Part 9/14:
The invention of thermostats revolutionized heating control. In 1830, Andrews E. Earl patented a bimetallic thermostat that responded to temperature changes. By 1885, Warren Johnson perfected the automatic thermostat using compressed air to regulate steam heating, allowing users to set desired temperatures and have systems self-adjust—precursors to modern programmable thermostats.
The 20th Century: Electrification, Fuel Shifts, and Efficiency
The 20th century witnessed rapid expansion and modernization. The widespread adoption of electricity facilitated automatic valves and more precise temperature regulation. Advancements in insulation—particularly the development of fiberglass in the 1930s—and better building standards meant that homes could be warmer with less fuel.