This paper is based on findings resulting from ASHRAE Research Project RP-1292.

Variable Air Volume (VAV) systems are commonly used to maintain space comfort in commercial buildings. Single-Duct VAV (SDVAV) systems often use Fan-Powered Terminal Units (FPTU) to control the amount of conditioned air that is delivered to a zone to maintain space conditions. A model was developed to evaluate the operation of a SDVAV system using Series and/or Fan Powered Terminal Units. The procedure used to model the system is described in this paper as are the equations used to model all non-zone level components in the system. The SDVAV system model was verified in the laboratory using a test stand that supported the operation of a three zone system using both series and parallel FPTU. The test stand was set up to mimic the operating points as predicted by the model. System operation was measured and then compared to the predicted values. The details of the model verification are described in another paper.

Units: Dual