Min Outdoor Air Rate

The minimum outdoor air rate of an air system denotes the lowest limit of outdoor air required during the turn-down of the system. This is often the minimum flow during heating or nighttime operation. If this flow has been determined already, the value can be entered here, else the Autosized setting will cause the simulation to size the value based on the inputs and calculation methodology.

Max Outdoor Air Rate

The maximum outdoor air rate of an air system denotes the highest limit of outdoor air required during the peak of the system. This is often the maximum flow during max occupancy. If this flow has been determined already, the value can be entered here, else the Autosized setting will cause the simulation to size the value based on the inputs and calculation methodology.

Min Supply Air Rate

The minimum supply air rate denotes the lowest limit of airflow an air system can operate at. This is often the minimum flow during heating or nighttime operation. If this flow has been determined already, the value can be entered here, else the Autosized setting will cause the simulation to size the value based on the inputs and calculation methodology.

Max Supply Air Rate

The maximum supply air rate of an air system denotes the highest limit of supply air required during the peak of the system. Typically, this is the maximum flow during max cooling. If this flow has been determined already, the value can be entered here, else the Autosized setting will cause the simulation to size the value based on the inputs and calculation methodology.

Supply Fan Type

This parameter gives the option of choosing between a variable or constant volume supply fan for the air system.

  • A constant air volume (CAV) fan operates continuously based on a time schedule. This fan will not cycle on and off based on cooling/heating load or other control signals

  • A variable air volume (VAV) fan operates over a range of fan speeds and is based off a time schedule, cooling/heating loads, and other control signals.

Relief Fan Type

This parameter gives the option of choosing between a variable or constant volume relief fan for the air system.

Supply Fan Location

This parameter defines how the supply fan is arranged. There are two choices:

  • The Blow-Through choice indicates that the fan is located upstream of the zone equipment

  • The Draw-Through choice indicates that the fan is located downstream of the zone equipment

Relief Fan Location

This parameter defines how the relief fan is arranged. There are two choices:

  • The Return choice indicates that the fan is located upstream of the mixing box. The fan is sized for the return air of the system.

  • The Exhaust choice indicates that the fan is located downstream of the mixing box. The fan is sized for only the exhaust air of the system.

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