Discover how Trane Technologies and AL-KO Airtech are leading the way in decarbonising buildings with advanced AHU systems. Learn about sustainable HVAC solutions and strategies to reduce your carbon footprint.

At Trane Technologies, we are committed to decarbonising the built environment by helping our customers to adopt environmentally friendly and energy efficient thermal management solutions. With 40% of greenhouse gas emissions stemming from buildings heating and cooling systems, the approach to reduce this is multifaceted – and ventilation can play a vital role.

In 2023, Trane Technologies acquired AL-KO Airtech, a leading German manufacturer of air ventilation and extraction systems. AL-KO has brought with it over 50 years of experience in designing air handling units (AHUs), built to the highest construction grades and hygiene standard and certified according to Eurovent and EN1886.

Working together through our brands Trane and AL-KO Airtech, our mission is to help facility managers improve the quality and efficiency of thermal management systems in buildings, reducing their impact on the environment while creating healthy spaces for occupants.

The role of AHU in decarbonising buildings
AHUs are integral components of HVAC or thermal systems, responsible for regulating indoor air quality, temperature and humidity through mechanical ventilation. The quality of the conditioned air they deliver to indoor spaces has a significant impact on the health and well-being of building occupants. In fact, ventilation systems play an important role in keeping out particulate matter (e.g. pollution and dust), preventing mold and reducing levels of volatile organic compound gases which can be detrimental to human health.

Ventilation systems and AHU can also be a significant burden on energy bills. The most conventional way of maintaining optimal standards of indoor air quality is by continuously replacing “stale” air with fresh outdoor air. This air needs to be filtered, treated and pre-conditioned through the AHU system to avoid bringing contaminants into the building. Unfortunately, this usually comes with a high energy penalty which inevitably increases the overall carbon footprint of the building.

Decarbonising AHUs involves adopting sustainable practices, technologies, and materials to minimise their environmental impact.

Strategies to decarbonise AHU systems
Let’s explore some actions building managers can take today to make a big difference on their HVAC system’s carbon footprint and therefore their bottom line.

Renewable energy sources. Integrating solar or wind turbines would be a reasonably obvious starting point, reducing dependence on fossil fuels and lowering the overall carbon footprint, given the advancements in energy storage technologies, power can now be reliable and constant.

Decentralisation of HVAC systems can be an additional strategy to improve system level efficiency. Rather than relying on a centralised heating or cooling plant, distributed AHUs placed strategically throughout a building can provide more localised and efficient temperature control. This reduces the need for extensive ductwork and minimises energy losses associated with long-distance distribution.

Improving the energy efficiency of AHUs is a key aspect of decarbonisation. Upgrading existing systems or incorporating new technologies, such as variable frequency drives (VFDs), filters and heat recovery devices can optimise energy consumption. VFDs allow for precise control of motor speeds, adjusting the airflow to meet demand and avoiding unnecessary energy consumption. Heat recovery devices must adhere to minimum efficiency targets set out in the EcoDesign directive.

Recirculation and free cooling where possible will reduce demand on the thermal management system, the use of recirculation or bypass dampers and can dramatically reduce the overall energy consumption. AHU systems can be equipped with cost-effective sensors which monitor air quality parameters and occupancy levels to regulate fresh air ventilation in order to optimize efficiency, without compromising on indoor air quality.

Variable speed fans offer high efficiency and resilience, the use of which help meet specific fan power (SFP) targets set in national building directives. In addition to lower running and maintenance costs, they are also perfectly suited to the integration with building management systems (BMS).

Intelligent control strategy and demand modulation help ensure the ‘system’ is optimised to deliver the best efficiency, even at part load. This can be achieved by continuously monitoring temperature, humidity and air quality at an AHU or BMS level and applying energy-optimising control strategies such us Variable Air Volume (VAV) or Constant Air Volume (CAV).

Minimising installation costs. Using factory fitted packaged controls, mono-block DX systems can be fully wired and pre-piped (interconnecting pipework). The system is delivered on a common base frame with condensers, expansion valves and controls, leaving just ductwork and power supply to be connected on site.

Lifecycle considerations are essential. Proper maintenance procedures of AHUs ensure their longevity and prevent the premature failure of units. Sustainable disposal and recycling practices for end-of-life components contribute to a circular economy, further reducing the environmental impact of HVAC systems.

Traditional HVAC systems are often set-up as siloed heating and cooling plants, resulting in increased system complexity and high energy intensity.

Combining AL-KO Airtech’s AHUs with Trane’s air-sourced heat pumps (ASHPs) provides the optimum combination of efficiency, decarbonisation and electrification:
• The environmental benefits of combining heat pumps with AHUs are dramatic when fossil fuel-based heating systems can be replaced with the latest heat recovery and compressor technology.
• Trane compressors are some of the most efficient on the market and use refrigerants with the lowest global warming potential (GWP) currently available. One such example would be Trane’s new ‘Leaf’ R290 heat pump unit (GWP 0.02) when compared to many DX systems running R-410A (GWP 2088).
• AL-KO Airtech leverages the latest technology in EC fans, filter, and heat recovery, providing AHUs which deliver reliable performance and market-leading performances.

Combining lower (GWP) refrigerants in our heat pumps, pushing the limits of AHU efficiency and using green energy for power, we can help drive HVAC emissions down to almost zero and create a more sustainable future.

Speak to us to see out how we can help to decarbonise your project.

Learn more about AHUs