Air Cooler/Heater

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!

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)

Comments

[autumnwind3]

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.

[TeslaBoy]

might want to clean up your schematics and why not just get a pc rectifier then bother with the whole diode setup

[bowmaster]

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.

[lloydrmc]

With computer fans, it usually has more to do with RPM than blade configuration

[_Scratch_]

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.

[bowmaster]

Yeah, if you have a bunch of different things it'll vary, but that's what I've noticed.

[juan saab-rafful]

Yuor proyect is so practice. Some one Know how to maque a Peltier module.
Thanks to very much
SAludos

Juan Saab-Rafful

[Rybka30]

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.

[neodymio]

The module peltier needs a 6 amps power supply, diodes can dissipate high amp? diodes 400x dissipate 1 or 1.5 amps

[fauge7]

we in az just had snow in peoria!!! its too cold for us in the valley

[fgonzales]

I think you wired your bridge rectifier wrongly. Take note of AC input and DC ground.

[mr. clean]

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

[dagenius]

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.

[kretzlord]

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!

[Entropy512]

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.)

[dagenius]

The laws of thermodynamics FTW.

[dagenius]

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.

[bowmaster]

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?

[Mr. Potato Head]

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.

[bowmaster]

No really, more of a closed up climate controlled bed.

[Mr. Potato Head]

Same difference...

[natester632]

How many volts should the fans be??? please respond

[videokid842]

I used 12 VDC fans with the ~13 VDC transformer, but if you're using a different transformer, you may need to add resistors or get fans of a different voltage.

[natester632]

hey uh where do u get the peltier thingy? like wat thing can i take apart and find that thing inside of?, please respond

[kington99]

those mini fridges you can get for keeping drinks cool have a Joule-Peltier effect system in them, which would be around the right size for this project

[natester632]

Anything else lol I don't have a fridge I want to destroy lol

[suza_phone]

Can you say where you got the thermal tape from? Thaaanx.

[videokid842]

I found it at Fry's Electronics.

[zack247]

what about in canada?

[kalo02]

potential for it to be solar powered?

[zack247]

maybe with one of those car battery charger solar panels, they have to put out about 13v to charge the battery

[firechicken]

do you sell these portable air conditioner and will it cool an old car

[tech-king]

that cap is 4700 uf, not 4700 ohms

[videokid842]

Right, sorry. My bad; it's resistance that's measured in ohms. It's fixed now.

[TogetherinParis]

Resistance is futile anyway.

[lane29]

do you live in atlanta

[electronicdude]

Instead of going to the trouble of building the 120 volt AC to 13.5 Dc adapter, just use a 12 volt wall wart. Its safer to use than having 120 volts coming into your container. Its simpler, and saves time and money.I realy like the saving money part about it. I can go into RadioShack for a very simple and small project and spend $25. The main thing is use a wall wart.  

[uberdum05]

You might want to use a centrifugal fan or a squirrel cage fan to get more airflow :)

[mr. clean]

haha u sure have a mess going in the background in ur first pic.

[ibuildcoolstuff]

would it be possible to do this with two project boxes. Have one housing two or so of these trasnformers and have the other hold two or three peltier units as well as the fan so you could get even more cooling.