METHOD FOR SWITCHING COOLING AND HEATING VALVES OF MULTI-AIR CONDITIONER USED FOR COOLING AND HEATING FOR REDUCING NOISES AND VIBRATION OF PIPES

摘要

PURPOSE: A method for switching cooling and heating valves of a multi-air conditioner used for cooling and heating is provided to prevent vibration of a pipe and a refrigerant flow noise due to a pressure difference of the pipe. CONSTITUTION: If power is applied to a random indoor unit, it is judged whether an operation mode of the indoor unit is a cooling mode or heating mode(SP1,SP2). In the case of the cooling mode, a high-pressure valve of a valve connected with the indoor unit is opened while a low-pressure valve of the valve is closed(SP3). In the case of the heating mode, the high-pressure valve of the valve connected with the indoor unit is closed while the low-pressure valve of the valve is opened(SP6). It is judged whether the operation mode of the indoor unit is changed(SP4,SP7). If so, the high-pressure valve and the low-pressure valves are repeatedly switched for predetermined time(SP5,SP8).