This is the second part of a three-part paper on feedforward controllers for laboratory HVAC control systems. The development of a controller for temperature during the cooling sequence is studied. Internal heat generation in the laboratory space is the primary disturbing force that activates this sequence. Additional cooling is provided to offset increased load by supplying additional air into the space. The supply flow rate is increased by first opening the general exhaust damper to increase the total laboratory exhaust flow rate. The laboratory pressure constraint is met first, and this is followed by the control on temperature. The combined feedforward-feedback approach is found to outperform the conventional feedback controller.

Units: Dual