METHOD FOR OPERATING AIR-CONDITIONER

PURPOSE:To reduce noise generated from an air-conditioner when quietness is required as at midnight or early in the morning by setting the upper limit of the number of revolution of an inverter-driven compressor according to the time. CONSTITUTION:A room temperature A, a blown-off air temperature B, a set temperature F and a time T from a clock 11 are inputted to a controller 10. Then, the temporary number of revolutions R0 of an inverter-driven compressor is calculated from a function determined in advance according to a difference between A and F and the temporary number of revolutions R1 of the inverter- driven compressor is calculated from a function determined in advance according to B. R0 and R1 are compared with each other. When R0 is smaller than R1, R2 is calculated and, when R0 is larger than R1, R2 is calculated again by inputting R1 to R0. By repeating a similar calculation on T, temporary number of revolutions R5 is obtained and a finally obtained number of revolutions RD is indicated to the inverter-driven compressor 4 from the controller 10. Thus, noise generated from an air-conditioner can be maintained at a low level according to a time.