Heating, ventilation, and air conditioning (HVAC) systems play a critical role in maintaining indoor comfort and air quality in buildings. However, they are also significant contributors to energy consumption and greenhouse gas (GHG) emissions. In Australia, for instance, HVAC systems can account for approximately 40% of total energy consumption in commercial buildings and up to 70% of base building energy use. Moreover, according to a report prepared for the Department of Climate Change, the Environment, Energy and Water, Australia’s HVAC system is responsible for 12 percent of total national carbon emissions and uses around a quarter of all electricity used nationally.
These figures highlight the pressing need to improve the efficiency of HVAC systems as part of broader efforts to reduce carbon footprint and operating costs. One effective strategy is the retrofitting of existing systems with Energy Recovery Ventilators (ERVs). This approach not only supports achieving Net-Zero Buildings (NZBs) but also delivers long-term benefits in system performance, indoor air quality, and energy savings.
Understanding HVAC Retrofitting
HVAC retrofitting involves upgrading or modifying existing systems to improve energy efficiency, operational reliability, or capacity without the need for complete replacement. This process is often undertaken to modernize older systems, enhance functionality, and align with current energy efficiency standards and environmental regulations.
The Role of ERVs in Reducing Energy Consumption and Improving Indoor Air Quality
Energy Recovery Ventilators (ERVs) function by capturing heat (and sometimes moisture) from exhausted indoor air and transferring it to incoming fresh air. This energy exchange process reduces the thermal load on HVAC systems by preconditioning outdoor air before it enters the system. Depending on system design and operating conditions, ERVs can recover between 40% to 80% of the energy that would otherwise be lost through ventilation.
This improvement in efficiency directly contributes to lower heating and cooling demands, helping to reduce operational energy costs and associated carbon emissions. In addition to energy savings, ERVs support improved indoor air quality by providing a continuous flow of filtered outdoor air while exhausting stale indoor air. This combination of energy recovery and ventilation makes ERVs a valuable component in optimising building performance and supporting sustainability objectives.
Why Retrofitting ERVs Is a Practical Choice for Existing Buildings
Unlike complete HVAC system replacements—which are costly and disruptive—retrofitting ERVs offers a more cost-effective and strategic solution that delivers measurable benefits:
- Energy Efficiency and Cost Savings: By recovering energy from exhaust air, ERVs reduce the amount of energy required for heating and cooling ventilation air, leading to significant energy savings. This translates to lower utility bills and operational costs over time.
- Enhanced Indoor Air Quality: ERVs facilitate continuous ventilation, removing stale indoor air and replacing it with fresh outdoor air. This process effectively reduces indoor pollutants, contributing to a healthier indoor environment
- Extended Equipment Lifespan: By reducing the workload on HVAC systems, ERVs can extend the lifespan of existing equipment, delaying the need for costly replacements.
- Regulatory Compliance and Sustainability Goals: Integrating ERVs aligns with regulatory standards and sustainability certifications, such as those outlined by ASHRAE and LEED. This not only ensures compliance but also demonstrates a commitment to environmental responsibility.
- Reduced Carbon Emissions: Lower energy use directly translates to lower GHG emissions, helping buildings align with Australia’s decarbonization goals.
Retrofitting ERVs into existing HVAC systems is a strategic move toward energy efficiency and sustainability. It addresses the pressing issue of high energy consumption in the HVAC sector — particularly in Australia, where these systems significantly contribute to greenhouse gas emissions. By reducing energy consumption, improving indoor air quality, and extending HVAC system lifespan, ERVs present a compelling solution for building owners and facility managers seeking to reduce their operational costs and carbon footprints. As the demand for sustainable building practices continues to grow, retrofitting ERVs into existing HVAC systems stands out as a practical, impactful step forward—one that pays off in energy savings, occupant well-being, and climate resilience.
References
www.energy.gov.au/publications/hvac-factsheet-energy-breakdown
www.airah.org.au/Common/Uploaded%20files/Advocacy/2024/AIRAH%20Pre-Budget%20Submission%202024.pdf