Trane TRG-TRC014-EN manual Small Buildings, Changeover/Bypass VAV System, System Configurations

period three

System Configurations

notes

Typically, either VAV reheat or fan-powered terminal units are used to provide the tempering needed to balance the reduced cooling load.

Small Buildings

Figure 65

Changeover/Bypass VAV System

Many smaller buildings cannot afford commercial, or applied, equipment. Often constant-volume, light-commercial equipment, like a small packaged rooftop unit, will be used.

Nevertheless, it may still be desirable to accommodate many independently controlled spaces economically. For these applications, a special VAV system called a changeover/bypass VAV system is available.

Changeover/Bypass VAV System

EA

RA

	bypass damper
OA	supply PA
	fan

	VAV
constant-volume supply fan		SA
VAV to spaces

Figure 66

Like a typical VAV system, a changeover/bypass VAV system contains an airflow-modulation device for each individually controlled space. This device modulates supply airflow in response to the space load. Instead of modulating the central supply fan, however, this system supplies constant primary airflow.

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