Mark Feldmeier General Exam --8.20.7 Distributed Control Systems Examiner: Joe Paradiso Problem 1: History of Distributed Controls in Building Hvac Control

Depending upon one's perspective, distributed control has had an either extremely long, or extremely short history in the application of heating, ventilation, and air-conditioning (HVAC) control. HVAC systems have been in existence for the entire duration of human architecture, at least in terms of heating, with air-conditioning arriving in the 1800's with the industrial revolution, as a means to improve profits. These systems would be controlled with a human operator in the loop, making decisions to maximize the thermal environment under limited resource constraints. The need for the human was alleviated in 1885 when mechanical heating regulators were brought to the market by Honeywell (the thermostat, although having been invented in 1572, didn't come in to common use until being integrated into a heating unit). It wasn't until the 1920's that such systems became prevalent.