Ceiling systems from Armstrong – selected for their sustainability credentials – were specified for a new Pre-Operative Assessment Department and Surgical Admissions Suite at Bristol Royal Infirmary.
Armstrong’s CoolZone passive energysaving tiles were installed alongside its Ultima+ range – said to be the world’s first complete ceiling range to win Cradle to Cradle certification – with a Tegular edge detail, on a 24 mm suspension grid, throughout the £2 m replacement Surgical Admissions Suite and PreOperative Assessment Department.
Some 300 m2 of the metal CoolZone tiles, incorporating Phase Change Material (PCM), which absorbs heat during the day, and releases it at night to reduce reliance on air-conditioning, feature, alongside 300 m2 of Ultima+ mineral tiles.
The new building, on the roof of the King Edward Building, is of modular build. It houses 15 consulting rooms, nine changing cubicles, a reception, waiting areas, and associated clinical support services.
The brief from University Hospitals Bristol NHS Foundation Trust to CMS Architects was to provide an enlarged accommodation schedule to facilitate the Trust’s ‘model of care’, which streamlined two services into one department as part of a £143 m investment in the hospital’s redevelopment.
The concept layout was developed with end-users and infection control, hotel services, and facilities management personnel, to consider passive design methods focusing on thermal mass, orientation, and natural lighting and cooling strategies. CMS senior architect, Paul Rogers, said: “The design embraced sustainable thinking from the outset, using prefabrication construction methods, natural ventilation, maximising of daylight with external louvres, and innovative PCM ceiling tiles. The latter absorb daytime solar gains and level any peaks, releasing their stored energy by night-time purge ventilation working with the natural ventilation system. This works particularly well, as the building is only occupied during the day.”
He added: “The project and building design champion sustainable principles. All materials specified were Green Guide A rated as a minimum standard. The PCM tiles enabled us to achieve Part L requirements without the need for cooling.”
CoolZone incorporates BASF Micronal PCM into Armstrong’s plain metal ceiling tiles. This material is embedded in gypsum, and then encased in the metal tile. On heating during the day, and cooling at night, the wax melts and solidifies. Armstrong says internal temperature is thus regulated, ‘reducing and even eliminating the need for air-conditioning’. During initial tests, the CoolZone tiles delayed the onset of air-conditioning by approximately 4-5 hours in an average office. This can reportedly save around 40% of HVAC energy costs, reduce peaks in demand for air-conditioning, and help improve occupants’ thermal comfort.
