ABSTRACT
This chapter enables the user such as to understand the meaning of static, velocity and total air pressure terms and units, to apply Bernoulli's theorem to air flow in ducts, to calculate and plot graphs of the changes of air pressure that occur at fans. The design procedure for air duct systems is described, from the use of Bernoulli's equation through to a workbook that can be used for duct routes. The chapter also explains following such as to know how to measure air pressure in ducts, to calculate the air pressures used in ductwork design, toanalyse the changes in pressure when air flows through changes in duct size. Laboratory air flow meters for research or frequent tests by a manufacturer of air conditioning components have several diameters of upstream straight duct for flow straightening. The pitot-static tube is used for accurate flow measurements to enable calibration of a venturi or orifice plate meter.
