Toggle, you don't need a gas flame for an absorption fridge; an electrical heat source will work as well and with high efficiency.
Nice article about the guy who converted the chest fridge. In fact that is absolutely brilliant and so simple I'm kicking myself for not having invented it. I was looking at chest freezers a while ago and got discouraged by the fact that they don't go above something like ten below freezing, but this idea never occurred to me.
What he's got there is an external thermostat that interrupts power to the chest freezer when the desired level of cold is reached. So you set the thermostat for, perhaps three to five degrees above freezing, or whatever you like, and that's all. Beautiful.
The chest freezer keeps its cold because when you open it, the cold air doesn't slosh out the door onto the floor. And if the article is correct, power consumption of 0.1 KWH/day = 36.5 KWH/year, which beats even Sun Frost.
Now the question is, what models of chest freezer could this be done to in the US? Or could the actual thermostats that come with these units be hacked like the water control on the Danby front-loader? So now we look up Danby chest freezers and discover:
Danby 3.6 cubic footer: 215 KWH/year.
Danby 5.5 cubic foot: 248 KWH/year
Danby 7 cubic foot: 276 KWH/year.
Something very cool about these (ha) is that they have oldschool ROTARY thermostat knobs on the front panel. Aha, says I! One of the product manuals says that the temp range is ordinarily -10 to -23 C (+14 to -10 F). So, I wonder about this: I'll bet that the thermostat is nothing more than a variable resistance. And I'll bet that adding or changing a resistor on the circuit board will change the effective temp range of the unit. If that doesn't do it, then the external thermostat control would do, as per the Australian article.
I found a Vestifrost 3.5 cubic footer that's rated at 248 KWH/year, so we can assume their ratings for their other units are similarly comparable. If the guy who hacked his freezer in Australia was using a 7 cubic footer, then we can assume Vestifrost would have been about 300 KWH/year un-hacked, down to 36 KWH/year hacked. Roughly speaking that's an 88% savings.
So now assume two Danby chest freezers (matched pair
, one converted to a fridge, and one used as a freezer. Let's assume that for regular freezer duty, you want a temp of maybe -5 C or maybe somewhere in the 20s F. I'm going to make a wild guess that if the freezer normally has a max temp of 14 F, and you tweak it so it's running at maybe 25 F, you save conservatively 30% of the rated power.
OK, so now our modded 3.5 CF unit used as a freezer would use 129 KWH/year, and our modded 5.5 CF unit, as a fridge, would use maybe 30. Total for both is about 160 KWH/year. Recall that our hypothetical SunFrost was 105 for $2,300.
And, you can always use the space atop the units as part of your kitchen counter space, though not for heavy work that involves a lot of weight or pressure. This also lends itself to a whole set of different ideas in terms of how kitchens are designed & laid out. Hmm....
