TECs sure can be fun!

[Rhith]

I started out small, didn't realize that some moving air would help keep the heat sink from become a fireball!

Then we got some fans going!

A few drips of water and a time later...

 

[jayhawker08]

nice. now, i don't know much about TECs, does the opposite side get hot (one side cold, the other hot)?

 

[dingle]

They pretty much move all the heat thats in them to one side, leaving the other super cold. There is a maximum difference of temp between the two sides, so cooling the hot side with a heatsink is essential to getting the cold side colder. Running for just a few minutes w/o a fan, the heatsink can become hard to pick up because of the heat.

 

[Rhith]

Exactly right! I had to use something to pick up my heat sink and move it to the freezer for a while when I didn't run it with any fans! :

 

[Greenie]

HeHe very nice.

 

[gyrodryve]

I've been playing with one recently too and did the no fan trick - had to pick up the heatsink with oven mitts. Bloody hell it got hot!

 

[charleytown55il]

what temp on the hot side will kill it?

 

[Things]

hehehe i love making ice with TEC's! once mine got down to about -8C and it froze the water as soon as it touched it! nice work!

 

[Rhith]

I'm not sure what temp will kill the TECs but if it's getting that hot in the first place it won't be able to cool that well so you'll know to turn it off and cool it down.

Also, I plan to get some thermal paste after school and that should help my TECs push a little harder. So far it seems that my smaller (30x30mm) TECs are running cooler then my larger (40x40mm) TECs. I'm guessing this is due to the amount of heat it is dispersing onto my heatsink that is preventing it from working as hard. This is another instance where I think a bit of thermal paste will eb helping me out.

 

[Tallaxo]

I have never been able to get my TEC that cold, hmmm, maybe I need to start using a heatsink, or up the voltage.

Jase.

 

[Cyparagon]

Stack three of them on top of each other and water-cool the bottom end. Maybe you can make liquid nitrogen.

 

[Aseras]

you need to pot your tec, coat the side with silicone, if you get water in there they'll die. it's especially important if you are goint to go subzero since the cold side will get condensation and after a while you'll gt corrosion in there you can't get out or clean.

 

[pseudonomen137]

Hehe, yep, if you plan on using a TEC for cooling, a heatsink is 110% mandatory. Deferring to the lovely "all processes are inefficient", if you don't have something to draw away the extra heat produced by a TEC, you're only going in one direction - hotter. Without a heatsinking, you'll eventually have a hot side, and a VERY hot side.

I have never been able to get my TEC that cold, hmmm, maybe I need to start using a heatsink, or up the voltage.

Jase.

 

[Tallaxo]

That makes a lot of sense, thanks Pseudo

Jase

 

[danielbriggs]

DON'T up the voltage too much. That will kill it. (kind of).
It's the current you need to crank up, I don't know what wattage peltier you've got, but if it's 200W say, it will easily (and happlily) eat 20 amps DC.

Also, if you can get your head round this, then you can do anything with TEC's!
The cooler the hot side, the cooler the cool side  
I'm sure there must be a better way to phrase that!

I used a couple of pelts in my school tech project, It was a drinks cooler / heater. It went on to win 1st prize in the UK national desgin competition  

Usually, you'll get about 67 deg C temp difference from one side to another. I have some current/temp graphs around somewhere. PM me if you're interested.

Dan

 

[a_pyro_is]

The cooler the hot side, the cooler the cool side

Mmmmm. Stacking TECs

GIANT fan
HUGE heatsink
Hot side of big TEC
Cold side of big TEC
Thin bar of Cu
Hot side of medium TEC
Cold side of medium TEC
Thin bar of Cu
Hot side of small TEC
Cold side of small TEC

Throw in a few thermal cutoff switches and see how cold you can make it. DIY dry ice anyone? I'd hate to try building the PSU for that monster.