sfAhuRulesExt 1.0.3

Run rules against AHUs. Includes some ASHRAE 55 recommendations.

Overview

Welcome to SkySpark's AHU Rules Extension! As of today, there are 5 functions in this package - 3 come directly from ASHRAE 55.

ruleAsh55Rate(theAhu, dates, thresh1: 2.0Δ°F, thresh2: 4.0Δ°F)

ASHRAE 55-2013 states that a zone cannot change by more than 2.0°F in 15min

or 4.0°F in 1hr
  • Side Effects: Converts units to units of thresholds
  • Inputs: 1) An ahu with a zone air temp sensor point
  • 2) a date-range or single day
  • 3) optional - threshold1 (default 2.0Δ°F)
  • 4) optional - threshold2 (default 4.0Δ°F)
  • Output: When temp change is too fast
  • ruleAsh55Rate(read(ahu), yesterday)
  • ruleAsh55Rate(read(ahu), yesterday, 3.0Δ°F, 5.0Δ°F)

ruleAsh55Speed(theAhu, dates, area: 1ft², thresh: 30ft/s)

ASHRAE 55-2013 states flow of < 30ft/sec

  • Side Effects: Converts units to units of threshold
  • Inputs: 1) An ahu with an air velocity or air flow point
  • 2) a date-range or single day
  • 3) optional - duct area (default 1ft²)
  • 4) optional - different threshold (default 30ft/s)
  • Output: When velocity is too fast
  • ruleAsh55Flow(read(ahu), yesterday)
  • ruleAsh55Flow(read(ahu), yesterday, 2ft², 15ft/s)

ruleAsh55Temp(theAhu, dates, theMin: 66°F, theMax: 84°F)

ASHRAE 55-2013 states a range of 66°F to 84°F in a zone

  • Side Effects: Converts units to units of thresholds
  • Inputs: 1) An ahu with a zone air temp sensor point
  • 2) a date-range or single day
  • 3) optional - threshold1 (default 66°F)
  • 4) optional - threshold2 (default 84°F)
  • Output: When temp is extreme
  • ruleAsh55Temp(read(ahu), yesterday)
  • ruleAsh55Temp(read(ahu), yesterday, 70°F, 80°F)

ruleExTrans(thePoint, dates, thresh: 10)

Excessive mode transitions with derivatives (needs sfxCalculusExt)

  • Side Effects: None
  • Inputs: 1) A boolean point
  • 2) a date-range or single day
  • 3) optional - threshold in flips/h (default 10)
  • Output: When a boolean changes states too many times
  • ruleExTrans(read(cool), yesterday)
  • ruleExTrans(read(heat), yesterday, 5)

ruleVavSmall(theVav, dates, thePercent: 98%, theLength: 3hr)

Vav undersized; working too hard for too long

  • Side Effects: None
  • Inputs: 1) A vav with a fan of kind numeric
  • 2) a date-range or single day
  • 3) optional - percent threshold (default 98%)
  • 4) optional - time threshold (default 3hr)
  • Output: When a vav's fan is near full power for too long
  • ruleVavSmall(read(vav), yesterday)
  • ruleVavSmall(read(vav), yesterday, 95%, 2hr)

Please contact [email protected] with any questions.

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