air handler

Air Handler

An air handler, or air handling unit, is the indoor part of an air-conditioning or heat pump system. Air handlers work much like furnaces in that they efficiently move air throughout the home. The main difference is that the air handlers only circulate heat when paired with a heat pump. 

Different types of motors 

Like furnaces, air handlers use a blower motor and fan to move conditioned air throughout the ductwork of your home. Lennox offers air handlers with either a variable-speed or single speed blower motor:  

Variable-speed motors provide the highest level of comfort and energy efficiency. They can operate at high speeds, low speeds and anywhere in between, fine-tuning airflow based on demand.  

Single-speed motors operate at full capacity only and cycle on and off as needed to maintain your set household temperature.  

Small air handlers, for local use, are called terminal units, and may only include an air filter, coil, and blower; these simple terminal units are called blower coils or fan coil units. A larger air handler that conditions 100% outside air, and no recirculated air, is known as a makeup air unit (MAU) or fresh air handling unit (FAHU). An air handler designed for outdoor use, typically on roofs, is known as a packaged unit (PU), heating and cooling unit (HCU), or rooftop unit (RTU). 

Larger air handlers will be manufactured from a square section steel framing system with double skinned and insulated infill panels. Such constructions reduce heat loss or heat gain from the air handler, as well as providing acoustic attenuation.[2] Larger air handlers may be several meters long and are manufactured in a sectional manner and therefore, for strength and rigidity, steel section base rails are provided under the unit. 

Filtration is typically placed first in the AHU in order to keep all the downstream components clean. Depending upon the grade of filtration required, typically filters will be arranged in two (or more) successive banks with a coarse-grade panel filter provided in front of a fine-grade bag filter, or other “final” filtration medium. 

Major manufacturers 


Carrier Corporation (also makes Bryant and Payne brands) 

CIAT Group 

Daikin Industries (also makes McQuay International, Goodman, and Airfel brands) 

Emerson Network Power 

Johnson Controls (also makes York International brand) 

Lennox International 

Rheem (also makes Ruud) 


Dragon Air Services is a family-owned business located in the heart of Plano. We specialize in residential Air Conditioning and Heating repairs, Air Conditioning, and Heating replacements, and Air conditioning and Heating service. Our expert technicians pride themselves on providing honest diagnostics so our customers can make educated decisions on what’s best for them. If you are in need of replacing an HVAC unit in Dallas, Plano or surrounding cities call us today at 214-790-9872 to schedule an appointment.  

Here’s the list of services we provide in Plano and Collin County  

AC repair  

AC Replacement  

AC Installation  

Heater Repairs  

Heater Replacements  

Heater Installation  

AC and Heater Preventative Maintenance Furnace Repair  

Furnace Replacement  

Furnace Installation  

Duct Replacement  

Duct Design