What is an Air Handler?

If you’re a homeowner, you’ve likely encountered the term “air handler” while dealing with your heating, ventilation, and air conditioning (HVAC) system. But what exactly is an air handler and how does it contribute to maintaining your home’s comfort? Let’s explore the answers to these questions and more, gaining a comprehensive understanding of air handlers, their significance in HVAC systems, maintenance tips, and common problems homeowners face.

The Role of an Air Handler

An air handler is a device that circulates conditioned air throughout your home. This critical component of your HVAC system works closely with your air conditioner or heat pump to distribute cool or heated air. However, an air handler is more than just a basic fan. It houses various key components that contribute to air conditioning, heating, and circulation.

Typically, air handlers are located inside the house, often in the attic, basement, or a dedicated closet space. They are connected to the ductwork that runs throughout your home, enabling the distribution of conditioned air to different rooms.

To truly grasp the role and functioning of an air handler, let’s delve into its inner workings and explore its key components.

Key Components of an Air Handler

An air handler is a meticulously designed machine composed of several key components, each with a unique role in the process of heating, cooling, or circulating air. These components include:


At the heart of the air handler lies the blower or fan. This device is responsible for circulating air throughout your home. By pulling in unconditioned air from various parts of your house, it pushes it through other components for conditioning and then forces the treated air back into your home through the ductwork.

Modern air handlers often feature variable speed blowers that can precisely control airflow, leading to enhanced comfort and energy efficiency.

Evaporator Coil

The evaporator coil is another critical component of the air handler. In cooling mode, the refrigerant flows through this coil and absorbs heat from the air blown over it. By cooling down the air, the evaporator coil contributes to the dehumidifying effect of your air conditioner.

Heating Elements

When in heating mode, the air handler utilizes electric heating elements or heat strips to warm up the air. These heating elements heat up when electricity passes through them, and the blower circulates air over these hot elements, thereby warming it before distribution.

Not all air handlers have heating elements, as it depends on whether your HVAC system uses the air handler for heating or if you have a separate furnace.

Air Filter

Before the air is conditioned, it passes through an air filter. This essential component removes particulates like dust, pollen, and other contaminants from the air, thereby improving the air quality in your home and preventing the accumulation of these particles on other parts of the system.

Air filters should be regularly replaced or cleaned to maintain their efficiency.


Air handlers are equipped with dampers, adjustable plates that control the flow of air within the ductwork. By opening and closing, these dampers can control the volume and direction of air, ensuring the distribution of conditioned air to different areas of your home is balanced.

How an Air Handler Works

Whether your HVAC system is heating, cooling, or circulating air, the air handler plays a crucial role. While the process may vary slightly based on the specific function, the general steps remain the same:

  1. Intake: The blower in the air handler draws in unconditioned air from your home through return ducts, regardless of its temperature, humidity, or particulate content.
  2. Filtration: The unconditioned air first passes through an air filter, which traps dust, pollen, pet dander, and other airborne particulates, improving indoor air quality and ensuring relatively clean air passes through the rest of the system.
  3. Conditioning: After filtration, the air reaches the evaporator coil or heating elements, depending on the system’s mode. In cooling mode, the refrigerant in the evaporator coil absorbs heat from the air, cooling it down. In heating mode, the air is warmed up by passing over the heating elements.
  4. Distribution: Finally, the conditioned air is distributed back into your home through the ductwork, guided by dampers within the air handler to achieve balanced airflow throughout the house.

This cycle repeats multiple times per hour, maintaining your home at the desired temperature and humidity levels.

Types of Air Handlers

Air handlers come in different types, designed to cater to specific needs. The three main types are:

Residential Air Handlers

Residential air handlers are compact and designed for homes and small commercial spaces. They often integrate with an air conditioner or heat pump to form a complete HVAC system.

Commercial Air Handlers

Commercial air handlers are larger and have more complex designs. They are used in office buildings, factories, or any large commercial spaces that require significant heating or cooling. Some commercial air handlers may even have additional components like humidifiers or economizers for enhanced climate control.

Make-Up Air Units

Make-up air units (MAUs) are specialized air handlers used in settings where indoor air quality is crucial, such as restaurants, laboratories, and healthcare facilities. These units not only condition the air but also replace it entirely with fresh outdoor air, ensuring a healthy indoor environment.

Importance of Air Handlers

Air handlers are vital for several reasons:

Improved Comfort

Air handlers help maintain consistent temperature and humidity levels in your home, ensuring optimal comfort regardless of external weather conditions.

Better Air Quality

Air filters within air handlers remove dust, pollen, and other airborne particulates, significantly improving indoor air quality. This is especially beneficial for individuals with allergies or respiratory conditions.

Energy Efficiency

Air handlers play a crucial role in the energy efficiency of your HVAC system. By regulating airflow and effectively conditioning the air, a well-maintained air handler can lower energy bills and reduce environmental impact.

Common Air Handler Problems and Solutions

As with any machine, air handlers can encounter problems that affect their performance. Understanding these issues and their solutions is essential for maintaining an efficient HVAC system. Here are some common problems and what you can do about them:

Clogged Air Filters

Over time, air filters in air handlers can become clogged with dust and particulates, restricting airflow and reducing system efficiency. Regularly check and replace your air filters to ensure proper functioning and prevent ice formation on the evaporator coil.

Faulty Blower Motor

If your blower motor fails, the air handler won’t be able to circulate air effectively, leading to discomfort. Signs of a faulty blower motor include unusual noises, poor airflow, or a continuously running system. Contact a trusted HVAC service provider to diagnose and repair the problem.

Leaky Ducts

Leaky ducts can reduce air handler and HVAC system efficiency. Regular inspections and maintenance can help detect and seal any leaks in your ductwork, ensuring proper airflow and optimal system performance.

Frozen Evaporator Coil

Insufficient airflow or low refrigerant levels can cause the evaporator coil to freeze over, leading to poor performance and potential system breakdowns. Regularly change your air filter and have your HVAC system serviced annually to maintain good airflow and refrigerant levels. If you notice ice on your evaporator coil, turn off your system and contact a professional.

Air Handler Maintenance Tips

To ensure the longevity and efficiency of your air handler and HVAC system, follow these tips:

  • Regularly change your air filter to maintain proper airflow and improve indoor air quality.
  • Schedule annual inspections with a professional to detect potential problems before they cause significant damage.
  • Keep the area around your air handler clean to prevent dust and debris from entering the system, especially if it’s located in a basement or attic.
  • Pay attention to unusual noises coming from your air handler and contact a professional for assistance.
  • Trust the Professionals at Paschal Air, Plumbing & Electric for all your HVAC needs.

Frequently Asked Questions

  • Q: Where is the air handler located?
    A: The air handler is typically located inside the home, often in the attic, basement, or a dedicated closet. It needs to be connected to the ductwork that runs throughout your home.

  • Q: Can I use my HVAC system if the air handler is not working?
    A: Without a functioning air handler, your HVAC system will struggle to circulate air effectively. While the system might still produce warm or cool air, it won’t distribute it properly, resulting in uneven temperatures and discomfort.

  • Q: How often should I replace the air filter in my air handler?
    A: It’s a good rule of thumb to check your air filter once a month and replace it every 3 months. However, if you have pets, allergies, or poor air quality in your home, you may need to replace it more frequently.

  • Q: How long does an air handler last?
    A: With proper maintenance, an air handler can last between 10 to 15 years. However, this can vary based on the unit’s quality, operating conditions, and maintenance.

For all your HVAC needs, including air handler maintenance, repairs, and replacements, trust the Professionals at Paschal Air, Plumbing & Electric. We have the expertise and experience to keep your home comfortable in every season.

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