| Name | Vav_terminal_unoccupied_setback |
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| Display Name | Vav Terminal Unoccupied Setback |
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| uuid | f3a1b2c4-d5e6-4789-abcd-012345678901 |
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| Type | Measure |
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| Language | Ruby |
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| Tags | HVAC.HVAC Controls |
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| Description | For a selected thermal zone, applies unoccupied setbacks: (1) derives the
occupancy schedule via Space → Space Type → People, creates a modified
airflow turndown schedule, and assigns it to the zone's VAV terminal; (2)
finds the zone thermostat DualSetpoint, clones the heating and cooling
setpoint temperature schedules with setback temperatures substituted during
unoccupied periods; (3) finds the zone ZoneControlHumidistat, clones the
humidifying and dehumidifying setpoint schedules with setback humidity
values substituted during unoccupied periods. Setting a setback value to 0
skips that setback entirely. The measure can be used to model ASHRAE 170
healthcare setbacks. |
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| Modeler's Description | OpenStudio Measure: Occupancy is resolved from Space (in zone) → SpaceType
→ People → Number of People Schedule. The turndown schedule
(ScheduleRuleset) is cloned from the occupancy schedule with occupied values
(> 0.1) → 1.0 and unoccupied values → turndown_fraction. Temperature and
humidity setback schedules are cloned from the existing setpoint schedules;
each day profile is merged with the corresponding occupancy day profile so
that unoccupied periods (occ ≤ 0.1) receive the user-specified setback
value. Rules are matched by index (rule[i] of temp schedule paired with
rule[i] of occupancy schedule); falls back to the occupancy default day if
the occupancy schedule has fewer rules. New schedules are named
'_Minimum Air Flow Turndown Schedule' and
'__Setback'. Setting any setback argument to 0
skips creation of that schedule. Humidity setback requires
ZoneControlHumidistat. Supports AirTerminalSingleDuctVAVReheat,
VAVHeatAndCoolReheat, VAVNoReheat, VAVHeatAndCoolNoReheat,
AirTerminalDualDuctVAV, and AirTerminalDualDuctVAVOutdoorAir. Warning: The
measure will overwrite design day schedules. If equipment is autosized, this
may resize equipment capacities. If this measure is being run on existing
equipment it is recommended to hardsize the equipment first. Implementing
setbacks on existing equipment not originally sized for setback may
encounter shortages in capacity. |
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| Measure Function | Measure |
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| Requires EnergyPlus Results | false |
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| Uses SketchUp API | false |
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| Measure Type | ModelMeasure |
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| OpenStudio Version | 3.10.0 |
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| Minimum Compatible OpenStudio Version | 3.0.0 |
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| GitHub Repo Link | View on GitHub |
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