fridges.
But in all fairness, I think the 3way fridges in the caravans have improved and these days it is my preferred option when stationary out in the bush. Much easier to run a fridge that goes for 2 weeks on a cylinder of gas than it is to weigh up the camper or van with extra batteries and solar panels and "smart "chargers.
But nothing beats a compressor fridge in the heat up north.
FollowupID:
889465
Follow Up By: bobsabobsa - Tuesday, Mar 20, 2018 at 11:23
Tuesday, Mar 20, 2018 at 11:23
I Find gas is better than 240 volt as
well , good result
FollowupID:
889475
Follow Up By: Member - Bigfish - Tuesday, Mar 20, 2018 at 13:04
Tuesday, Mar 20, 2018 at 13:04
Mate has one in his van. Only uses it on gas when stopped up. He says it is just ridiculous to use on 12 volt because of the power consumption. As he said...great on gas or even 240 volt. 12 volt for when towing as you stated. He,s happy with the way it performs though.
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889478
Follow Up By: Mick O - Tuesday, Mar 20, 2018 at 15:17
Tuesday, Mar 20, 2018 at 15:17
I'm interested in Olympics work as we have the three way in the Ulti and ours is generally on gas when static and 12V when traveling. Very rare that we get the luxury of AC power. I'd be keen to see the gas figures as a comparison as I may be able to increase the efficiency of
mine by looking at the insulation properties. The other benefit in Olympics work for me is I can possible draw a comparison between a 12 year old Dometic 3 way of similar size (
mine) and the insulation and cooling properties of a new fridge (Olympics).
Good work Olympic and thanks.
Mick
FollowupID:
889483
Follow Up By: Member -Pinko (NSW) - Tuesday, Mar 20, 2018 at 16:18
Tuesday, Mar 20, 2018 at 16:18
I have a Dometic RM2356 in my camper and when mobile I use either 240v. through a small inverter or 12v .
There is no voltage drop using an inverter to the 240v element and temp stays pretty
well constant
FollowupID:
889487
Reply By: Olympic - Thursday, Mar 22, 2018 at 20:13
Thursday, Mar 22, 2018 at 20:13
Did a
test with the fridge today on gas. Temp was 29.5 deg, & water was same as last
test. Results were very similar, but I will
check the gas regulator tomorrow as I felt that the gas was roaring a bit much, & a lot of heat generated. 11in water pressure is what is required. I will do a
test on 12 volt tomorrow as it is going to be a hot day.
Start up...Fridge...24.8....Freezer.24.9.
1 hr later...............19.8................. 3.3
next hr..................15.3.................-4.8
next hr...................4.9.................-14.0.
Total temp drop....20.0.................38.6.
Going by the above comparison, 240 v is slightly better, although will
test gas pressure & post with 12volt results tomorrow
AnswerID:
617767