Split System air conditioning units use a compressor, condenser and evaporator to pump refrigerant fluid through a heat exchange process. However, unlike the layout of a conventional cooling unit, the components of a Split System are not self-contained in a single condensing unit.
Residential central air conditioning or heat pump systems typically feature a Split System design. The condenser and compressor usually makeup the outdoors component of the system. When installed correctly, the external unit is mounted in a shady area free of brush and unnecessary obstructions to air flow. Likewise, the evaporator, blower and ductwork function as components of inside sections of the unit.
The fined coils of the evaporator is typically mounted in the ductwork and downstream of the blower unit. The units are connected via two flexible refrigerant lines. In an energy-efficient design, each of the components is custom-selected to meet the exact physical requirements of each individual home. Refrigerant piping is also custom-fashioned make the best use of the equipment.
Fundamentals of Split System Operations
In any Split System heat pump or air conditioning layout, two fundamental processes are involved:
1) Some form of refrigerant fluid provides the principle cooling power
2) The primary components of the cooling unit, evaporator and condenser, are located in separate physical locations.
Two points mark the distinction between a Split System heat pump and a Split System air conditioner:
1) Heat pumps are capable of reversing the condenser and evaporator functions
2) Being dedicated to cooling only, central air conditioning systems typically provide a better cooling energy-efficiency ratio than heat pumps.
The Components of a Split System
Evaporator: Typically considered the starting junction of the cooling cycle, the evaporator receives high-pressure refrigerant liquid through a thermostatic expansion valve. Due to pressure differences and heat drawn from the surrounding medium of air or water, the liquid within the evaporator boils. Thus the evaporator captures the heat from within the building and transfers it to the refrigerant gas as it leaves the evaporator.
Compressor: In simple words, air conditioning systems transfer indoor heat to the outdoors. Heat pumps can reverse this function. The compressor within the system draws refrigerant gas from the evaporator, performs a compression process on the gas and then releases the compressed gas directly into the condenser. The discharged gas now carriers the heat taken from within the home to the outside world.
Condenser: The air conditioning condenser receives hot refrigerant gas from the compressor and converts it into a liquid. As the final component in the heat exchange link, the capacity of the condenser must be sufficient to handle and reject the heat generated by the compressor as well as the collected internal home heat. The typical home Split System uses an air-cooled condenser. However, water-cooled units are also available.
Keeping it all Working
Installation is only the first part of heat pump or air conditioning services. Knowing how it functions helps homeowners better understand the need for a yearly heat pump maintenance program. If your Split System is sized right for your home, installed by a qualified and certified HVAC technician and adequately tested for efficient performance it will last for years and with few breakdowns.