Effect of Inlet Duct and Damper Design on Fan Performance and Static Pressure Measurements (ASHRAE RP 1743)
air handling unit, split system
ASHARE and AHRI provides various standards for designing a test setup for HVAC systems, but none of those specify sufficient details for the inlet ductwork design. The purpose of this study is to develop an inlet duct design guideline for inclusion in the AHRI and ASHRAE testing standards which may reduce the risk of false testing failures and will lead to higher integrity of the testing results at different laboratories. This study will evaluate the performance of the fan of the indoor air handler of split systems for various design parameters including the fan and motor type of the air handling unit, inlet duct and damper configurations and air flow rate through the unit. Fan power consumption and air flowrate of the system are to be determined for a range of static pressures for different inlet duct/damper configurations. The test plan includes indoor air handlers of 1.5-ton, 3-ton and 5-ton capacity. For the air handling unit’s three types of motors and two types of fans are considered. Static pressures will be measured between the inlet and outlet of the air handler.Finally, the experimental results will be used to validate CFD simulations of the inlet ductwork.