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08-03-2017, 08:59 AM
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#2
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Senior Member
Trailer: 1996 Casita Freedom Deluxe 17 ft
Posts: 454
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Absorption sounds a lot like the ammonia cycle refrigerator that is standard in a lot of our trailers, except only using electricity instead of the propane option.
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08-03-2017, 09:25 AM
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#3
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Member
Name: John
Trailer: Sold 2017 Casita SD
North Carolina
Posts: 41
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solid state refrigerator
Peltier modules are only around 5% efficient, some as high as 10% and low as 2%. Also they usually only cool about 36 °F below ambient temperature, so don't expect 30deg in the fridge when its 90deg outside.
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08-03-2017, 09:47 AM
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#4
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Senior Member
Name: Clif
Trailer: 08 Weiscraft Little Joe 14 Subaru Outback 2.5i CVT
Louisiana
Posts: 754
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Quote:
Originally Posted by Terry G
Absorption sounds a lot like the ammonia cycle refrigerator that is standard in a lot of our trailers, except only using electricity instead of the propane option.
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To clarify; absorption refrigeration is the same as what you are calling the ammonia cycle. They may use AC, DC or propane as a heat source and some can use any of the three; only one at a time of course.
As many of us on this forum have discovered, installation with proper ventilation is as important as having a properly functioning unit. The fridge can only remove heat from the box if the condenser coils can dissipate heat to the ambient air. And of course, ambient air temperature has a direct effect on heat dissipation, regardless of proper air flow.
Good luck in the search.
__________________
Clif
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08-03-2017, 09:50 AM
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#5
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Senior Member
Name: Charles
Trailer: Scamp 16
Ohio
Posts: 295
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It is absorbing heat and moving heat from one place to another.
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08-03-2017, 11:31 AM
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#6
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Senior Member
Name: John
Trailer: '71 Boler, '87 Play-Mor II
Deep South
Posts: 1,261
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Quote:
Originally Posted by The Minimalist
To clarify; absorption refrigeration is the same as what you are calling the ammonia cycle. They may use AC, DC or propane as a heat source and some can use any of the three; only one at a time of course.
As many of us on this forum have discovered, installation with proper ventilation is as important as having a properly functioning unit. The fridge can only remove heat from the box if the condenser coils can dissipate heat to the ambient air. And of course, ambient air temperature has a direct effect on heat dissipation, regardless of proper air flow.
Good luck in the search.
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If only you could have some kind of absorption unit to pre cool the air to then cool the coils on the fridge...
__________________
1971 Boler 1300 - "Suite 13"
1987 Play-Mor II - "The Beach House"
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08-03-2017, 11:41 AM
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#7
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Senior Member
Name: Clif
Trailer: 08 Weiscraft Little Joe 14 Subaru Outback 2.5i CVT
Louisiana
Posts: 754
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Quote:
Originally Posted by Johnny M
If only you could have some kind of absorption unit to pre cool the air to then cool the coils on the fridge...
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Yeah, like a chiller on a large commercial AC or refrigeration unit. I guess you could mount some sort of evaporative cooler panel on the lower intake, which might help in dryer climates.
__________________
Clif
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08-03-2017, 11:51 AM
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#8
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Senior Member
Name: John
Trailer: '71 Boler, '87 Play-Mor II
Deep South
Posts: 1,261
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Here is a refrigerator from SunFrost that uses only 12 amp hours per day 12vdc at 90 degrees, and only 8 amp hours at 70...They also have one with an ice tray compartment...might be a viable option...
R4 Energy Efficient Refrigerator
__________________
1971 Boler 1300 - "Suite 13"
1987 Play-Mor II - "The Beach House"
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08-03-2017, 12:00 PM
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#9
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Member
Name: Jeroen
Trailer: Scamp
North Carolina
Posts: 83
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It costs $1,875 and on top of that they charge your a $45 crating fee, for something smaller than a $130 mini fridge at Home Depot.
With solar panels being well under $1/watt I don't think it's worth it at that price.
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08-03-2017, 12:08 PM
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#10
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Senior Member
Name: Kelly
Trailer: Trails West
Oregon
Posts: 3,046
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The best option for making sure things will stay cold enough to meet food safety standards is to get a unit that is rated for freezing as well as refrigeration above freezing. Do a search on "12 volt fridge freeze".
Yes they cost more but you do need that type if you to have want reliable cold storage temperatures. And you do want to have that
Don't worry about what they call it, just pay attention to the temperature range it is rated for. If it does not cool below the freezing temperatures don't waste your money on it. The ones that don't go below freezing can't be relied upon in hot summer weather to keep your food safe or your drinks refreshingly cold.
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08-03-2017, 01:04 PM
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#11
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Senior Member
Trailer: Trillium 2010
Posts: 5,185
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Quote:
Originally Posted by jeroen
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At 65 watts on DC these will use over 5 amps continuous. In one 8 hr night it would drain a group 24 battery to 50%. On AC a dorm fridge would work better at half the cost. Peltier effect is too inefficient to be useful, don't waste your money. Unless you use a generator there are just three off grid options. Ice, propane, or DC compressor like the danfoss. The last one still requires significant recharge capability. Three way fridges show up used on Craigslist from time to time.
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08-03-2017, 01:15 PM
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#12
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Senior Member
Name: John
Trailer: '71 Boler, '87 Play-Mor II
Deep South
Posts: 1,261
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We recently came back from a trip with a cooler full of ice and had our breakfast sausage, deli ham and some hotdogs on top in a plastic zip lock baggie to keep water out and to keep from contaminating our ice for drinks. I put 10 lbs of ice in it when we left FL and when we got home (6 hours or so later) I used a digital thermometer to check the temperature of the meats and the sausage read 60 degrees sitting on top of the ice with the lid kept closed during the trip except for an occasional drink or ice accessed out of it. There was still ice but more than half had melted. None of it was below 40, we threw it all out...
For that reason I am seriously considering our options for on the road refrigeration, either an inverter for our dorm fridge or another type of DC powered unit...
__________________
1971 Boler 1300 - "Suite 13"
1987 Play-Mor II - "The Beach House"
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