Introduction: How to Make a Dehumidifier (Thermoelectric Cooling)
If you live in a humid area, or want to decrease the level moisture inside your house to prevent the growth of mold. This is the perfect Instructable for you, because I'm going to show you have to build a very easy to build dehumidifier from inexpensive parts you can find on Ebay. It will quickly remove moisture from the air by a phenomenon called condensation.
Basically we will build a device that extracts water from the air, maybe it also has a secondary use? Comment below!
Step 1: Materials
One of the main components is the peltier chip, also called a thermoelectric cooler. This is a 40x40mm chip that does something amazing! When powered from a 12V source (like a battery), one side will increase in temperature while the other side will decrease. The temperature difference is the required condition to make the water vapour in the air around us to transform into a liquid state, also called condensation.
You will also need an electric fan to pull the humid air through the device. The heat sinks will spread the heat and cold, making it more effective. Heat sink compound is necessary to achieve a good surface bond between the peltier and the heat sinks.
You can power the dehumidifier by either a 12V battery, or an adapter. In this Instructable I will be using a lithium polymer battery.
-Computer fan http://www.ebay.com/itm/152164778088?_trksid=p206...
-Large heat sink http://www.ebay.com/itm/322153363563?_trksid=p206...
-Small heat sink http://www.ebay.com/itm/331591409583?_trksid=p206...
-Peltier chip (thermoelectric cooler) http://www.ebay.com/itm/291568790291?_trksid=p206...
-Heat sink compound http://www.ebay.com/itm/391205942743?_trksid=p206...
-Scrap material, such as foam.
-12V battery http://www.ebay.com/itm/11-1V-3000mAh-30C-3S-Lipo...
All these parts can be found on Ebay for under 30$! You will also need some tools:
-Screwdriver + screws
Step 2: Assembly
Fasten the 80mm electric computer fan to the larger heat sink. This is the heat sink that will be increasing in temperature by the peltier chip. The fan will be pulling the air into the larger heat sink. Flip the heat sink over and add the compound to where the peltier will be placed.
Place the peltier chip in no specific orientation or upside/downside. If reversed, meaning the larger heat sink decreases in temperature, swap the positive and negative wires.
Place the peltier chip and press down firmly. Add compound to the smaller heat sink and push it agains the peltier chip. Screw it down if necessary.
Step 3: Stand
Take some scrap pieces of foam, or even cardboard, and cut 4 rectangular legs for the dehumidifier to stand on. Cut one of the short ends at a 45 degree angle and hot glue it to the fan as shown in the pictures.
Since the heat sink on the bottom will collect water it might start dripping if the air is humid enough. Make sure you have high enough legs to place a container underneath.
Step 4: Wiring
You will have a total of four wires, two from the peltier (black and red) and two from the electric fan (black and red). Solder the black wires to one of the pins on the electronic switch and solder another piece of wire to the middle pin from the switch.
Glue the switch to a convenient position on your dehumidifier, and solder the connector to the remaining two red wires and the black wire comming from the electronic switch.
I took the liberty to add LED lights, the main reason is because it makes it look better and lights it up during the dark hours. It also signals when the battery is connected to the dehumidifier, which can be very useful if you tend to forget things easily.
Step 5: Usage
Connect a fully charged battery, but remember to also purchase a small voltage alarm that will alarm you once the batteries is low.
After just 2 minutes drops of water is forming on the cold black heat sink indicating our dehumidifier is working properly. After 5 minutes the heat sink is covered with water extracted from the air. Proving that the device is very efficient and performs very well inside my garage where the humidity is low.
At just a 3 amps this setup will run for a little less than 1 hour. However, you can definitely get a much larger battery and achieve hours of run time on a single charge.
Don't buy does expensive dehumidifiers when you can build your own. Follow my instructions and you will have a device that runs efficiently, quietly and performs really well! Good luck, and comment below if you have any questions.
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