Fläkt Woods recently installed enormous air handling units, fitted with adiabatic cooling to reject the heat from the 3MW chillers at London’s most prestigious block of apartments.

Located in the heart of Knightsbridge, this is a housing scheme with a difference. The project features 80 apartments designed by architect Richard Rogers, and a 27,000ft2, £100m penthouse which will become the most expensive flat in the world, upon completion in 2010.

Originally, the design team proposed roof mounted dry coolers, however, as one of the development aims was to compliment the existing streetscape of Knightsbridge, creating a scheme that offers daylight and generous views, this idea was scrapped.

With the Mandarin Oriental hotel next door and a residential block the other side, releasing air at the right temperature into the atmosphere was critical. Services engineer Cundall proposed a clever solution, using adiabatic cooling to cool down incoming air before it goes across the heat rejection coil.

“Space was extremely restricted, the idea of adiabatic cooling within the psychometrics of our EU air handling system was a bright idea, and fortunately we were able to provide this from our existing EU range,” explained John English from Fläkt Woods.

Measuring 4m wide by 2.3m high, the EU’s are based on the 84 model, but have a special cross section to provide the lower height necessary. The eight units fit together two on top of each other, with a clearance of just 100mm to the top of the stack.

The EU air handling units effectively supply free cooling, meaning that the adiabatic system will be called on only when the cooling source of outdoor air is fully exploited. So in summer months, the adiabatic cooling effect is capable of removing some 8ºC from the ambient air. 

The adiabatic humidification process relies on the heat in the air to provide the energy for vaporization and absorption. In HVAC applications, the moisture is absorbed into the moving air stream. The absorption efficiency is dependent on the humidification chamber configuration, air temperature, RH and velocity of the air. The heat used to absorb the moisture cools the air.

“Our experience gained from HVAC installations using adiabatic technology shows that it is easier to design and install adiabatic humidification systems with confidence”, said John English. It is now possible to convert HVAC and industrial installations with steam humidification systems, into adiabatic systems with large reductions in energy and maintenance costs.

Other EU supply and exhaust air units are being supplied, to supply air into the building, and are linked to central controller, which is connected to the building management system via ModBus.

Source: Fläkt Woods

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