Energy consumption analysis under demand-controlled ventilation due to drift of indoor air quality sensor

Demand controlled ventilation (DCV), by using indoor air quality (IAQ) sensors to monitor CO 2 concentration so as to adjust the air ventilation mode, may achieve significant energy saving compared with traditional constant volume ventilation. The performance of IAQ sensors is the key factor which directly affects the measurement of CO 2 concentration with linkage to energy consumption. Taking a seminar room under DCV as the example, NMC has conducted the analytical analysis to calculate the energy consumption due to IAQ sensor drift. The details on the analytical method will be presented in this study. The calculation results showed that the energy consumption is in nearly linear proportion to the sensor drift in the range of 5 %–25 %. The sensor drift impact on energy consumption can be affected by the capacity; with larger energy waste at higher capacity and lower energy waste at lower capacity. For the three categories of capacities considered in this study (the full capacity of 91 people, the intermediate capacity of 61 people, and the low capacity of 31 people), the energy waste respectively ranges from 1.93 % to 21.07 %, 1.49 %–19.59 %, and 0.88 %–16.28 %, with sensor drift from 5 % to 25 % under each category.