Since the invention of the air conditioner in 1902, engineers have developed various ways of handling the HVAC process. The evaporator and condenser sections are the two major components of Heating, Ventilation and Air Conditioning (HVAC). This is the case as it applies to Direct Expansion (DX) type systems. At the same time, the indoor air absorbs heat inside the evaporator section. The condenser converts the vapor to a liquid by cooling it down. This section is usually located outside on the roof or on the ground. Because the two sections are located in different areas, this is called a split system.
A packaged unit is when the heating and cooling components are contained in the same unit. This type of system can be beneficial when space is minimal. Many times, this type of HVAC unit is also placed outdoor but can also be installed completely indoor. Connected to both the supply and return air ducts; these operate similar to a central air system. These packaged units can be delivered as both air-cooled or water-cooled systems.
The Refrigeration Cycle
In the refrigerant cycle, the air-cooled or water-cooled liquid goes through an expansion valve and is converted into a vapor. The vapor then absorbs heat inside the evaporator before moving on to the compressor. After the compressor, the vapor then goes to the condenser where the refrigerant is air or water-cooled. The component known as a heat exchanger can be accomplished by way of shell and tube, plate and frame or coil.
To achieve the cooling effect, water is supplied continuously to the system. Sometimes building codes do not permit an HVAC system to be installed outside. In this case, packaged units can be installed as a solution. United CoolAir produces these all-indoor packaged systems. By the way, the self-contained HVAC units and are available with multiple air path configurations.