A top hotel in London's West End now boasts a new type of high performance air handling unit.
Klima-Therm has delivered what is believed to be the first UK project of its kind involving the new high efficiency AHU developed by Italian manufacturer Rhoss.
The units 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 takes full account of the requirements of the forthcoming ERP Directive governing sustainable design and energy performance of air movement technology, which is being introduced in 2018.
One of the keys to ADV Next Air’s low energy use and long-term sustainable performance is total thermal decoupling between the internal air handling environment and the external skin, which in such roof-top locations is exposed to wide swings in ambient conditions and direct solar gain.
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 from a system is one of the most important parameters determining the energy efficiency of an AHU. This is because any loss requires a directly proportional input of energy to compensate for the reduction in cooling, heating and/or ventilation that results from leakage.
Moving from an L3 reference leakage value to an L2 value results in annual energy savings of two per cent. Moving from an L2 value to an L1 value results in additional savings of around one per cent. 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 graph (left) shows the relationship between savings attributable to reduced energy use due to the switch to a better leakage class and the purchase price of the AHU in relation to the hours of operation of the system.
The third key design element underpinning performance is tightly managed thermal transmittance. This relates to energy losses out of the system as a result of heat transmission through the materials from which it is made.
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, giving outstanding thermal and acoustic properties, with an overall system transmittence rating of T2.
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.”
He added: “Add to this ease and speed of installation and servicing on the part of the contractor, and we believe ADV Next Air will offers a compelling combination for end users and installers alike, and is set to be a winner.”