Heating, Ventilation & Air Quality Ventilation compliance made clear Roy Jones, Technical Director at Gilberts Blackpool endeavours to clarify and simplify the complex issue.


Thermal comfort and overheating: Buildings must minimise overheating in accordance with the DfE’s Overheating Risk Assessment methodology, while avoiding discomfort from cold draughts.


Acoustic comfort: Spaces must meet BB93 requirements for ambient noise, reverberation and sound insulation, with particular consideration for pupils with hearing or speech needs.


T


he latest Department for Education [DfE] standards have made designing and delivering ventilation in educational establishments increasingly complex. However, with the right advice and up-to-date product technical information, compliance need not be daunting.


The DfE Technical Manual – Employer’s Requirements, issued as part of Construction Framework 2025 [CF25], sets detailed expectations for indoor environmental quality, operational energy, carbon performance and whole-life sustainability. Designers, contractors and consultants must demonstrate that ventilation strategies support these outcomes while remaining practical to install, operate and maintain.


Key DfE objectives include:


Healthy and productive spaces: Learning environments should provide good indoor air quality and comfortable thermal, acoustic and visual conditions, with ventilation integrated alongside daylight, heating and cooling.


Reducing carbon emissions: New schools and colleges must minimise operational energy demand and whole-life carbon. Designers must also assess embodied carbon and replacement cycles over a 60-year reference period.


Climate-resilient design: Buildings must remain comfortable under changing climate conditions, including hotter summers and extreme weather. CIBSE DSY1 50th percentile low-emission 2080 weather files should be used.


Nature connectedness: Designs should incorporate nature-based solutions, including passive ventilation and biodiversity measures.


Efficient resource management: Systems should operate reliably for decades, with minimal intervention and straightforward servicing.


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Operational energy and carbon: Maximum energy use intensity [EUI] targets are 52 kWh/ m² for primary schools, 60 for secondary schools, 70 for colleges, and 52 for special schools, colleges and alternative provision [AP]. At least 60% of annual energy demand should be met through on-site renewable generation, with a minimum yield of 45 kWh/ m² of building footprint. Energy use must be dynamically modelled using CIBSE TM54 and 2020 Test Reference Year weather files, including anticipated out-of-hours community use.


The guidelines also set specific requirements for teaching and communal spaces. Ventilation should be predominantly passive wherever possible, using cross-ventilation in teaching spaces, seminar rooms, staff rooms and social areas. Where mechanical ventilation is required, supply and extract units should incorporate heat recovery unless unsuitable. Recirculation is not permitted when serving multiple spaces.


It is not simply airflow that needs to be considered. CO2


levels must also be controlled.


General teaching spaces should achieve a daily average concentration below 1,000 ppm, with 1,500 ppm permitted for no more than 20 consecutive minutes.


The whole system needs to be effectively managed, with the building management system [BMS] automatically controlling and monitoring ventilation, heating and cooling alongside air quality and energy consumption. The BMS and associated controls must be reliable, adaptable and straightforward for school staff to operate following handover.


With the DfE Technical Manual updated in January 2026, it is essential that design teams work from the latest guidance rather than relying on previous versions.


Despite the many required design conditions, compliance can be achieved more simply than may initially appear. It is not simply about the choice of ventilation system, but how that system contributes to a whole-building approach.


Hybrid natural ventilation with heat recovery, such as Gilberts’ MFS-HR, is increasingly suited to educational environments. The façade-


Autumn 2026 issue 4185


integrated units combine passive ventilation, low-energy mechanical support and heat recovery within a single product.


Strategically integrated into the façade, the units prioritise natural ventilation through passive stack and cross-ventilation, maintaining a connection between the building and its outdoor environment. Mechanical fan support operates only when necessary to maintain preset internal temperatures. An integrated heat exchanger transfers warmth from extracted air to incoming fresh air, reducing the energy required to maintain comfortable indoor conditions.


The latest test figures show that MFS-HR achieves up to 75% heat recovery, described by Gilberts as best in class for a hybrid product. It is also CE marked to the relevant Eco-Design Regulations ventilation requirements.


In hot weather, MFS-HR’s cool-recovery function helps limit overheating in accordance with BB101 criteria, while its night-purge facility supports climate-resilient design.


The unit also contributes to whole-life performance. Manufactured in the UK, it can reduce embodied carbon associated with transportation. It is thermally broken and virtually airtight, with air leakage of just 3m³/ hr/m², while achieving a U-value of less than 1 W/m²°C.


The low-energy fan can also be powered using solar-generated electricity where incorporated into the school’s building services, potentially helping to further reduce operational carbon.


Alongside MFS-HR, Gilberts has developed a dedicated chimney penthouse solution for vertical exhaust ventilation across multiple floors, without relying on shared corridors or central ductwork.


This chimney-based approach allows extract air from each teaching space to rise through a continuous, contained shaft before being discharged at roof level, mirroring the natural stack effect of traditional chimneys. The roof outlet provides an independent route for warm, stale0 or pollutant-laden air to escape while maintaining air quality within individual teaching spaces.


By combining façade-based hybrid ventilation with vertical exhaust infrastructure, Gilberts can support DfE ventilation strategies from individual classrooms to whole-building systems. This integrated approach helps design teams address air quality, overheating, acoustic performance and passive ventilation principles, while simplifying coordination between architecture, structure and building services.


gilbertsblackpool.com


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