Assessment of HVAC system operational fault impacts and multiple faults interactions under climate change
Fangliang Zhong, John Kaiser Calautit, Yupeng Wu
Abstract
The effect of climate change on heating, ventilation and airconditioning (HVAC) system performances has become prominent, and HVAC fault impacts may also vary with climate change. This paper evaluates the impacts of HVAC operational faults on system energy and occupant thermal comfort under the current, 2030s and 2050s climates using a validated model. The energy and thermal comfort impact indicators were proposed to rank single and multiple faults under each climate period. Supply fan stuck at maximum speed, and the combinations associated with this fault were ranked first in energy and thermal comfort rankings, respectively. Based on the investigations of multiple faults interactions, it is found that the synergetic/antagonistic effect of multiple faults combinations can lead to a significantly higher/lower combined impact than any single fault impact among the combination when the single faults present opposite impacts. Moreover, heating coil supply air temperature sensor negative bias, and the combination of thermostat positive offset and outdoor air damper stuck fully open led to the most increase system total electricity by 34.3 GJ and 35.3 GJ from current to 2050s period. The results are useful for researchers to prioritise the faults with significant impacts for developing fault detection and diagnosis framework.