In the present study, the heating and cooling characteristics of system air-conditioner using a PWM compressor or a BLDC inverter compressor are investigated by the psychometric calorimeter using air enthalpy method. Cooling and heating capacities, power inputs and COPs are measured at the low, moderate, high loads under the cooling and heating standard conditions. At cooling conditions, the capacity of the PWM system is larger than that of the inverter case. Due to large power input, however, low COPs are measured under total load ranges. At heating conditions, the capacity of the PWM method is a little larger than that of the inverter case, except high load range. Since power input is low, large COPs are measured at moderate and high load ranges, which are different from cooling data. This shows that the PW system compared with the inverter case has good energy consumption efficiency at moderate and high load ranges except low load range. And when the system A/C is operated under the cooling and heating standard conditions, COPs are nearly uniform at total load ranges.