Renewable energy is the focus of the 5th Strategic Energy Plan in Japan. Electric load management systems such as Demand Response (DR) are necessary to increase renewable energy usage. The focus of this study is pre-cooling operations in the daytime, during summer, to reduce electric load during DR. The aim of this study is to evaluate (1) the effectiveness of electric demand shift by “Pre-cooling”, and (2) the effect on comfort and health of the residents who switch to “Pre-cooling”.
The following observations are reported in this article.
1) With regard to the thermal environment, the PMV is about 0.5, and the WBGT is lower than 25oC, which is the temperature of heatstroke warning at the end of the DR. Hence, even if the air conditioner is stopped during DR, it is possible to maintain thermal comfort and health by pre-cooling.
2) With regard to the energy evaluation, the energy consumption of case 3 (DR_OFF), without the air conditioner during DR, was reduced by about 0.4 kWh compared to case1 which is operated at 25oC constant. However, the energy consumption of case 3 (DR_OFF) increased by about 1.2 kWh when the air conditioner was restarted after DR. For case 2 (DR_27oC), where the set temperature was raised to 27oC during DR, the reduction in energy consumption during DR slightly reduced compared to case 3 (DR_OFF), but it was shown that the energy consumption after restarting the air conditioner could be reduced.
3) With regard to the subjective evaluation of occupant behavior during the pre-cooling operation, there was no significant difference between case A and case B in the report for the whole-body thermal sensation. However, case A, in which the occupant behavior was aimed at DR adaptation, reported significantly higher comfort in the thermal environment and thermal satisfaction during DR. The air conditioner stop time during DR of case A was extended by 35 minutes over case B by matching the housework time to the pre-cooling time zone. This showed that case A could provide comfort for 35 minutes more than case B when the air conditioner was stopped.
4) With regard to the physiological evaluation of occupant behavior during the pre-cooling operation, subjects in case A showed less stress than case B for LF/HF and SDNN. Even in a hot environment with the indoor temperature at 27oC, the LF/HF value for case A was significantly lower, whereas that for case B was over “2” which indicates stress. It was thus shown that occupant behavior by matching the housework time to pre-cooling time zone may suppress stress due to indoor temperature rise.
抄録全体を表示