Who Invented The HVAC Thermostat?

Discussion in 'Off-Topic' started by Glenn Holland, Feb 28, 2015.

  1. Glenn Holland

    Thread Starter Member

    Dec 26, 2014
    There was a previous post on HVAC and that aroused my interest in the history of automatic temperature control systems.

    I'm quite certain National Regulator Co. of Chicago was the first commercial suppliers of thermostatic controls for building heating and this is one of the company's brochures:


    (To see the pictures, click "Full Text").

    From the brochure, National supplied thermostatic controls for a lot of school buildings and any other project where they could "get their foot in the door" of the architects and sell an installation.

    In fact, my elementary school building (built in 1908) was equipped with a thermostatic control system for steam heat radiators that I believe was made by National Regulator Co. However, the thermostatic control was pneumatic instead of electric and air was supplied through a network of tubes connected to a compressor in the boiler room.

    Each class room and office had a rather ornate looking wall thermostat that used air pressure to operate the steam valve on each radiator. As a young geek, I learned how to troubleshoot the system and if the heat wouldn't come on, I knew to listen for a slight hissing sound from the thermostat then ask the custodian if he remembered to turn on the compressor.

    Few -if any- of National's now antiquated pneumatic control systems are still in service, but I've seen a few 1900s vintage buildings where the ornate wall thermostat was retained for decorative value.
    Last edited: Mar 1, 2015