Enhanced Prioritization – Indoor Temperature Analysis

Applicable Systems

  • Primary: AHU, TRU, MUA, ERV
  • Secondary: HP, FCU, UV, UH

Description / Method

Measures indoor temperature fluctuations during building occupancy to determine Comfort Impact. (Prioritization)

  • Comfort Impact is the number of days (expressed in percent of total days analyzed) that the indoor temperature has exceeded ASHRAE’s accepted operative temperature ranges.
  • A CTL measures the cumulative sum (CUSUM) of the number of days the accepted operative indoor temperature range has been exceeded.

Logic

Enhanced Prioritization – Indoor Air Quality Analysis: CO2 Concentration
  • 1. Control program error. Verify equipment sequence of operations.

Message

Indoor temperature issue. ASHRAE’s accepted operative temperature range has been exceeded. A high comfort impact value means that this condition has been prevalent during the analysis period.

Notes

Source: http://www.nrc-cnrc.gc.ca/ctu-sc/ctu_sc_n64

ConditionsAcceptable operative temperatures
Summer (clothing insulation = 0.5 clo)°C°F
Relative humidity 30%24.5 – 2876 – 82
Relative humidity 60%23 – 25.574 – 78
Winter (clothing insulation = 1.0 clo)°C°F
Relative humidity 30%20.5 – 25.569 – 78
Relative humidity 60%20 – 2468 – 75

Rule Template Type

  • Insight Type: Fault Detection
  • Trigger Type: Active High

Inputs

InputsUnitsDefault ValueTagsDescription
Indoor Temperature [deg] {zone,air, temp, sensor}°C or °F zone,air, temp, sensorIndoor air temperature sensor TL
Highest Acceptable Indoor Temperature [deg]°C or °F25 Maximum indoor air temperature allowed for rule
Lowest Acceptable Indoor Temperature [deg]°C or °F15 Minimum indoor air temperature allowed for rule
Building Schedule  occupiedOccupancy schedule (binary)
Threshold – Maximum Weekly Comfort Impact%15 Weekly threshold to trigger Comfort Impact Insight
Threshold – Max Degrees Out of Range°C or °F5 This value represents the urgency score at 100
Threshold – Maximum Weekly Urgency Score%20 Weekly threshold to trigger Urgency Insight