Data Aire dap4 User Manual

100
HGRH: Hot Gas Reheat uses a proportional control valve that is modulated by a
PID algorithm to maintain temperature of the discharge air temperature during
dehumidification. The band setting determines the sensitivity of the algorithm. The
smaller the band, the more the algorithm will try to correct the error. If the band
setting is too low, the system will oscillate by being over-responsive. If the band
setting is too high, reheat may lack responsiveness. Ideally, the band s et t ing
s hou ld be as lo w a s possible without causing oscillation. The Integration time
setting is used to slowly shift the HGRH valve opening to correct the error between
temperature reading and set point. The higher Integral time setting, the slower the
valve will be changed. If the Integral time is set too low the valve may change
quickly, causing oscillation. If Integral time setting is too high, the valve may
become sluggish to change. The Derivative time setting causes a sudden change
in HGRH valve opening to correct the error as a result of a quick change in
measured temperature.

Data Aire dap4 Specifications

General

Brand	Data Aire
Model	dap4
Category	Control Systems
Language	English