Weekly Update: Project Clean Up Newsletter - Vol. 1, Issue 66

Date: September 25, 2026

The Climate-Controlled Human: Phase Change Materials and Personal Thermoregulation

Welcome back to the Project Clean Up (PCU) weekly newsletter! Last week, we explored how Thermoelectric Generators (TEGs) are allowing us to harvest the massive amounts of waste heat bleeding off our factories, engines, and data centers.

Today, we shift our focus from the macro-industrial scale to the most intimate surface imaginable: your skin.

Consider the absurdity of modern HVAC systems. We spend massive amounts of energy—often derived from fossil fuels—to cool or heat a 50,000-square-foot office building or a large apartment, simply to maintain the temperature of the few human bodies occupying a tiny fraction of that space. We are conditioning empty air.

What if we didn't have to control the climate of the room, because we could seamlessly control the climate of the person? This week, we explore the advanced textiles making the "Personal Microclimate" a reality: Phase Change Materials (PCMs).