sfAhuRulesExt

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)

ASHRAE 55-2013 states velocity 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)

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)

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)

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)