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
Diagnosis / Recommended Action
- 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 |