New Fridge Solution? Or Just Clever Marketing?

[SURV69]

for now I just snug fit them.

Last night 11pm-4am, with the unit off, I lost cooling from 31 degrees to 47 degrees, which amounts to 3 degrees an hour.

I turned the unit back on at 4:30am. When I was awaken at 9:00 am, the unit was 33 degrees(4.5hrs), with an ambient of 69 degrees.

A few hours later the cooler was 29 degrees with an ambient of 81 degrees(52 degree difference).

At 4pm, the cooler was at 27 degrees(80 degrees ambient), and at 7:00pm(minutes ago), it was 28 degrees at 78 degrees ambient.

Still ... with the unit off, plus the added insulation, I lost 16 degrees in 5 hours.

I still wonder if the peltier, when off, is making small amounts of electricity which could explain the high rate of cooling loss(the peltier is still in a circuit even with the 120-12 volt transformer unplugged?).

I might try to manually insulate the turned off(?) peltier from the rest of the cooler to see what happens.

If any of this proves fruitful, I hope to have a unit that operates less than 50% of the time.

Years ago, I never had this much loss(when off). Since then, I added a larger fan to the internal heatsink. Maybe the fans are the resistance that is causing/allowing the peltier to make electricity?

[socaldmax]

Interesting thread! I agree, you seem to have greatly increased thermal efficiency by increasing the insulation. I think you may also be correct that the Peltier Junction could be converting thermal energy into electricity via the Seebeck effect. For that to happen, there must be a complete circuit for electrons to flow.

You could cut one of the fan wires and add another switch to isolate it from the PJ, or just leave it on all night. I'm not sure that you're saving all that much power turning it off every night. If temps are cool and you don't open the lid, you'll use XX amount of power every night maintaining the desired temp. If you shut it off, it still has to use YY amount of power to get back down to temp, the power savings may not be all that great, especially compared to the shortened shelf life of any perishable foods, if any.

If you have a cumulative ammeter of some sort, you could probably measure the difference.