Entopia Building - Heating / Cooling / Ventilation

The previous ventilation systems consisted of a roof mounted supply ventilation AHU, served by a LTHW frost coil and a post heating coil to temper incoming fresh air. Fresh air is ducted to the core risers and drops vertically to serve each level of the building. On each floor level horizontal ductwork branches from the main vertical riser at high level, then running within ceiling voids and bulkheads to serve supply grilles and diffusers. Extract ductwork (Bellmouth) located around the buildings core, draws extract air back to the riser and back up through building to a roof mounted extract fan which. The WC’s / Toilet Cores are each fitted with a local extract fans located within the ceiling void. Extract ductwork in the toilet cores connects to the fan about the celling voids, exhaust air is connects to the internal/external walls via a louvre.

MEP provision was considered carefully to maximise efficiency and performance. The fabric first approach allowed electrical capacity requirements to remain at pre-refurbishment levels, despite the switch to all electric heating. This avoided the high-cost risk associated with requiring more power capacity from the regional electrical distribution network operator. This was also valuable as it avoided the requirement for a new electrical transformer, for which little space was available on the site. The high performance of the building fabric allows thermal comfort to be maintained with MVHR ventilation and minimal active heating or cooling, including fewer local radiators and fan coil units relative to conventional buildings. Coupled with energy efficient Heating, Ventilation and Air Conditioning (HVAC) specifications, this reduces the amount of energy (and therefore carbon emissions) required to maintain thermal comfort and allows smaller MEP equipment – and less equipment overall (for instance, fewer local radiators and fan coil units) – to be used, this, in turn, reduces the building’s whole life embodied carbon. They designed ventilation ducting to maximise the floor-to-ceiling height in office areas and allow larger ceiling heights than the building afforded prior to refurbishment. Services design included point-of-use tankless water heaters to reduce heat loss from distributing water from a central plant, plus the provision of zip taps to replace kettles at tea points, which were researched to be more efficient based on consideration of likely occupant behaviour.