Type of works: supply and installation of air-handling units.
Bullet-proof windows, purified air systems and panic rooms are just some of the features of Londons most expensive apartment, at One Hyde Park in London. The HVAC system is equally creative; Fläkt Woods is installing enormous air-handling units, fitted with adiabatic cooling to reject the heat from the 3MW chillers.
Construction work on the scheme is progressing apace, located in the heart of Knightsbridge, this is a housing scheme with a difference. The project features 80 apartments designed by architect Richard Rogers with communal spas, squash courts and a private wine-tasting facility. Its 27,000ft2, £100m penthouse 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.
Because the dry coolers would interfere with the line of site, services engineer Cundall proposed a clever solution, using adiabatic cooling to cool down incoming air before it goes across the heat rejection coil. The airflow is a maximum 180m3/s to make sure that the maximum exhaust temperature was not exceeded.
Cundall is providing building services shell and fit out design, sustainability and IT strategies for the project. 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.
Working out what to do proved a complex design, as John English from Fläkt Woods explains 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.
Measuring 4m wide by 2.3m high, the EUs 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 are effectively supplying free cooling, this means 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, means it is easier to design and install adiabatic humidification systems with confidence, continues John English. It is now possible to convert HVAC and industrial installations with steam humidification systems, to 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 a central controller, which is connected to the building management system via ModBus.
Russian oligarchs, oil barons, Saudi princes and A-list stars are among those said to have already bought units, half of which have already been sold at an average of more than £20m each.
Laing ORourkes design-and-build contract has a value of £490m, its a no-expense-spared job, described as the best project in the world. The scheme features four elongated hexagonal blocks or pavilions linked by stair and lift cores, maximising residents views over Hyde Park.
The building team opted for top-down construction for the four-storey basement. This meant neighbouring buildings were less likely to move than if bottom-up construction were used, and work could start on the superstructure immediately.
Apartments will come with top-of-the-range kitchens and bathrooms, while the bedrooms and living areas will be left for the residents interior design teams to create.
The façade system of residential levels utilises a series of vertical blade-like elements set within an exposed pre-cast concrete frame. The blades provide security, privacy, solar-shading and control views out of the building. They also offer depth, grain and shadow to the façade. The system becomes more transparent to oblique views and predominantly solid when viewed from Hyde Park and Knightsbridge. The blades comprise weathered steel intended to blend with the colouration of building materials in the immediate area.
As the frame moves towards the topping out date in May, the cladding is being installed lower down. This is prefabricated as triple-glazed panels with an interstitial blind. Solid areas have a heavy-duty fibre-reinforced cement board. The prefabricated service modules are beginning to go in and the interior fit-out is just starting. It should take 40 weeks to complete each floor, and once these are finished they will be locked off ready for the residents who move into the development in October 2010.