HVAC controls history and theory 101

[@rcxuniversity1977]

For those still working with pneumatics, here you'll find some resources that may be helpful: av8rdas.wordpress.com/2013/03/03/pneumatic-controls-resources/ and av8rdas.wordpress.com/2013/02/15/pneumatic-controls-first-cost-advantages-and-retrocommissioning-opportunities/

[@jaytulley]

If you want PID control explained in a slightly different way, check out th-cam.com/video/JEpWlTl95Tw/w-d-xo.html

[@rcxuniversity1977]

There's more we could say about control signals, here's a blogpost on why we use 4-20 milliamp signals in our control loops: av8rdas.wordpress.com/2009/04/04/4-20-milliamp-current-loops-why-use-them/