Central AC Parts


The split-system central air conditioner is segmented into indoor and outdoor component parts, assemblies and configurations.   These work together to control cooling and maintain air circulation.   The most commonly used parts or assemblies are listed below: 

Indoor Parts

air handler

The air handler assembly contains several internal parts responsible for funneling cool air through your home. 

evaporator coil

Cooling coils remove heat and humidity from air using freon or refrigerant.

drain lines

The drain line runs from the air handler to the outside of the home near the compressor.  Blockages are common, leading to dripping water inside the home. 

blower fan motor

The blower fan motor circulates air over the evaporator coils, producing a chilling and cooling effect in your home. 

air filters

The air filters captures dust particles and debris, preventing it from clogging up parts inside the air handler. 


This programmable device helps control and regulate the temperature within a home. 

float switch

If the drain line above gets clogged, this switch trips the system , shutting down the central AC unit. 

circuit boards

Tasked with electrical trip switches for the indoor air handler system. Circuit breakers may trip and shut down AC  if unit has systemic issue. 

Outdoor Parts

Condensing unit

The condensing unit is the outdoor cabinet containing the various parts including compressor and fan motors. 


The heart of pump of the central ac system, it helps circulate refrigerant through the coil system. 

ccondenser fan motor

The condenser fan motor helps expel heat from the system into the outdoor environment. 


A mechanical relay in the circuit board responsible for switching between low and high voltage in unit. 


Similar to a starter motor in a car, the capacitor kickstarts the compressor and fan motor into action. 


Yes, in fact that a reader will be distracted by the readable content of a page when looking at its layout.

ddisconnect box

This resides on the outside wall near the compressor.  It contains a cartridge which can be removed to cut power to the condensing unit. 


The cartridge contain fuses essential for electrical operations in the outdoor central AC components. 

Maintaining & Replacing Parts in Central AC System

The shelf life of parts and the central air conditioning unit listed above vary according to brand, model, location and home environment. As a general rule of thumb modern day AC systems should function, if well maintained, for around 8-10 years. 

However, several parts may need to be replaced over this period including capacitors, fan motors, contactors and thermostats.

 These parts can be repaired, replaced or re-ordered through reputable HVAC contractors such as Air Pros which provides financing and services manufacturer warranty agreements.   To ensure a longer lifetime for individual parts, it’s essential the homeowner consider robust annual preventive maintenance plans offered by air conditioning contractors.  

Annual inspections and diagnostics pin point systemic issues with air flow and home configurations, while also identifying parts that may need to be fixed or replaced. 

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