Book 25, Question 24
How do big buildings stay warm in winter and cool in summer?
Big buildings have heating and cooling systems with boilers, chillers, ducts, and fans.
Air is heated or cooled in machines and sent through ducts to every room. Sensors and thermostats adjust the temperature in different zones. Filters clean the air. Smart controls and good insulation save energy. Some systems recover heat from the air leaving the building.