Indoor Thermal Conditions And Occupant’s Behavior In Office Space Of Engineering Design Institute In Chongqing

Along with the on-going growth of building energy consumption,public buildings which occupy the 40% percent of building energy consumption have been given priority in recent national energy saving efforts.The distribution of operation energy consumption in office buildings is rather dispersed,the main reason for which is the diversity of occupant’s behavior.Influenced by environmental factors,occupant’s behavior is also related to their work schedule and personal habits.This research focus on the specific working environment and schedule for designers who work in the office buildings of designing institutes,and their behavior with window and air conditioner were studied through questionnaire,field measurements and simulation.A more realistic occupant’s behavior model is built so as to assisting the research of energy consumption difference and energy efficiency potentiality in office buildings.First,the survey on 10 office buildings of designing institutes was conducted and questionnaires were obtained from 237 designers.The indoor thermal comfort and occupant behavior in the office area with centralized air conditioning system and distributed air conditioning system were compared.Second,field measurements are conducted in three office buildings to record window opening and air conditioner use in summer,autumn and winter respectively as well as indoor thermal conditions(temperature,humidity,CO2 concentration).Data about staff’s activity status such as occupancy,steps and heat rate were collected through wearable sensors.Compared with other work patterns(executive,sales,manager),the designers are distinguished for a longer occupancy time and higher energy demand.Third,factors which influence occupant behaviors significantly were collected by using logistic regression and models of window opening and operation of air conditioner were built.It proves that occupants’ operation of air conditioner is closely related to outdoor temperature,and the probability of switch-on the air conditioner goes up with the temperature and remain steadily at 0.8 when the outdoor temperature increase to 35℃.Indoor CO2 concentration has impact on occupant behavior by exerting an upward shift to the probability curve when it rises.In the non-air-conditioning condition,the indoor and outdoor temperature difference is the main factor which influences occupants’ window behavior.In summer air-conditioning condition,indoor temperature has a more significant impact on window opening behavior than outdoor temperature in the office area with centralized air conditioning system.However,in the office area with distributed air conditioning system,the indoor CO2 concentration could also be a driving factor.Finally,based on the typical work schedule of designers,the energy simulation was conducted by using DeST-C software.Compared with other work schedule,some measures of optimizing the performance of heating and air-conditioning were analyzed,such as the increase of ventilation rate,the reform of building envelope and the adjustment on temperature settings.The results show that,these three kinds of measures can realize the energy efficiency rate of 5.3%,9.4% and 22.4% respectively in the office building of designing institute,which is 30%~40% percent higher than in tipical executive working environment.The improvement ideas of thermal environment within office building of designing institute were proposed.