HVAC System Digital Twins: A Solution to the Decarbonisation Performance Gap

Chris Davis, VP marketing at HVAC digital twin specialists Hysopt explains how universities and further education colleges can avoid additional risks and costs of decarbonising heat across their estates

For most universities and FE colleges, decarbonising the way campuses and buildings are heated (and cooled) is a significant part of the net-zero challenge. But tackling the issue is not easy.

Fundamentally this means complete transition away from fossil fuels, which is challenging for complex campus sites, often reliant on trusted and well understood gas fired heating; and across a plethora of building types, ages and construction types. Moreover, many have already invested in energy-saving technologies such as Combined Heat and Power (CHP) and distributed heat networks, which makes matters more complicated still.

Public sector heat decarbonisation funding

Universities and FE colleges across the country have already benefited from the government’s £2.4bn Public Sector Decarbonisation Scheme, which provides capital funds for low-carbon heat technologies such as heat pumps, as well as building fabric upgrades and solar photovoltaics.

However, the installation and design of these solutions are complex, often leaving estates and capital projects teams uncertain about expected performance from a carbon-saving, operational cost, and resilience standpoint.

Performance gaps

Building energy performance gaps are a well-known phenomenon and are caused by a range of factors. With heating and cooling representing 70 per cent of building energy consumption and 40-50 per cent of energy cost and CO2 emissions, the impact of correctly performing HVAC installations is critical. Evidence from studies of over 400 installations, including systems in hospitals, universities and other non-residential buildings reveal that 95 per cent performed sub-optimally – meaning they cost more to run and produce higher CO2 emissions than necessary.

Meanwhile, low carbon heat technologies such as heat pumps are not a like for like replacement for gas boilers and even in new and recently upgraded systems, significant opportunities to optimise performance are being missed.

Low carbon heat ready

All too often, low carbon heating solutions fail to perform as expected due to insufficiently well-executed engineering design (too much focus on individual components, without a whole system performance view); poor system commissioning; and failure to ensure existing heating installations are made “low carbon heat ready” first. Adoption of low carbon heat therefore is not simply a question of replacing boilers with heat pumps. It requires a full system, “root and branch” approach in order to ensure that additional capital expense is avoided by eliminating unnecessary plant and equipment over-sizing, and that performance risk is reduced by ensuring all causes of inefficiencies in the existing installation are identified and tackled, before low carbon technologies are applied. This approach will also ensure efficiency of low carbon technologies is maximised by optimising the whole installation for low temperature operation, and that risk of inflated energy costs/carbon emissions is removed as unintended consequences of “value engineering” at the contractor/installation stage. It will also ensure installations are handed over that operate “first time right” through correct commissioning; Hysopt has produced a useful e-book which covers this in more detail.

How do HVAC system digital twins help avoid these risks and costs?

An HVAC system digital twin is a virtual replica of the heating and cooling system installation that allows the planned design to be optimised before building it in real life; while also providing the necessary transparency and continuity across all project stages to ensure the optimised design intent is delivered in the final physical installation. This technology is valuable for evaluating the potential performance of alternative options in the engineering stages against project KPIs such as carbon and energy costs, empowering estates and capital projects teams to make more informed, fact-based decisions during the early stages of a project and engage with their supply chain in an open and transparent way. Moreover, a digital twin acts as a single point of truth for system performance at all stages of the project design, engineering, installation, commissioning, and hand-over processes, ensuring the risk of energy cost or carbon emission performance gaps is avoided and low-carbon heating installations operate and perform as expected “first time right”. Project teams have also found this alternative approach can reduce overall project viability risk by driving down capital expenditure costs and removal of assumptions and margins for error, which traditionally tend to cause over-inflation of build risk and “optimism bias” in the calculation of capital project budgets related to the specification and procurement of hvac plant and equipment.

Beware the risk of status-quo

Given the importance of decarbonising heat in achieving the education sectors net zero ambitions and complexity, costs and risks involved, more and more higher and further education establishments are adopting an approach using HVAC system digital twins to help tackle these issues within their low-carbon heat projects; minimise performance gaps; and ensure that lowcarbon heating solutions meet the expected performance results from a carbon-saving, operational cost, and resilience standpoint. The value offered by adopting an approach incorporating hvac digital twins means universities and colleges should no longer be asking “should we use a digital twin?”, but instead “how can we expect this project be delivered on budget and perform first-timeright as expected without using one”? L