The Heat Recovery Glycol Loop Output Module recovers energy from the exhaust air using a glycol loop. The module can be configured for DA-T, EA-T, or ZN-T control. This module accepts heating and cooling mode inputs, a suitability input, control temperature and setpoint inputs, and limit temperature and setpoint inputs. It has an analog output and a binary output for controlling the glycol valve and a binary signal for controlling a circulating pump. This module also incorporates tracking the overridden value of the actual output object (AO, PAO). The module resets the PIDs to default tuning parameters if the Reset PID Tuning input is not Normal.
This module provides a second output that incorporates lead compensation to control devices. This function attempts to remove some of the dynamics of the control loop. This process results in forward-looking predictions and speeds up controller responses. The effect is similar to adding derivative action to the controller. Lead compensation is incorporated into most zone temperature control processes where oversized or nonlinear valves might be applied. For more information on the Lead Compensator block, see Lead Compensator in the Control category of the Logic section.