Thursday, April 11, 2024

Eradicating heating system performance gaps in the public sector estate

Chris Davis, of Hysopt, explains why eradicating heating system performance gaps should be the number one priority for the public sector.

Across the UK and the rest of Europe, energy costs are soaring.  Although there is short-term respite through the Energy Bill Relief Scheme, the cost impacts for public sector organisations exiting their current fixed-term energy supply deals are eye-watering, while there is no certainty of support after April.

At the same time, the public sector has set itself challenging targets to reach net zero – a crucial element of which is decarbonising heat.  The Government’s £2.4bn Public Sector Decarbonisation Scheme barely scratches the surface.

However, the immediate challenge for most right now is mitigating crippling energy cost increases; coupled with almost unprecedented inflationary cost pressures for maintenance and planned capital upgrade programmes.  All of which leaves little in the pot to “save the planet”.


A thread that binds both of these issues when it comes to heating buildings is the Performance Gap. 

In short, this is the difference between how a system actually performs in real life; versues how it should optimally perform – measured across a range of metrics, including energy costs; carbon emissions; occupant comfort.

Eradicating performance-gaps not only enables an immediate (and sizeable) dent in energy costs; but also lays the foundation for cost-effective deployment of low carbon heat, reducing required capex and ongoing opex – as well as maximising carbon saving.  A true win-win.


It’s probably unsurprising that studies of over 400 non-domestic heating installations reveal that 95% performed sub-optimally – they cost more to run and produce higher CO2 emissions than they should.

Shockingly however, these performance gaps mean average energy costs are 32% higher than they otherwise need to be, and carbon emissions 40% higher. Even in new and recently upgraded systems, significant opportunities to optimise performance are being missed.

Further compounding the issue are record increases in gas prices, meaning the underlying cost increase to organisations as a result of performance gaps is running into hundreds of thousands of pounds (even millions) per year in unnecessary and avoidable extra heating costs. 

For example, a 2021 study of a leisure centre’s heating installation showed under-performance caused £84,000 of avoidable annual heating costs.  With current gas and electricity prices, the cost of this performance gap has risen to a crippling £320,000 per year.


With carbon saving and cost pressures mounting, more and more public sector organisations are experiencing how hvac system “digital twins” can help tackle performance gap problems.

Traditional approaches to energy cost saving tend to focus on innovation and solutions at a component level.  But too often there is no predictability of how these will behave in real life as part of a wider, dynamic system. Typically they fail to deliver on expectations.

HVAC digital twins on the other hand are effective at removing performance gaps through their ability to simulate and predict the inter-operable behaviour of the entire system – bringing a measurable, science-based approach to identifying the root causes of under-performance, while also assessing the most cost and carbon effective approaches to resolving them. 


A simple example of this is pump replacement.  Immediate savings of 20-30% can often easily be made by replacing end of life pumps with new, energy efficient models.  However using an HVAC digital twin to properly analyse and optimise the complete system, annual pump energy consumption reduction of 80% or more is frequently identified; while at the same time, required investment costs are often reduced by eliminating pump over-sizing and removing pumps that are no longer required.

Furthermore, the digital twin provides the opportunity to assess what future low carbon upgrades to the system might look like and how these will perform.  This empowers estates and capital projects teams to make more informed, fact-based decisions, while the performance transparency provided by the digital twin is used throughout the design, installation and commissioning stages to ensure the final installation operates as expected “first time right” – firmly closing the “performance gap”.

If you’d like to know more about how hvac digital twins can help tackle your energy and carbon saving issues, watch our recent webinar “Why your heating bills are higher than they should be”

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