Procedure and Application for Determining the Cold Deck and Hot Deck Airflow in a Dual-Duct System

摘要

This paper introduces an innovative method to determine the cold and hot airflow through a dual-duct variable air volume (VAV) system. The actual building load can be identified based on the calculated airflow and temperature for both the cold and hot deck. The supply fan speed is controlled to meet the calculated load requirement. This new technology will improve the supply fan speed control and save energy. A case study was demonstrated in a commercial building during continuous commissioning practices to improve building operations and reduce energy costs. The room load, airflow rate and system resistance(S)value were recorded continuously. The results show that the supply fan operates at maximum efficiency, saving more than 90% fan power, when this new control method is used.