If we are to reach net zero, then we need efficient, sustainable, and cost-effective HVAC systems, says Ralph Davies
According to the UK Green Building Council, the UK’s existing non-domestic building stock is currently responsible for almost a quarter of the operational carbon emissions from buildings. When you consider that approximately 80% of the buildings in use today will still be in use by 2050, our traditional reactive maintenance approach to servicing is going to prove inadequate.
We need to support building owners and operators with a more holistic approach to get the very best out of their HVAC systems. The building of the future isn’t going to be defined by the features and technologies that go into them, but by what building owners, operators and occupants can get out of them.
Having a broader perspective of a building’s heating, cooling and ventilation systems ensures that every phase of its lifecycle – from design and installation through to operation, predictive maintenance and eventually, replacement.
With a building’s assets managed by software and cloud-based digital platforms, advanced technologies and algorithms can be used to enable real-time, intelligent outcome-based results. This will maximise the efficiency of a system and minimise the environmental impact.
Modernisation for the win
Existing buildings are a key focus because it is estimated that 87% of the improved performance from the UK property sector that will be required to stay within climate targets will need to come from the current stock.
One of the ways to improve performance and to reduce carbon emissions is to adopt a ‘Modernisation Approach’ and to improve the asset life cycle management of systems, already installed and currently in operation, such as heat pumps and chillers.
The key to any successful service modernisation project is collaborating with the customer through a number of key stages:
Carrier’s engineers can conduct energy audits which offer a deep dive into original system design, adjustments and changes over time; and current and future load profiles; and help to establish the all-important energy usage baseline. This stage is very data-driven and helps to determine the summer cooling load profile and winter heating load profile, which are important for decarbonisation.
Engineers then present a turnkey offering, detailing the return on investment, CO2 reductions and operational savings.
Once the details are agreed, new equipment can be selected, installed and commissioned. All of Carrier’s latest chillers, rooftop units, and heat pumps offer digital connectivity, which allows for ongoing diagnostics and improved performance through Abound HVAC Performance service platforms.
Putting this into practice, one recent project involved an overhaul of an existing HVAC system, which included the installation of multiple high-efficiency water-source heat pumps and chillers. The project realised projected energy savings of 0.67 million kWh per year and CO2 savings of 11,100 kg annually.
Upgrading the drives
Today, more than 750,000 medium-to-large-scale existing HVAC units require technology upgrades to meet efficiency and decarbonisation targets.
One of the most effective ways to optimise energy in HVAC systems is to upgrade old equipment with Variable Frequency Drives (VFDs) and to update their controls. VFDs regulate the speed of motors to match the load requirements, significantly reducing energy consumption. Upgrading the control systems to the latest generation technology further enhances this effect by allowing the condensation setpoint to be lowered, optimising power usage.
Carrier offers a phased approach to upgrading fan motors with VFDs, which sees all machine fan motors replaced, then the VFDs installed, and finally, the control system and displays are fully replaced.
During another recent project, Carrier fitted a VFD fan and upgraded controls on an AquaForce 30XA (400 kW) chiller. The 30XA provided cooling for a large building, operating for 6,777 hours a year, with a total annual consumption of 831,732 kWh. As the customer was paying 32p per kWh for electricity, this resulted in a bill of over £250,000 per year.
Thanks to a significant investment in equipment upgrades, the customer was able to reduce the energy consumption by over 26,000 kWh a year. Carbon emissions fell in turn by 2,092 kg CO2e per year, and the system’s Energy Efficiency Ratio (EER) increased from 3.1 to 3.18. This meant that after just two years, the customer was able to see a return on its investment.
Digitalisation brings efficiencies
We’re living in a digitally connected world, and in the HVAC sector, technology now makes it possible to build a real-time picture of how heating and cooling systems are running and, therefore, to analyse where and when issues could occur. Our Abound platform uses AI to extract insights from the operating data and can thus pre-empt issues before they escalate into costly breakdowns.
By integrating advanced digital tools, upgrading critical components like VFDs, and committing to a comprehensive modernisation strategy, we believe we can help building owners and operators to reduce the risk of unexpected downtime and to maximise equipment lifespan and performance.
Ultimately by fully embracing lifecycle asset management, building owners and operators can achieve significant energy savings; reduce CO2 emissions; and meet the decarbonisation goals they are striving for.
