Everyone is familiar with pinwheels, and few of us haven’t crafted one from a square of paper, a stick, and a pin. Pinwheels are pretty optimized from a design standpoint, and are so cheap and easy to ...

[Nubmian] wrote in to share his experiments with measuring airflow in an HVAC system. His first video deals with using with ultrasonic sensors. He found an interesting white paper that described ...

In 1970s Iran, entrepreneur Hamid Farzaneh started a company that installed heating and cooling systems into the homes of wealthy Iranians. But he noticed a problem: The HVAC systems only gave people ...