Modern Building Services

20 MODERN BUILDING SERVICES OCTOBER 2021 It is too early to know if or how ventilation systems will change in the future to accommodate the risk of infection, however consultants are already considering the impact of retrofit solutions to tie in with occupant comfort as we move into a more sustainable future. Updating study areas to meet demands Leading universities and educational institutions, along with the private sector will have assessed their teaching and workspaces to determine the works that would be needed to not only make it safe for the return of their students but to provide an optimal study & work environment for the future. Given the diverse age of some these estates, which include Grade I and II listed buildings, some of the spaces are served with ventilation equipment that is over 25-30 years old. For these areas to be brought up to recommended levels, Building Managers need to recognise the issues of the existing ventilation which can lead to problems with the build-up of stale air. New advice around Indoor Air Quality (IAQ), and the BESA guidance in place helps Building Managers set up IAQ. Using mechanical ventilation systems and targeted filtration is recognised as the most effective way to reduce the risk of disease transmission. No specific government funding has been allocated to help address this issue, but the Building Managers have acknowledged the importance to refit the spaces with the very latest ventilation & air quality equipment. One thing we are also aware of, is that the constant flow of fresh air is essential where large numbers of students gather for long periods of time to avoid the reduction of alertness and concentration and to reduce the risk of virus transmission. A project recently carried out to a lecture theatre included options to either retrofit the existing ventilation equipment or completely upgrade the system. The controls for the existing ventilation equipment were dated and used a pneumatic air system to control pressure dampers and switches. To overhaul or repair existing ventilation equipment would not be cost effective on the scale of the project, nor would it provide the energy efficiency needed to meet the principles of their sustainability strategy. The installation of newMitsubishi Lossnay heat recovery systems was selected which allows for the continuous influx of fresh air and the exhaust of stale indoor air to ensure that the indoor oxygen levels are maintained for the optimum balance of comfort and safety whilst meeting the required air changes. This heat recovery unit also tempers the supply air using heat transfer from the extracted air without recirculating. The air is heated and cooled using in-line DX Coils piped back to the condensers, this system not only controls the lecture space temperature, but it also helps maintain humidity levels within the recommended parameters. It will extract up to 80% of the heat energy from the outgoing air, transferring it via heat exchanger to heat up the incoming air flow. This will significantly reduce the amount of energy needed to bring the temperature of the lecture theatre up to an optimal level of around 21° and maintain it at this temperature all year round. The energy efficiency and utilisation of heat recovery technology means the DX coils used to temper the supply air are kept down at just 3.12kWmeaning they are the perfect choice for providing a clean and temperate atmosphere for the students within the lecture theatre. With additional units, the capability to give the amount of air changes required for each of the lecture theatre upgrades to meet CIBSE’s guidelines could be achieved. The newly installed units will provide ample fresh air into the lecture space whilst ensuring the correct temperature control for optimum learning. The installation of the equipment will now safely allow socially distanced students in the short term but up to 70 people into the lecture theatre at one time for longer term planning. Summary The importance of Indoor Air Quality isn’t one to shy away from, and studies reveal that the value of having optimal study conditions for students has a significant part to play in the future of educational institutes. In making these adaptations and utilising such energy efficient systems, it allows for extended budgets to be injected directly back into the university’s students’ education while focusing on their safety. FEATURE VERTICAL FOCUS