Catalyst RTU Controller Study Report
Sacramento Municipal Utility District
An electronics manufacturer in Rancho Cordova, California installed Catalyst Efficiency
Enhancing Controllers on four package rooftop units (RTU) for evaluation. The Catalyst
controller optimizes outside air intake economizer position and provides variable speed control
to the single (full) speed single zone air handler motor.
The controller, has remote communication which allows real time observation and control of the RTU via the internet. Approximately 10 months of unit performance data are collected, alternating control system modes periodically so that energy savings under on and off of variable speed controls can be calculated. Multiple variable linear regression models of unit power as a function of NOAA weather data and occupancy information are created and applied to Typical Meteorological Year (TMY3) weather data in order to predict typical annual energy savings.