The 5-star Radisson Blu Edwardian Hampshire Hotel is situated on Leicester Square in London’s lively West End

UK: The 5-star Radisson Blu Edwardian Hampshire Hotel in the heart of London’s theatre land recently checked-in a new type of high performance, high efficiency air handling unit.

The hotel is now home to two ADV Next Air units, developed by Italian manufacturer Rhoss and meeting forthcoming ERP energy efficiency directives thanks to their exceptional air tightness and avoidance of thermal bridging.

The air handling units were delivered by Klima-Therm in what is believed to be the first UK project of its kind involving these air handlers. They were shipped in a single module from Italy direct to central London for lifting by crane onto the hotel’s roof, and installation by contractor Koolmar Ltd.

The system is said to take full account of the requirements of the forthcoming ERP Directive governing sustainable design and energy performance of air movement technology, which is being introduced next year.

One of the keys to ADV Next Air’s low energy use and long-term sustainable performance is said to be its total thermal decoupling between the internal air handling environment and the external skin. This is an important consideration when exposed to the wide swings in ambient conditions and direct solar gain encountered in such roof-top locations.

Advanced materials and a new design which avoids thermal bridging means the Rhoss system achieves the highest attainable reference standard – thermal bridging Class TB1.

Another key to its energy performance is exceptional air tightness, ensured by the close-tolerance fit of individual panels, sealed with special high compression gaskets into their seatings within AHU body. This enables it to achieve the highest attainable air tightness rating, Class L1.

Air leakage is one of the most important parameters determining the energy efficiency of an AHU. Moving from an L3 reference leakage value to an L2 value results in annual energy savings of 2%. Moving from an L2 value to an L1 value results in additional savings of around 1%. With potential energy costs running into hundreds of thousands of pounds a year, this results in a significant saving in cost and carbon over the plant’s life-time.

The third key design element underpinning performance is the low thermal transmittance of T2. To achieve this the ADV Next Air units are constructed from 50mm thick sandwich panels, with inner and outer surfaces made of heat-galvanised sheet-steel coated with polyurethane, and insulation made from self-extinguishing injected PUR at a density of 47kg/m³.

Indoor air quality and occupant well-being is ensured by the use of high-tightness air filters coupled with a biocide filtration system developed by specialist Labiotest working in collaboration with Rhoss.

The onboard intelligent control system monitors performance and continuously optimises energy savings, as well as ensuring rapid connectivity, commissioning and ease of service and maintenance. It can be fully integrated with all the main building management and supervisory systems, enabling a total energy management approach to a building or estate. 

Mircea Catana, Klima-Therm’s technical engineer who headed up the project, said: “Air handling unit technology had advanced little in the past few decades. However, with its combination of innovative design features, advanced materials and intelligent control, ADV Next Air represents the next generation of AHUs. It delivers full spectrum, high performance cooling, heating and ventilation, with outstanding energy savings and occupant comfort.”