Optimization of fan array in air handling unit

Abstract

An HVAC system is responsible for the ambient control of air temperature and ventilation. It consists of a multiple sub-system. One of them is the air handing unit or AHU, it’s responsible for the air ventilation of a building. It’s a single fan or a fan array in the AHU. It is an important element to force air along the system. In this component most of the systems consist of a single fan but nowadays the use of fan arrays are increasing. Even though the fan array consumes more power and energy than a large single fan, it offers better continuity and distribution of air flow along the system. According to the U.S. Energy Information Administration report on commercial buildings, 16 percent of the electricity is consumed in the ventilation process. Therefore, optimizing the fan array is significant for energy saving. The study uses a fan model created from the manufacturer with the specifications of the fan’s performance graph curve using the aerodynamics and physics of the fan’s velocity laws. However, the model has fan speed limitations. Every fan in the fan array must rotate at the same speed. Therefore, the simulation can show approximately optimal operating point. Although the study wasn’t done within an air handling unit (AHU). The control design is shown and explained in the last part of this report. The fan array controller is ARM STM32 with a support board. This report describes the initial design of the controller preparing the implementation to a fan array in air handling unit.