Explaining the Different Types of Air Handlers: A Beginner’s Guide

If you’re new to air conditioning, it’s easy to get confused about the dozens of heating and cooling equipment your home may need. One unit we don’t often hear about is the air handler, essential in distributing conditioned air from your air conditioning unit to the rest of your home. 

Types of air handlers include central air handlers, terminal units, makeup air units (MAU), and rooftop air units. Essential in every HVAC system, air handlers come in different sizes and have varying applications in residential and commercial spaces. 

Before settling on an air handler for your home or business, it’s important to consider your options carefully. This article breaks down the different types of air handlers and shows those best suited for different residential and commercial properties.

Air Handlers Guide: Types, Features, and Applications

Air handlers are of different types and come with various features, allowing users to customize them for their needs. 

Some features of air handlers include:

  • Adjustable speed settings: Adjustable speed is a prominent feature in modern air handling systems. The feature gives users more air conditioning control. For instance, on a hot day, the fan motor runs at a higher capacity to provide more cooling. A cool day sees the unit’s fan motor running at a lower capacity.
  • Advanced filtration systems: Air handlers are equipped with filtration systems to eliminate dust and other airborne contaminants that could wreak havoc on your interior comfort. Additionally, filters also help prevent dust from reaching sensitive interior components, such as fan motors.
  • Configuration flexibility: Air handlers can fit into virtually any heating and cooling system, depending on their design. For example, terminal units are compatible with the main ductwork. Their core function is to get conditioned air into specific spaces.
  • Sound attenuation: Air handlers can make quite some noise when not equipped with a sound attenuator (or muffler) near the component that makes noise (e.g. fan). A sound attenuator is essentially an acoustic treatment resembling a large metal box with rounded metal baffles along its length.
  • Built-in heating and cooling: Some air handlers feature a heating element and cooling coils. As the conditioned air gets distributed around your home, it may lose some heat due to poorly insulated ductwork. The built-in heating and cooling elements help ensure air is released to specific locations at the desired temperature. 

The air supply air in winter can often drop to below freezing in some areas and/or spike in temperature and humidity during the warmer months. In some air handler models, cool air passes over heating elements or heat exchanger coils before it’s released by your air handler.

Air handlers have various applications, including central office buildings, single-family homes, commercial spaces, and hospitals. It is important to select the correct air handler that meets a particular space’s needs and requirements to ensure optimal performance and energy savings.

Read: 3 Reasons Why Air Handler Is Leaking Water

Types of Air Handlers

Air handlers vary by installation location and purpose in a home’s ductwork. Below are the most common types of air handlers. 

Terminal Units

Terminal units are relatively small air handlers that branch off the main ductwork to supply conditioned air to specific rooms. Like the central air handler, these devices have a blower and air filters to repurify the air before it’s pumped into a room.

Terminal air handlers come in various selections, including single-duct, fan-powered, and dual-duct systems.

Have a Question? Ask HVAC Technician

Click here to use the chatbox to speak with one of our technicians.
No in-home service calls. No appointments.

  • Single-duct air handling units (VAV Boxes): Single-duct air handlers are basic units equipped with a damper to control the volume of air flowing into a room. They work in tandem with the thermostat to offer greater temperature control. When it’s hot, the damper opens wide to allow more cool air; when it’s cold, it adjusts to restrict airflow.
  • Dual-duct dual-fan air handlers: These units have two fans that supply warm and cold air to specific temperature zones through two separate ducts.
  • Fan-powered terminal units: These units use a fan to draw in air from the supply plenum and mix it with air from the central air handler. They are best suited for rooms where noise is a concern, e.g., your living room.

Read: Does Air Handler Have Filter?

Multi-Zone Air Handlers

Multi-zone air handling units are similar to fan-powered terminals because they use fans to distribute cool air throughout a building. However, unlike fan-powered terminals, they are designed for multi-room structures.

Some advanced multi-zone air handlers are designed to cool several spaces simultaneously and can be programmed to distribute air throughout the building at different temperatures based on each room’s needs. To supply a constant stream of conditioned air to each room as required, multi-zone handlers use a series of dampers that distribute the supply air among all the temperature zones.

Read: Which Side Of Air Filter Faces Out?

Rooftop Air Handlers

If you look closely at an apartment building’s rooftop, it’s easy to spot a rooftop unit supplying conditioned air to the building. Such units come as self-contained units with all the essentials of a standard Heating, Ventilation, and Cooling (HVAC) unit, including a refrigerant, heating coils, and a compressor. 

They tap into the building’s ductwork to supply conditioned air to different rooms and are small, compact, and weatherproof to withstand the harsh climate on the roof.

Makeup Air Unit (MAU)

The constant exhaust fan action from your central HVAC displaces a significant amount of air that must be replaced to sustain positive air pressure in your home. 

When exhaust fans remove hot air from your home, it creates a negative pressure zone, which induces a rush of cold/hot unconditioned air through open windows, doors, and tiny cracks. This air could contain allergens and pollutants since it has not been filtered. The solution? Introduce a system that brings in clean, conditioned air.

Makeup air units introduce a fresh supply of clean air that is either hot or cold, depending on your needs. They help create a balanced pressure zone that prevents outside air from entering your home. They’re particularly dominant in commercial and industrial applications but can still be used in residential homes.

Are Air Handlers Necessary?

Air handlers are necessary to improve indoor air quality by filtering out air contaminated with allergens and other pollutants. Filtering is important because polluted air can cause negative health effects, including an increased risk of asthma attacks and other allergic attacks.

Other essential roles of air handlers include:

  • Improved home comfort. Air handlers create conditioned environments that are more comfortable to live in by supplying your home with a constant stream of cool air in the summer and warm air in the winter.
  • Smoke control. Designated smoking rooms could use air handlers to take the smoke out and bring fresh air in.
  • Maintaining stable pressure between spaces. Air handlers help avoid pressure differences, which can contribute to a higher energy bill. A pressure deficit in your home induces a rush of unconditioned air to fill the void left when conditioned air is pushed out of the room by the HVAC’s exhaust fans, adding to your air conditioner’s workload. 

Read: How To Keep House Air Clean?


Air handlers are a key component of any air conditioning system because they help distribute conditioned air around your home. An air handler helps keep your indoors at an optimum temperature by supplying hot and cold air to the needed zones. If you’re unsure which air handler fits your needs, get in touch with an expert for more information!