I have a dual duct system that the spec calls for the following "mix hot and cold deck to maintain room setpoint. On a call for cooling modulate hot deck closed to 50% of total air quantity, on a further call for cooling modulate hot deck closed and cold deck to 50% of total air quantity. On a further call for cooling modulate the cod deck to 100% open."
The boxes are modulating to 50 and 100% like it asks but where does the mixing start. These are invensys controllers, is it possible to " mix the air to maintain setpoint " with out a discharge air temp sensor.
If any of you read this spec how would you program the boxes to operate.