Most of Australia experiences a Mediterranean-like climate, characterised by hot, dry summers and mild, wet winters. This makes the use of heating, ventilation, and air conditioning (HVAC) systems a necessity rather than a luxury in the city’s residential, commercial, and industrial environments. At the centre of these HVAC systems is the air handling unit (AHU), a crucial component that greatly influences indoor air quality and climate control.  

In this article, our experts at Independent Air Conditioning Solutions (IACS) delve deeper into the nuances of air handling in HVAC systems, focusing on the role of AHUs, the importance of their proper operation, and their criticality in Australia. 

Deep dive into HVAC systems and air handling units (AHUs) 

Heating, ventilation, and air conditioning (HVAC) systems are instrumental in creating and maintaining a balanced, comfortable, and healthy indoor environment, particularly in the diverse climate we experience in Australia. These intricate systems perform a variety of tasks, including the regulation of indoor temperature, the management of humidity levels, and the improvement of overall air quality. 

To fully appreciate the importance of proper air handling in HVAC systems, it’s essential to understand how these complex systems operate. HVAC systems primarily consist of two units—the outdoor unit, which includes the compressor and condenser, and the indoor unit or the air handling unit (AHU). 

HVAC functionality: creating the ideal indoor environment 

HVAC systems work by circulating, filtering, and conditioning air within the building or space. They pull in outdoor air and pass it through a series of filters to remove dust, allergens, and other pollutants. This filtered air is then either heated or cooled, depending on the temperature settings.  

In addition to temperature control, HVAC systems play a pivotal role in managing indoor humidity levels. In cooling mode, HVAC systems reduce humidity by condensing moisture from the air onto the cooling coil, which is then drained away. During heating, the system can add humidity back into the indoor environment as needed, this is especially important in the dry summers. 

Air handling units (AHUs): The heart of HVAC systems 

The AHU is the indoor part of your HVAC system, often housed within a large metal box, located either in a basement, attic, or specially designed cupboard. This unit comprises essential components, each contributing to the overall efficiency and performance of the system. 

  • Blower or fan: The blower or fan circulates air throughout the building, driving the movement of air that needs conditioning, and distributing the conditioned air via ductwork. It is essential in maintaining uniform indoor temperature and air quality. 
  • Heating and cooling elements:  These parts, namely the evaporator coil and the heat exchanger or furnace, are vital for temperature regulation. The evaporator coil cools the air by removing heat, while the heat exchanger or furnace warms the air, typically via fuel combustion or electric heating elements. 
  • Filter racks or chambers: These hold the air filters within the AHU, which are crucial for maintaining indoor air quality. They trap airborne contaminants like dust and allergens, preventing their circulation in the indoor environment. 
  • Sound attenuators: Sound attenuators, or silencers, absorb sound waves generated by the HVAC system operation, helping reduce noise and ensuring a peaceful indoor environment. 
  • Dampers: Dampers are the ‘valves’ of the HVAC system, controlling airflow through the ductwork. They help regulate and maintain consistent temperatures in different zones of a building, enhancing comfort and efficiency.  

The AHU is directly connected to the building’s ductwork, a network of tubes that carries conditioned air to different parts of the building. The ductwork also carries return air back to the AHU, where it is re-filtered and reconditioned. 

Understanding the essential role of AHUs in HVAC systems helps underscore the importance of proper air handling. The AHU not only ensures comfort through temperature regulation but also significantly contributes to the health and well-being of occupants by enhancing indoor air quality. In the specific climatic conditions of Australia, where temperatures vary dramatically between seasons, the AHU’s function becomes even more critical. 

Why is air handling a critical component of HVAC systems? 

Given Australia’s specific climatic conditions, efficient air handling takes on increased importance. Our hot, dry summers and mild, wet winters present a unique set of challenges for indoor air management. 

  • Health and comfort: Australia experiences sweltering summer temperatures. This makes air conditioning an essential part of everyday life. Without it, not only is comfort severely impacted, but it could also lead to serious health risks, including heat exhaustion and heat stroke. Moreover, properly functioning HVAC systems are a critical defence against dust, pollen, and other airborne allergens common in dry environments, providing relief from respiratory conditions like asthma and allergies. 
  • Energy efficiency and environmental impact: As HVAC systems account for a significant proportion of energy usage in buildings, optimising the operation of AHUs can lead to enhanced energy efficiency. This helps reduce operational costs and contributes to our country’s efforts to reduce greenhouse gas emissions. With the dual pressures of rising energy prices and increasing public awareness of climate change, the role of energy-efficient HVAC systems has never been more critical. 
  • Building integrity and indoor air quality: Proper air handling has a direct influence on the indoor air quality, which can affect the integrity of building materials. Excessive moisture, for example, can lead to mould growth and damage to building structures. In wet winter months, the AHU’s dehumidification function is vital to maintain the correct moisture levels and prevent such issues. 
  • System longevity and cost-effectiveness: Routine maintenance of the AHU can significantly extend the lifespan of the overall HVAC system. Given the substantial investment associated with HVAC installation and replacement, it’s financially prudent to ensure they operate effectively for as long as possible. Regular maintenance can prevent minor issues from escalating into major problems, saving significant repair or replacement costs. 
  • Productivity in commercial spaces: In commercial environments, temperature and air quality have been found to impact worker productivity significantly. The AHU, by ensuring a continuous supply of clean, conditioned air, contributes to a comfortable and efficient working environment. This is especially important in Australia, where high summer temperatures could otherwise impede productivity. 
  • Odour control: Another role of the AHU is to control and reduce odours, enhancing the overall indoor environment. This is particularly important in commercial settings, such as restaurants or healthcare facilities, where odours could become a significant issue. 
  • Noise reduction: Modern AHUs are designed to operate quietly, contributing to a more peaceful indoor environment. This is particularly important in residential buildings and offices, where noise disturbance needs to be minimised. 
  • Regulatory compliance: Proper functioning of the AHU is required to meet building regulations and standards related to indoor air quality and energy consumption. Failure to comply with these standards can result in penalties and potential legal issues. 

By understanding these aspects of air handling, building owners and operators in Australia can appreciate the vital role of the AHU within the HVAC system. It not only provides comfortable temperatures but also contributes to health, productivity, building integrity, and energy efficiency. It’s clear that proper air handling is about much more than just comfort; it’s a necessity for the country’s unique climate and environment. 

Regulatory landscape: ensuring compliance in HVAC systems 

HVAC systems in Australia must comply with the National Construction Code (NCC) and Australian Standards (AS). These codes and regulations are designed to safeguard the safety, health, and well-being of occupants by establishing benchmarks for optimal indoor air quality. 

  • National Construction Code (NCC): The NCC sets the minimum necessary requirements for the design, construction, and performance of buildings across Australia. This includes HVAC systems. For instance, the NCC specifies certain standards relating to energy efficiency, health and safety concerns, and much more. It’s mandatory for all construction in Australia to adhere to the NCC. 
  • Australian Standards (AS): The AS offers specific guidelines for HVAC systems, including AS 1668.2-2012, which governs the use of ventilation and air conditioning in buildings. These standards ensure the proper functioning, safety, and efficiency of HVAC systems. 


The HVAC system, and specifically the air handling unit (AHU), is a critical component in ensuring comfortable, healthy, and energy-efficient environments, particularly in Australian cities with their unique climates. Proper air handling is paramount to maintaining indoor air quality, building integrity, and occupant health and comfort, while also ensuring compliance with national regulations and standards. 

At Independent Air Conditioning Solutions (IACS), we understand the intricacies of HVAC systems and the importance of proper air handling. With our extensive range of Savier air Handling Systems that have Eurovent certified air, we’re committed to providing solutions that meet your unique needs while aligning with your city’s climate and regulations. 

Whether you’re looking to install a new HVAC system or upgrade your current system, you can trust IACS to deliver excellent service and results. Don’t compromise on the comfort, health, and productivity of your indoor environments.  

Contact us today to learn more about our Savier HVAC solutions and how they can benefit you.