Quote Originally Posted by SensibleHeatUK View Post
That said, in my time in comercial building controls I never once saw a system get its control loops tuned, most commissioning engineers simply picked their favourite values and put them into their code and hoped for the best!
I can't speak for most, but I certainly did (although typically the logic would just be PI on the stuff I worked with and wrote). You've have a good idea of starting values, but as you say it could be very site specific and setting things too tight could cause instability. Lot of delays of all sorts in a typical heating system!

By the way, you say "in your time" .. was that by any chance back in the '80s before the bottom fell out of the energy management and energy saving market?