Multi-zone electric thermostat
Termostato eléctrico multizona
- Date
- 1883-1886 · confidence high
- Place
- Whitewater, Wisconsin, United States
- Credited to
- Warren Seymour Johnson (1883 patent); Albert Butz (independent electric thermostat, 1886 patent)
- Field
- Tools
⚠️ Disputed: the sources disagree.
What it is
Professor and inventor Warren S. Johnson patented in 1883 a bimetallic thermostat able to electrically control several heating zones of a building remotely, improving on earlier rudimentary temperature regulators; shortly after, in 1886, Albert Butz separately patented an independent electric thermostat.
Before Johnson, Cornelis Drebbel had built around 1620 a mercury thermostat for an incubator, and Andrew Ure designed a bimetallic regulator for textile mills in the 1830s; credit for the 'first' modern thermostat is disputed among several inventors.
What it led to
- automatic temperature control in buildings
- founding of the Johnson Electric Service Company, later Johnson Controls
- widespread adoption of regulated central heating during the 20th century