Main Components; Indoor Unit - Emerson Liebert PEX Series User Manual

1.4 Main Components

The main components of Liebert.PEX air conditioner include indoor unit, outdoor unit and iCOM controller.

1.4.1 Indoor Unit

The indoor unit of the Liebert.PEX air conditioner includes compressor, evaporator, thermal expansion valve, infrared
humidifier, fan, electric heater, sight glass and filter drier. Besides these components, the water-cooled series indoor
unit also includes BPHE and electric valve.
Compressor
The highly effective Copeland scroll compressor is used, featuring low vibration, low noise and high reliability. The
Rotalock connection mode makes the maintenance easier.
Evaporator
The finned tube evaporator with high heat dissipation efficiency is used. The distributor is designed and validated
according to specific model to ensure that the refrigerant is distributed evenly in each loop, improving the evaporator
efficiency to a great extent.
Thermal expansion valve
The external equalizer type thermal expansion valve is used. It can collect temperature and pressure signals at the
same time, so that it can regulate the refrigerant flow more accurately.
Infrared humidifier
The infrared humidifier is designed with a simple structure, which is easy for teardown, cleaning and maintenance.
Application of the infrared humidifier can reduce the dependence on water quality. It also features fast startup, short
humidifying time, large humidifying capacity and high humidifying efficiency.
Fan
The forward centrifugal fan with high efficiency and high reliability can be used. It features large airflow, long blowing
distance, belt transmission and convenient maintenance. Users can also select the EC fan, which features high
efficiency, energy-saving, space-saving and low noise. EC fan unit uses elaborate structure design, and the downflow
unit uses the 'in-floor' design, which positions the fan unit below the floor to further improve the efficiency of air supply.
Electric heater
The spiral fin U-type stainless steel heater is used. It features fast heating speed and even heat.
Sight glass
The sight glass is the window of the system cycle, for observing the refrigerant state, mainly the moisture content of
the system. When the moisture content exceeds the standard, the color will be changed.
Filter drier
The filter drier eliminates the moisture effectively in the system, and also filtrates the impurities generated during the
long-term system operation so as to ensure normal system operation.
BPHE (for water-cooled series)
The brazed plate auto-cleansing BPHE is used. It features compact structure and high heat exchanging efficiency.
Rotalock connections are provided for water and refrigerant sides.
Electric valve (for water-cooled series and chilled water system)
Water-cooled series: The precise electric valve is used. The water flow in the BPHE can be regulated through the
intelligent valve position control of the control board, so as to ensure stable system operation.
Chilled water system: The electric valve provides proportional regulation of chilled water flow according to the cooling
requirement.
Union mode is used to connect the electric valve to the system pipeline, which is convenient for installation at site and
maintenance, reducing the project installation expenses.
Liebert.PEX2 Series Air Conditioner User Manual
Chapter 1 Overview 3