B051 Ventilation energy benchmark

Energy benchmarks for ventilation systems in air-conditioned offices

Brief:

Indoor environmental quality (IEQ), subjective satisfaction of occupants and energy conservation of buildings are usually determined separately. Since the energy crisis in 1973, engineers have endeavored to implement energy conservation in buildings. Unfortunately, the effort resulted in energy savings without the fundamental delivery of indoor satisfaction in many cases. It is worthwhile to determine a balance strategy between the potential energy saving and occupants’ satisfaction in workplaces. Ventilation system is characterized to be one of the most significant components in annual energy consumption. This study, which based on field measurement and questionnaire survey in 38 sample offices, with ‘acceptable’ temperatures and CO₂ concentrations were used to examine the energy consumption of annual thermal and ventilation system in Hong Kong. An energy benchmarking model that related the major acceptable indoor parameters to building thermal energy consumption was established. The results showed that the energy consumed by a ventilation system would correlate closely with the occupant generated carbon dioxide (CO₂) concentration maintaining in the space, but its correlation with the air temperature set point would be less significant. The energy benchmarking model would be useful for evaluating energy performance and promoting sustainability in buildings without any comfort penalty to the occupants.

Further Information:

Mui KW, Wong LT, Chan WY, Law LY, 2007. Energy benchmarks for ventilation systems in air-conditioned offices, The 6^th International Conference on Indoor Air Quality, Ventilation and Energy Conservation in Buildings, 28-31, Oct, Sendai, Japan. Proceedings Volume 3, pp. 417-423.