Issue link: https://hi.iaq.net/i/630729
124 Appendix B The illustration above shows the general relationship between many of these components; however, many variations are possible. Outdoor Air Intake Building codes require the introduction of outdoor air for ventilation in most build- ings. Most non-residential air handlers are designed with an outdoor air intake on the return side of the ductwork. Outdoor air introduced through the air handler can be filtered and conditioned (heated or cooled) before distribution. Other designs may introduce outdoor air through air-to-air heat exchangers and operable windows. ■ supply fan ■ ducts ■ terminal device ■ return air system ■ exhaust or relief fans and air outlet ■ self-contained heating or cooling unit ■ control ■ boiler ■ cooling tower ■ water chiller The following discussion of these components (each of which may occur more than once in any total HVAC system) emphasizes features that affect indoor air quality. It may be helpful to refer to this section when using the HVAC Checklists. FIGURE B-1: Typical HVAC System Components Courtesy Terry Brennan Camroden Associates Oriskny, N.Y.