Glenn Simpson of ENWA explains why water treatment is vital to ensure energy efficiency in HVAC systems – particularly when refurbishing and updating to achieve carbon reduction goals.
University facilities teams have navigated their way through some very choppy waters during the last two years. But even as they manage the long-term impacts of pandemic lockdowns across campuses, they’re returning to deal with the long-term sustainability agenda.
For many years, the UK’s higher education institutions have led the way in sustainable building design and operation. But it’s not an easy task to reduce the energy use and emissions from a university estate. For example, many of them use natural gas for space heating and hot water, and this is responsible for around 60% of carbon emissions in the higher education sector.*
And in 2022, the rising cost of energy is another factor impacting university estates teams. Energy accounts for 18.3% of expenditure in the university sector, amounting to a total (in 2020) of £391 million per year*. Rising energy costs will impact those figures significantly.
With these issues in mind, many universities are looking to improve the efficiency of their existing heating systems or, where possible, adopt low-carbon alternatives such as heat pumps. In addition, the range of buildings in university estates means that facilities teams may oversee properties several hundred years old or built in the last decade, making energy efficient operation more of a challenge.
But whatever the age or type of heating system, good practice in water treatment can provide excellent opportunities for energy efficiency – as well as effective long-term operation.
Strong evidence shows that clean, well-maintained piped services systems are the most effective way to ensure good heat transfer. For example, just 2mm of rust can reduce the heat transfer by 5% across component surfaces. While this may seem insignificant, this performance drop will continue over time and impact energy use in heating systems.
And the problem can be worse in newer systems. That’s because today’s HVAC equipment is designed to be more efficient with smaller plant and thinner, narrower waterways. As a result, any build-up of scaling, corrosion or bacterial contamination can soon take hold.
There is an added problem when new components are retrofitted to existing pipe systems, as might be the case if a university decides to upgrade its older heating system, for example. Poor water quality quickly compromises design efficiencies.
At Enwa, we have worked across hundreds of university projects to help clients optimise their HVAC systems with water treatment that delivers efficient performance – and peace of mind. One example is our EnwaMatic® Side Stream Filtration and Water Treatment system that uses a combination of media layers to filter to <10 microns and regulation pH.
The benefit of our approach is that it is preventative rather than reactive. As a result, water-side components are protected from physical, chemical and biological processes that would otherwise impair their efficiency and reduce their lifetime operation.
For busy university engineers, the EnwaMatic® system has the added benefit of being fully automated and self-regulating – able to send signals through the building management system (BMS) when there is a problem. This capability can help on large estates where a maintenance team may be pressed for time.
As universities look to improve energy efficiency and decarbonise or update heating systems, making the most of those budgets is crucial. Structural integrity and design efficiency must be protected and maintained to maximise the return on investment and minimise the impact on the broader environment.
Making the most of energy-efficient HVAC systems requires greater awareness, and we should assign higher priority to water – the energy carrier itself – and how best to ensure it remains clean throughout the life of the HVAC system.
If you would like to find out more about how Enwa can provide the latest in water treatment services and products, we’ll be at the Association of University Engineers’ 50th Annual Conference from 7th to 9th September. Please come and meet with us.
* Figures from AUDE Estates Management Report Executive Summary 2021