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

Conditions Acceptable operative temperatures
Summer (clothing insulation = 0.5 clo) °C °F
Relative humidity 30% 24.5 – 28 76 – 82
Relative humidity 60% 23 – 25.5 74 – 78
Winter (clothing insulation = 1.0 clo) °C °F
Relative humidity 30% 20.5 – 25.5 69 – 78
Relative humidity 60% 20 – 24 68 – 75

Rule Template Type

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

Inputs

Inputs Units Default Value Tags Description
Indoor Temperature [deg] {zone,air, temp, sensor} °C or °F   zone,air, temp, sensor Indoor air temperature sensor TL
Highest Acceptable Indoor Temperature [deg] °C or °F 25   Maximum indoor air temperature allowed for rule
Lowest Acceptable Indoor Temperature [deg] °C or °F 15   Minimum indoor air temperature allowed for rule
Building Schedule     occupied Occupancy schedule (binary)
Threshold – Maximum Weekly Comfort Impact % 15   Weekly threshold to trigger Comfort Impact Insight
Threshold – Max Degrees Out of Range °C or °F 5   This value represents the urgency score at 100
Threshold – Maximum Weekly Urgency Score % 20   Weekly threshold to trigger Urgency Insight