#10: Underfloor Heating Systems in Ancient Korea – Ondol
Ondol, a traditional Korean underfloor heating system, used wood smoke to heat thick masonry floors by transferring heat directly through smoke passages beneath the floor. The system involved a firebox, smoke passages, and a chimney, with the smoke circulating under the floor and heating it before exiting through the chimney. Ondol was so effective that it became integral to Korean architecture and culture, influencing modern underfloor heating systems worldwide.
