Instructables
Too hot or too cold? Make it just right (and make Goldilocks proud) by building this dual-purpose device.

Down here in Arizona, we've got some pretty hot summers, at around 120 degrees. And inside, it gets up to about 88, which is a bit hot for my taste, especially when I've got my computer on- then it's even worse.
Or, if you live somewhere cold and wish your room was warmer at night, just flip a switch and your wish will be granted with this air cooling and heating machine.

And it's cool looking too!
 
Remove these adsRemove these ads by Signing Up

Step 1: Materials

Oh man. This project requires a bunch of stuff, but you probably have most of them lying around from old broken things.
You do keep old things you don't use any more in a parts closet, right? Good.

-2 80mm computer case fans: I used one of a normal thickness and one half-sized one with more blades. You'll see why later.
-A transformer: I got mine from an old speaker set that I converted to run on batteries. It steps 120VAC down to 13.5VAC.
-4 diodes for making a bridge rectifier: Also from the speaker set; converts AC to DC.
-A 4700 uf capacitor: That's all I know about it. It just came from the speaker set, but I only know that it's 4700 ohms. It filters the DC current so it doesn't pulse.
-A 60mm x 60mm heatsink: Mine's aluminum. Bought on eBay. Right after I got rid of a bad computer motherboard I could have taken it off of. Oh well.
-Thermal Tape/Compound: Used for attaching the heating device to the heatsink.
-52mm Peltier Cooler/Thermo-electric cooler: Bought on eBay, it's the heart of this project. It gets hot on one side and cold on the other. You could probably find one on an old camping cooler along with the heatsink.
-A 6"x4"x2" project box: A bit tight for this project, you could get one that's a little larger.
-3 SPDT toggle switches, or 2 SPST and 1 SPDT toggle switches: For switching things on and off.
-A general purpose PC board: Got it at RadioShack; it came with two boards with 213 holes each. Perfect for this.
-2 1.5K ohm resistors: For the LED's.
-2 LED's: Any color, I choose one green and one red.
-A piece of flexible plastic: I got mine from the bottom of a dead power supply, but you could use anything that's thin and non-conductive.

And some basic tools:
-Soldering Iron
-Rosin Core Solder
-Drill with bits
-Hole-Cutting Bit
-Dremel with Cut-off Discs (Best tool ever!)
-Insulated Wiring
-2-prong electrical plug with cord
-Heatshrink Tubing or Electrical Tape
-Hot Glue Gun: (Optional)
1-40 of 104Next »
Try this Instructable:

Mini Peltier Air Conditioner (Plans)
http://www.instructables.com/id/ED7RWABG8ARZSCG/?lang=en
anirwan4 months ago
can u upload a working video of it please...
autumnwind32 years ago
For the folks looking for parts, try American Science and Surplus. They had a Peltier junction in stock last time I looked. I always look for unusual parts there first.
TeslaBoy2 years ago
might want to clean up your schematics and why not just get a pc rectifier then bother with the whole diode setup
rHid0c3roZ6 years ago
so.. how bout the temperature? can the air cooler reduce heat better?
videokid842 (author)  rHid0c3roZ6 years ago
Well I've been having some problems with my Peltier unit for some reason. I'm not overloading it, but it seems like the cold side will get cold for a couple minutes, and then start heating up, even though I've got the hot side heat-sinked. So I don't really know what's going on, and that's why I don't know how cool it makes the air. If any of you know why this is, I'd really like to here from you.
you will need a fan on the hot side along with a heatsink because after a few minuts the heat overpowers the cool i found this when i firs got mine and it never made ice like it said it would a quick wikipedia search revaled the answer the hot sid's heat has to be dicipated in order for it to work
videokid842 (author)  junits155 years ago
Alright, thanks I'll try that. I tried to use mine to make a "mini fridge" out of cardboard (I know...) and was having that heat problem. I used just the cooler connected with an power indicating LED, both connected to this bridge rectifier circuit and transformer. Then, the 3rd or 4th time I plugged it in (I had only had it running for about 5 minutes the other times) the LED dimmed, then I heard a pop and some smoke came out of the little box I had put the circuit in. And smoke is never a good sign. So after it was unplugged for a while, I checked it out, and one of the diodes had split in half, one half became completely unsoldered, and the plastic housing was at the bottom of the box. So now I think I'll just buy a 12 volt wall wart or something. :D
if you have one use a computer power supply there is a great instructiable on how to make one power up without a MB and a wall wort will never have enough amps to support that peltier it will also burn out
bcraun junits152 years ago
+1 as I've experienced this. Wall warts are not designed to deliver the current required by a TEC. The ones I've worked with generally draw between 3-5A.
videokid842 (author)  junits155 years ago
Alright thanks I might try that.
i plan on making an instructible very similar to this (it will be my first!) if thats alright with you though
videokid842 (author)  junits155 years ago
Yeah, that's fine. I'm sure anything that that doesn't split diodes apart will be great. :D
im hoping it wont! ;)
also give this a try get your seccond heatsink and a small plastic box put some water in the box, and salt it very thouroughly put your larger heatsink in it and and leave it in the freezer for a night and then in the morning hook it up to the computer power supply and make sure the hot side is on the heatsink in the ice and attached very firmly attach the black wire to any black wire on the power supply and the red to any yellow, if it works right it should frost up in a few secconds. BUT watch the water temp and make sure it dosn t get to hot, because the ice will melt into water (also double check the voltage from those two wires and make sure it wont overload your TEC :D)
videokid842 (author)  junits155 years ago
Now all I have to do is find a power supply to do that with....
r u in school? if you are ask your tech teacher for and old one that they dont want be sure to be very polite and they might give you one also check ebay and craigslist
videokid842 (author)  junits155 years ago
Yeah that's an option...unfortunately our "e-waste" collection just ended and they already took all the computers and stuff to wherever it is they take them.
oh then i realy have no idea on where to get one, you could check ebay thell proablly have one but dont count on it._.
also i plan on making a air cooler/heater/mini fridge ist gona be awsome! also it is taking a long tome so dont expect to see it for a few weeks! :D ._.
videokid842 (author)  junits155 years ago
Haha okay, just drop me a comment or message when you finish.
ahhh. you let the magic smoke out! (search it up on wikipedia)
bowmaster3 years ago
About the fans: Lots of blades means lots of air, but also lots of noise. Fewer blades means less air, but also less noise. That's why fans you buy at the store fo cooling rooms have fewer blades, so they will be quieter.
With computer fans, it usually has more to do with RPM than blade configuration
I always thought it was the other way. My 9 bladers pull maybe 35-40DBs alone, but I see 3 blades that pull about 65DB. Sure the 3 blades were moving about 150-200CFM, but for a 120mm fan, 60DB is a bit much.
Yeah, if you have a bunch of different things it'll vary, but that's what I've noticed.
Yuor proyect is so practice. Some one Know how to maque a Peltier module.
Thanks to very much
SAludos

Juan Saab-Rafful
Rybka303 years ago
I think it´s only air heater - energy only make energy.
I think that energy what you put to it=heat, what you get from it.
It´s physical rule. you can chill some space, but in the fact, you will heat air in the room, but not all air...
I apologize for my English.
neodymio3 years ago
The module peltier needs a 6 amps power supply, diodes can dissipate high amp? diodes 400x dissipate 1 or 1.5 amps
fauge73 years ago
we in az just had snow in peoria!!! its too cold for us in the valley
fgonzales3 years ago
I think you wired your bridge rectifier wrongly. Take note of AC input and DC ground.
mr. clean4 years ago

how many watts is ur peltier unit and what happens if u reverse the polarity to the peltier unit?

If you reverse the polarity, the side that is meant to get hot will get cold, and the side that is meant to get cold will get hot.
kretzlord6 years ago
I don't want to take away from the awesomeness of this at all, but to be really effective, the opposite side of the peltier that you aren't "using" should be exhausted into a room/outdoors where you are not. Just a thought, great Instructable!
Yup, without having one side connected to outdoor air (preferably also drawing in outdoor air), all this will do is heat the room it is in. It may cause local cooling within the room, but overall it will heat the room. 1) If being used as a heater, it will be a lot more expensive than just a set of resistors. (Things change a lot if it is pulling heat from the outside air.) 2) If being used as a cooler, it would only be good for keeping PC components cool, or cooling off a drink (or drinks). 3) It might work well as a dehumidifier if you run ducting such that air that passes over the cold heatsink then passes over the warm one. This will condense water out of the air on the cold HS, and then warm the air back up, providing warm dry air. (Good if the room is cold and humid, and the one case where it would be a better solution than a purely resistive heater.)
The laws of thermodynamics FTW.
dagenius4 years ago
Ah, but you see, by the laws of thermodynamics, this will not work. What I mean by this is that although the peltier unit cools one side, it heats up the other, and because it does have internal resistance, the heat will inevitably overpower the cold. while it may cool down the air directly in front of it, it creates heat elsewhere. What the peltier unit does is absorb heat on one side, and release it on the other.
bowmaster4 years ago
This looks nice. Could it keep a 4'X8'X2' padded box at ~72 dregees F in 100 degree F weather for a few hours?
Would this be a box of your native soil in which you take refuge during the daylight hours? It probably does get kinda stuffy in there, especially during the summer months.
No really, more of a closed up climate controlled bed.
1-40 of 104Next »