Project Info

Project Title 
Effect of a Variable Speed Drive (VSD) on the Indoor Fan of a Commercial Roof Top Unit (RTU)
Project Number 
PGE 0713
Investor Owned Utilities 
Project Year(s) 
2007 - N/A

Project Summary

This Commercial air conditioning rooftop units (RTUs) are typically implemented as single zone, constant volume systems that cycle in response to a thermostat signal. Much of the energy used by the RTU is needed to power an indoor fan. (Fan power is roughly a function of the cube of the fan speed or airflow.) This project examines the effects and opportunities available from installing a variable speed drive (VSD) on the indoor fan to reduce demand by lowering fan speed. For more information, please contact the sponsoring organization.