Small Residential Freezer
How would you calculate how many amp hrs would be needed to run a small residential freezer for say 12 hours with an inverter when you (with out buying it and testing it) when you have no idea how man...
Forum Discussion
AStinker- wrote:
I would think 90 amp hours in 24 hours is pretty good. I'm looking at a 5 cu ft partly because smaller freezers the annual kWh were almost as high. Sorry but guess I don't understand how insulation quality would help in this calculation.
Perhaps my answer sounded too simple. It is difficult to tell exactly how much it will draw. 90 AH per 24 hours is not uncommon. And it can also be anywhere from 70 AH per 24 hrs on a cold day with no door openings to 120 AH when it's hot outside and you keep on adding warm food in there. Lower priced small frigs are usually less efficient per cu.ft. than bigger and/or more expensive models.
Insulation is important around the whole fridge body, but this factor is more relevant to portable and built-in 12V models like Engel, Sundanzer, Tundra (aka Waeco aka Dometic), Novakool, Isotherm etc. They usually have less insulation (= less thickness) than residential 120V units, so they benefit more from added insulation. Realistically, added insulation is a 2" or 3" block foam, the thicker - the better. Vacuum panels is more a dream than something that people use in Rvs.
Well insulated 5-6 cu.ft. 12VDC fridge will draw about 30%-50% less than similar size 120V residential model, and adding insulation around residential won't help much because they usually have enough insulation already.
What makes 12VDC models different is that they use a DC compressor with zero startup current, and there is also zero inverter loss because they need no inverter. This is the direction that you should consider if you want 3 day camping with minimal use of generator.
MEXICOWANDERER wrote:
Opinion: This would never be the answer for me. Not when boondocking and losing money on recharging like there was no tomorrow.
x2.
Residential fridge running longer than a day or two, means a generator.
Edit:
Ops - have just noticed that you wanted a freezer - not a fridge. Then, 12V chest freezer is what I would get. Sundanzer, Engel, Steka, Dometic, Novakool. Most 12VDC line-ups have chest freezers.
