Packaged Rooftop VAV w/Reheat

Typically used in offices and commercial type buildings. This type of system is also called sometimes Packaged Rooftop System or RTU (Rooftop Unit) or System 5 (per ASHRAE 90.1 HVAC mapping).

System typically have mixing plenum with outside, return and bypass air dampers, air filters, DX coil, heating coil (gas, hot-water or electric), variable flow supply fan. Air is supplied to the zones via VAV boxes. For each zone branch there is a reheat coil. VAV system can be used to model  CV system by turning the Minimum Turndown Ratio to be 1.

Default values:

  • VAV Box damper heating reaction: reverse
  • No Baseboard heating
  • Hot Water Pump power: 21 W/gpm or 1.32 W/(L/s)
  • RTU Fan Power: 1.64 W/cfm or 0.778 W/(L/s)
  • Hot water pumps are VSD
  • Night time operation: Cycle on any load
  • No humidifier
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