Compressed Air From Water Tap

Did you know you can have free compressed air at home just by harvesting the pressure from a water tap?

Step 1: Tank and Conncetors

The most important piece of this project is a tank. This airtight tank which is filled with atmospheric pressure air will have two connectors one for the incoming water and one for the outgoing compressed air. I also swapped the original useless cap for a DIY made one which I made out of a Sprite bottle. I also added an air pressure gauge on top of this cap to monitor the tank pressure.

Step 2: How Does It Work?

So our tank here which is already filled with atmospheric pressure air is also connected to the water tap. By opening the water tap because the water in the water tap has a much higher pressure than the air inside the tank, it can force itself in. On the other hand, because the tank is airtight and does not have any hole for every drop of water that gets in the volume of the air inside the tank shrinks so the air pressure goes up. At this point, the pressured air inside the tank would be easily visible on the gauge. This progress will continue until the pressure of the air inside the tank will be equal to the water pressure that comes out of the tap. Now by opening up the air nozzle you can use the compressed air for all sorts of applications. Please note that the amount of pressurized air is dependent on the tank volume.

Step 3: Does It Work in Real World?

Yes, it does, I managed to achieve up to 30 PSI of air pressure just by using a city water tap. this is the normal tire pressure for many passenger cars today.

Drawbacks? well, besides the water that after each use you have to find something to do with so it won't go to waste, as I mentioned earlier the volume is limited to the tank size. In my case filling up a 15" tire at 30 PSI with a 20-liter tank required two full cycles, meaning that you will almost have 40 liters of water in hand to do something with.

I hope you enjoyed this Instructable, you can also check the video tutorial of this project by clicking on the video which is located at the top of this page. Please feel free to ask any questions in the the comment section below and also, you can check my YouTube channel for more projects like this.