The bus air conditioning system on bus mainly consists of the compressor, condenser, evaporator, pipeline system and electric-controlled system. For example, Guchen BD-06 model, cooling capacity 32000Kcal/h with the Bock FKX40/655K compressor, its condenser and evaporator are mounted on the top of the bus, the reservoir, filter direr, cut-off valve, sight glass, expansion valve and fresh air device are installed inside the evaporator, the compressor is installed on the side of the engine, and the control panel of the bus air conditioner is installed beside the instrument board. It has its own starting system, and once the bus engine is running, the compressor runs together with it via a magnetic clutch which installed on compressor. LA16.02Y 2B193 Electromagnetic Clutch The rooftop evaporator assembly use the SMC (formerly use the FRP for ordinary buses or aluminum alloy for luxury coach) casing house the evaporator coils. It is an internal thread cooper tube with the hydrophilic aluminum foil in shape where a blower blows the passenger compartment cooled air through the finned coils into the individually arranged ducting going to the individual passenger seat roofing. Air duct are provided for aiding air direction inside the bus. BD Series bus air conditioner The condenser assembly is made of MFC (multi follow condenser) or copper tubing also serpentine in shape with aluminum fins to aide the heat dissipation better. A strong condenser fan blows the air through the condenser tubing, thereby releasing the heat collected by the refrigerant into the atmosphere. When the compressor of the bus air conditioning system is running, it compresses the refrigerant coming from the evaporator into high-pressure and high temperature refrigerant gas. Together with the heat absorbed by the evaporator, the hot refrigerant travels into the condenser unit. FK 40 bock compressor for bus AC system Upon reaching the condenser, the accumulated heat in the gas refrigerant is released into the atmosphere through the condenser fan. Once the heat is reduced the gas refrigerant turns into liquid refrigerant. The liquefied refrigerant now enters the reservoir, where the high pressure refrigerant is stored. It then passes through the filter drier, small foreign materials like dirt, iron particles, and moisture in the refrigerant is filtered and strained. The filter drier contains filter, desiccant, and stop-valves for maintenance removal of the device. The filtered refrigerant now enters the sight glass, a device where you can see the liquid refrigerant travelling into the thermostatic expansion valve. The refrigerant through the sight glass should be like water, and not like small bubbles, because if it is so, it means the refrigerant is under charged. The thermostatic expansion valve controls the flow of the liquid refrigerant into the evaporator. A sensing bulb is attached to the tube prior to the outlet of the evaporator. When the calibrated temperature difference between the inlet and outlet of the evaporator is breached, the valve open and let refrigerant to enter the evaporator, maintaining a constant volume of liquid refrigerant in the coils. When the heat inside the passenger compartment is absorbed by the liquid refrigerant of the evaporator, the refrigerant boils and turns into gas. The temperature and the pressure drops as it enters the compressor, where it is being compressed and the refrigeration cycle repeats. For more information, you can contact us at for consulting. Guchen, the standard solution provider of bus air conditioning system for FIFA World Cup 2010 in South Africa, is the leading bus air conditioning system and transport refrigeration units supplier in China, standard OEM supplier of Yutong Bus and key partner of Shaolin Bus, North Neoplan Bus, Zonda Bus, Yaxing Bus, etc. and the OEM supplier of China top brand manufacturers of refrigerated van/truck. Visit us at for further information.