Subject to change of the number of operation (thermostat-on) units, capacity, air flow rate, suction temperature, humidity change of indoor units
? Load on total system changes.
? Loads on every indoor machine are different.
Compressor Capacity Control
In order to maintain the cooling capacity corresponding to the capacity of evaporator and load fluctuation, based on the pressure detected by low pressure sensor of outdoor unit (Pe), the compressor capacity is so controlled to put the low pressure equivalent saturation temperatures (evaporation temperature = Te) close to target value.
Superheated Degree Control of Indoor Electronic Expansion Valve
In order to maintain the superheated degree in evaporator and to distribute proper refrigerant flow rate in spite of different loads on every indoor unit, based on the temperature detected by thermistors of liquid pipes and gas pipes, indoor electronic expansion valve is so regulated as to put superheated degree at evaporator outlet close to target value.
• Superheated degree SH = (indoor gas pipe temperature – indoor liquid pipe temperature)
