Building a Mini-Fridge powered by a PELT!

[Suma]

Hey guys,
I need some help with this new project I want to start.
I always hated going all the way to the kitchen for a cold coke, so I figured I can use a nice (*cheap*) mini fridge in my room.
The reasons I want to use a pelt are:
a) noise will bother me
b) the size of the frigde will be tiny, compressor will be probably overkill.

The plan is to create a sealed area contaning ~25-30 Litres.

I really don't know what pelt power/wattage do I need, and in what way it should be cooled, air?, water? (I do have an old homemade block and a 400lph pump in spare) or how about a quiet passive heatsink?

The PSU I thought to use is an Achme 200w mini-psu.
The 12v is rated @ 10A.

I need your guideness thorugh this project.

Thanks alot!
Suma.

[Ugly n Grey]

There are pelt fridges for sale in most camping and hardware stores.. small ones and big ones like coolers etc.. you might be able to rip a few ideas off them by taking a look.

[Bloody_Sorcerer]

most minifridges are TEC-based. Considering your powersupply, I'd reccomend an 80watt peltier, with aircooling on both ends. True, pulldown times won't be incredible, but, given time, it'll do its job.

[Suma]

most minifridges are TEC-based. Considering your powersupply, I'd reccomend an 80watt peltier, with aircooling on both ends. True, pulldown times won't be incredible, but, given time, it'll do its job.

Assuming I will use a 80w pelt just like you said, what temps should I expect?
Let's say the room temp is around 20-25c

Thanks,
Suma.

[Ugly n Grey]

for 25 litres of air/liquid volume? Someday, it will get cold in there.... say 10c at a guess similiar to camping coolers...

[Suma]

for 25 litres of air/liquid volume? Someday, it will get cold in there.... say 10c at a guess similiar to camping coolers...

Mostly air, probably a 2 Litre bottle and a couple of beers.
That's all.

Suma.

[Ugly n Grey]

hmmm might draw down fairly quickly then.... still think that temp is a reasonable goal, possibly less on an overnight depending on insualtion quality

Try it and let's see!!!! :banana:

[Suma]

I still need to figure out what pelt to get, do you think a 80w will be enough to achieve 4-5c ?

Suma.

[Holst]

Depends on your insulation and hot side cooling.

If you can insulate it real good then 4-5*c should be possible with an 80watt tec.

Watercooling the hot side should get you much better temps. Watercooling will also make insulating easyer and might make the unit quieter.
if you are aircooling you will find it hard to get good insulation of the cold side and will loose efficency.