Clean Air at Home – Building Your Own Air Purifier

Imagine living in a city where the air is so polluted that stepping outside feels like breathing smoke. That’s what happened to Professor Thomas Talhelm in Beijing. Instead of buying a fancy $1,000 air purifier, he rolled up his sleeves and built his own for a fraction of the cost—and it worked! In this project, you’ll follow in his footsteps. Your mission: design and build a low-cost air purifier that can actually clean the air in your room. You’ll discover how air purifiers work, why HEPA filters are so good at trapping tiny particles, and how to make air flow work in your favour. Then you’ll sketch your design, gather simple materials like a household fan and a filter, and start building. Once your purifier is ready, it’s time to put it to the test. You’ll measure the air quality before and after running your machine, see if your design works, and think about how you could make it even better. By the end, you’ll realise you don’t need expensive gadgets to solve real problems—you just need curiosity, creativity, and the courage to try.