Abstract
The Active Energy-saving Control System for Air-Conditioning (hereafter called "AECS-AC") was introduced to an office room where there were multiple indoor air-conditioning units and the results of verification experiments conducted in summer and winter with a focus on the thermal environment and the temperature adjustment actions of the people in the room were analysed. This system reduces deterioration of room conditioning by sensing when the occupants switch the air conditioning on and off. Ultimately, the system should satisfy the thermal comfort requests of occupants by feedback of their adjustment behaviour, rather than by collecting the occupants' attributes, thermal and comfort sensations, and psychological conditions.
The main results are as follows.
1) In summer (Jul.-Sep.), AECS-AC was conducted at a pre-set temperature of 26°C in an office room with multiple indoor units, which were alternately grouped into two. After the air conditioning mode was stabilized, the mean room temperature was maintained at 26-28°C irrespective of the outdoor temperature. The temperature variation at the sensor positions due to the start-stop operations of the indoor units was 1-1.5°C and the room temperature variation across the office room was about 2-3°C.
2) In winter (Dec.-Feb.), AECS-AC was conducted at a pre-set temperature of 22°C in an office room with multiple indoor units, which were alternately grouped into two. After the air conditioning mode was stabilized, the mean room temperature was maintained at 22-25°C irrespective of the outdoor temperature. The temperature variation at the sensor positions due to the start-stop operations of the indoor units was 1°C and the room temperature variation across the office room was about 2°C.
3) In the air-conditioning control according to the number of occupant's switching-on/off actions, the AECS-AC followed the change in the thermal environment caused by the influence of the outdoor temperature.
4) The number of manual switching-on/off actions varied from place to place in the room and differed between the perimeter side and the interior side. The occupant's preference on the thermal environment could be deduced from their air conditioner adjustment actions.
5) According to the questionnaire results in winter, almost neutral air-conditioning control could be realized for the occupants based on their answers that 60-80% were neither hot nor cold. Regarding comfort evaluation, about 50% of answers of “comfortable” and “slightly comfortable” were accounted, and it went up to about 80-90% if including the answers of “neither of them.”
The above results show that the AEC-AC based on the number of people's air conditioning adjustment actions realized air-conditioning control appropriately to the thermal environment of an office room with multiple air conditioners.
Furthermore, the possibility of personal-like air-conditioning realization was shown by controlling an indoor unit individually.
