9 – AIR-HANDLING PROCESSES

This chapter describes the fundamentals of air handling processes and equipment and answers to questions related to the theoretical background of air handling unit and ductwork dimensioning and building energy systems optimization. It deals with the basic air-handling processes: filtration of particles and gaseous substances from the supply and recirculated air, air heating and cooling, heat-recovery processes, and humidification and dehumidification; equipment space requirements, associated components, and the pressure losses of various components, good design practices, including system balancing and efficient running; and essential factors in the selection of systems and equipment during the design stage. On the system level, considerable efforts have been made to reduce the heating and cooling demands, and the electrical energy consumption has been regarded as a marginal part. In ductwork design, attention must be paid to reduce energy losses using properly designed fittings and proper duct sizing.