Understanding the Difference: Air Handler vs Air Conditioner
Most homeowners use "air handler" and "air conditioner" interchangeably when discussing HVAC systems, but these components serve different functions. While they often work together, understanding their distinct roles is important. An air handler (AHU) is an indoor unit that circulates, cleans, and conditions air using fans and coils. An air conditioner (AC) removes heat from indoor air using refrigerant, typically in an external unit. Together in split HVAC systems, they provide optimal climate control.
What is an Air Handler?
An air handling unit (AHU) is the indoor component of many HVAC systems. This large metal enclosure contains a blower (fan), evaporator coils, filters, dampers, and other components that regulate and distribute air throughout a space.
How It Works
- Draws air in through return ducts
- Filters air to remove dust and allergens
- Passes air across cooled or reheated coils
- Distributes treated air through supply ducts
Air handlers may use single-speed or variable-speed motors, with variable-speed models offering better efficiency, quieter operation, and more consistent comfort.
What is an Air Conditioner?
The air conditioner is typically the exterior condenser unit in a split system. Its primary function is removing heat from indoor air and expelling it outdoors. The AC doesn't circulate air itself—it relies on the air handler for distribution throughout the home.
How It Works
- Warm indoor air passes over the evaporator coil via the air handler
- Refrigerant absorbs heat and converts to low-pressure gas
- Compressor converts refrigerant to high-pressure gas
- Outdoor condenser releases heat to the environment
- Refrigerant cycles back inside to continue cooling
Key Differences Between Air Handlers and Air Conditioners
Purpose and Role
- Air Handler: Distributes air throughout your home. It doesn't generate cooled or heated air but works with other systems to circulate conditioned air.
- Air Conditioner: Cools air by removing heat. Produces cooled air that the air handler distributes.
Components
- Air Handler: Contains blower fan, filters, heating elements (electric coils), and dampers. May include built-in humidifiers.
- Air Conditioner: Includes compressor, condenser coil, expansion valve, and evaporator coil. Operates through refrigerant phase changes.
Function
- Air Handler: Conditions and circulates air, providing filtration, heating, cooling, and humidification as needed.
- Air Conditioner: Primarily removes heat and reduces humidity, focusing on cooling in warm climates.
Operation Requirements
- Air Handler: Requires conditioned air supply (from furnace or cooling coil), electrical power for the fan, and ductwork for air distribution.
- Air Conditioner: Needs electrical power for the refrigerant cycle and space for outdoor components.
Location
- Air Handler: Installed indoors in basements, closets, or mechanical rooms. Commercial units may be roof-mounted.
- Air Conditioner: Outdoor installation for central systems, with indoor components integrated into the air handler in split systems.
Size and Installation
- Air Handler: Available in various sizes from residential to large commercial scale.
- Air Conditioner: Sized according to cooling load requirements. Central systems require outdoor space and ductwork integration.
When to Use Each System
Home Cooling Needs
- Homes requiring summer cooling typically need both an air conditioner and air handler
- The air handler ensures even distribution of cooled air through ductwork
Commercial and Large Buildings
- Air handlers manage complex air distribution, filtration, and climate control across multiple zones
- Commercial systems often incorporate specialized filters, humidifiers, and heaters
Combined Systems for Optimal Comfort
- Most HVAC systems combine both components
- The air handler circulates and conditions air while the air conditioner provides temperature control
- This integration delivers comprehensive climate management and improved air quality
Conclusion
Understanding the distinct roles of air handlers and air conditioners is crucial for effective HVAC system design. While air handlers circulate and condition air within a building, air conditioners focus on cooling by removing heat. Most modern systems combine both components to deliver optimal comfort, air quality, and temperature regulation for both residential and commercial spaces.
For professional guidance selecting the right HVAC system for your needs, contact Superior Air Management (Athens, GA).
Contact Superior Air Management today for expert HVAC advice and installation services.
