Is Anyone Handy?

[Frankophile Feline Fan]

I'm trying to make a decision on a Peltier refrigeration appliance. I feed my 7-month-old junior cat 50/50 thawed Primal frozen raw and Instinct cups. To feed her more reliably, more often, and when I'm away, I'm looking into a mini 6-pack refrigerator (the bottom picture) and came across this new thing on Amazon.com without enough information on it's reliability.

I tried the Catmate C500 automatic feeder with ice packs but it failed food safety miserably: Food temperature was 70 degrees after 6 hours and I started with frozen ice packs and Primal blocks! The food safety zone is below 41 degrees.

So I'm going to experiment with teaching Colette to open the mini fridge. (I may have to rig a new latch system with magnets and a strap). She paws at food she doesn't want at any particular moment so she may be able to close it, too. If this doesn't work out, there are guides on YouTube to build your own Peltier refrigerator. I'd use the parts from the mini-fridge and styrofoam sheets to build around the Catmate C500.

This is my plan, but then I found this new device that could simplify things, but a little more difficult to cover uneaten wet & raw food. I'm thinking with the first appliance, I'd attach a strap to the top that Colette could handle. If I could make a cover on a rotating pivot, that would be easiest for Colette to manage with her digging instincts.

Any advice? Thank you

 

[Margret]

Can you give us more information about the new refrigerator you found on Amazon? I can't tell anything from the pictures, not the name of the device, not where the door is, nothing!

Margret

 

[Frankophile Feline Fan]

I already asked the Amazon community about 4 different types of handles I've seen on the mini refrigerators. Answers are uncertain for all of them.

 

[Margret]

A careful reading of the description and close examination of the buttons appears to indicate that the possible settings, in degrees Fahrenheit, are 8º (frozen), 45º, 55º, 70º, and 120º. As far as I can tell, it's intended to hold a single can or jar, and you would get into it by removing the translucent lid from the top.

Your kitten might well be able to get the lid off, but 45º is warmer than you need, and 8º is a great deal colder. It's an ingenious product, and I can see that it might be quite helpful in some situations, but I really don't think it will do the job you want it to do. I also have some serious reservations about the insulating properties of the translucent lid.

Margret

 

[Margret]

Just looked at the second one you linked to, and I can't think of any way for a cat to reliably open it. Also:

The mini fridge works without any liquid refrigerants (like freon), noisy motors or messy condensation. Works best with cans, for best results with other food, wrap in aluminum foil.

I'd like very much to know what mechanism it uses to cool, that requires you to use metal in food packaging; that sounds wonky to me.

Margret

 

[vince]

I have an old picnic cooler that uses a Peltier Junction element. It's okay for a short while, but doesn't really keep things cold well. This is only my own experience with a 25 year-old piece of equipment. They probably have improved them over the years.

As for the temperature setting, I'd guess it uses a thermistor with some kind of hysteresis circuit to make it snap on and off at a specific temperature. The temperature switches on the unit you depict might be used to switch additional resistors in and out of the thermistor's circuit, allowing some variation of controlled temperature. You might experiment with the choice of resistance to get the exact temperature you need (this being predicated on the temperature control being of the type I think it is).

In response to the question about using only metal containers, Peltier junctions have no such specific restriction. I suppose the recommendation was made on the tight seal offered by a metal container and the relatively fast heat transfer offered by such a container. One could just as well use Tupperware.