This is the two in one air conditioner, the small portable tool that can be used to adjust your room temperature. This mini tool works in two main functions, cooling down the hot temperature and to heat up cold temperature using water steam. The design is simple, anybody can make it and it works pretty well.
This hot and cold air conditioner working principle is simple. The peltier will generate heat or cold which is spread to the water container. The water container will boil water or cool it. Then at the same time, the blower is sucking and blowing the water steam to your room. You can swap the peltier side to choose hot or cold anytime easily.
There are three main parts, the peltier / thermoelectric cooler (TEC), metal water container, and air blower.
How Peltier Works
Peltier has two sides, when you connect a power source or battery to this peltier. Peltier will generate heat on one side and cold on the other side. So this is the main idea why this portable air conditioner can be used to cool down or heat up air temperature.
Water Container as Hot or Cold Steamer
Water Container has to be made from metal, can, or something that absorbs cold / heat . When the Peltier generates heat or cold, it will be channeled and spread to the water container. I used aluminum because I have it from unused junks, and aluminum is one of the best metals to absorb heat or cold. But if you don't have it, you can use biscuit can or even corned beef can.
Put the Peltier to the center of the water container. Fill and refill water to the metal container. And the small tip in the cap is used as a lock. Simple mechanism that works pretty well. See also self watering machine for plants.
Air Blower Best Design
I have made a video to make it, but I will explain it here. The impeller fan is placed slightly aside, not in the center. Because if you place the impeller in the center, the air is flowing everywhere, it's unchanneled. But if you put the impeller a little bit aside, the air will come from the center. Then air is flowing from the narrow space, gathering here in the wider space and blowing out. So the air volume is greater about twice or three times more than the centered impeller.
You don't really need a bigger dc motor or bigger fan, just make the right design. I only used a very small dc motor from joystick vibrator dc motor, a lightweight impeller fan from soft drink can, with very smooth spinning and very low noise.
Since the air blower is intended to blow cold or hot water's steam. You need to make holes, air sucking holes. You must carefully choose the hole position. I made some small holes in the bottom and the holes are a bit italic. Because I don't want to ruin the air flow. If you make a single wide hole the air will be thrown away, even blowing the hot / cold steam the wrong way and making the blower more noisy. That's why several small holes are better than single wide hole.
Demo Video & Addendum
I also use a PWM controller to adjust air blower speed. And for better results, you may add several peltiers and make sure to use adequate power current. Some Peltier can take up to 6 amperes, depending on the peltier's type.
Another easier hack is to modify a premade air conditioner. There are many cheap mini air conditioners you can buy from online marketplace. All you have to do is to make holes at the bottom, patch it with metal then attach peltier to it, easy!