ABSTRACT
The exhaust fan is typical of a piece of equipment that must be “built up.” The fan itself comes with no controls at all, and must be equipped with controls upon installation. Rooftop units, in the purest sense, are packaged air handlers designed to provide single zone heating and cooling. Heating is typically gas-fired, though it could be electric, and cooling is done by refrigeration, with the entire “refrigeration cycle” integral to the unit. Make up air units are air handling units designed to replace, or “make up” air that’s being exhausted by some exhaust system. Fan coil units consist minimally of a fan and a coil. Built up air handlers can be thought of as “the big brother” to built up fan coil units. Variable Air Volume (VAV) and fan powered boxes are zoning equipment, in the sense that they provide for individual zone control when connected to a VAV air handling system.
