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HVAC for schools


Water quality – a vital component for every HVAC system


When it comes to specifying a new HVAC system for schools, or continuing to maintaining an existing but ageing one, many factors need to be taken into consideration. James Hurtley, area sales manager at Spirotech, outlines some of the key elements that need to be factored in to meet both current and potential future demands


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chool budgets are coming under ever increasing pressure, with heating the buildings being one of the biggest


expenditures that bursars need to meet second only to salaries. For those schools with ageing HVAC systems, bursars are having to carefully consider the overall financial picture and take into account lifetime operating costs – do they continue to maintain and replace items as they go along, or do they bite the bullet and install a completely new system, starting with the boiler room? Children need to be taught within comfortable


classroom conditions but there is no minimum temperature guideline for any part of a school under the School Premises (England) Regulations introduced in 2012. However, the National Education Union (NEU) maintains that the minimum temperature in a classroom should be 18 degrees centigrade. Having an efficient, reliant heating system is


more important than ever with escalating energy prices showing no signs of abating in the short- term. Should the decision be taken to install a new HVAC system, it is vital that a comprehensive audit is undertaken at the planning and design stages to fully understand what the new system will need to deliver operationally. Only after undertaking this audit will it be possible to specify the right


equipment to do the job, and have a thorough understanding of the technology and its application. It’s not just a question of delivering services to the


existing school buildings, it’s important to consider likely future needs and build in some additional capacity. For example, many education authorities across


the country are coming under pressure to provide additional pupil places, potentially requiring a need for additional classroom blocks and possibly additional washroom facilities and sports halls to be built; all of which would require heating and water services. When setting up any system, key factors that need to be taken into account include that of pressurisation, correctly sized expansion


tanks and hydronic balancing. If these are miscalculated or fudged, then malfunctions become pre-programmed, inefficiency is in-built and breakdowns are almost inevitable, even if not immediately apparent. The removal of dirt and air separators is far too


common from heating systems, despite the fact that good quality products will safeguard against the costly breakdown of boilers and other system components by preventing the build-up of dirt and air. Getting the conditioning of the water right within a


system will play a central role in ensuring efficient, trouble-free operation and a long system life. Get it wrong and the consequences can be anything from under performance to system failure. Putting in a completely new system may need to be undertaken in stages, with the work almost certainly undertaken during the long summer vacation break. The size of the school, the spread of the buildings and output needed to be delivered will impact on which HVAC system is installed within the available budget. At the heart of any system is the boiler and there may be more than one installed across the site. A school will need a pressurised unit with an


integrated degasser or series of degassers. Vacuum degassers work by reducing the pressure in the vacuum vessel that sits within the unit. This liberates dissolved gases from the system liquid in the vessel and the accumulated gas can then be expelled. Once commissioning is complete, control and monitoring can be achieved using a touch screen on the unit, through a building management system or via the internet on a PC, tablet or smartphone. Functions such as on/off, error and alarm reset, and degassing, refill and boiler interlock on/off can be controlled remotely, while parameters can be set for such things as system pressure, refill pressure and boiler interlock. The most modern feature a comprehensive unit status and event history, providing real-time data and enabling performance to be tracked in detail over time. This higher level of information gathering will, among other things, enable predictive maintenance and servicing, leading to increased reliability and performance, and ultimately cost savings. Specifying the right system is key to providing an efficient HVAC system, but it is important that contractors further down the line don’t start making decisions based on cost-savings as these may ultimately impact on performance.


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