QCDA, Coventry

As more building developers look to create sustainable, low-energy buildings passive chilled beams are becoming an increasingly popular choice. Not only do they offer an energy efficient alternative to other air conditioning systems, they can also be designed to incorporate other aspects of building services including lighting.

Key features

Sector

Commercial

Client

John Sisk

Architect

BBLB

Sub-contractor

SAS International

Completion year

2009

System type

Integrated Service Modules | ISM

Area M2

1,375 linear metres

Region

United Kingdom

Product Groups

A recent example of the use of passive chilled beams as part of an overall strategy to create a sustainable office building is at the new Earlsdon Park project in Coventry. Developers MCD Developments wanted to create a mixed use development of high quality office accommodation, residential apartments, restaurants and bars. The site also incorporates leading edge eco-friendly building technology to reduce the carbon footprint of the whole development. 

One of the most significant buildings on the site is an office which has been occupied by the Government’s Qualifications and Curriculum Development Agency (QCDA). This ten storey office building has achieved a BREEAM Excellent rating, and uses many sustainable design techniques as well as chilled beams. This was particularly important for QCDA, as sustainability was an important condition of the Agency taking space in Earlsdon Park.

Jennifer Price, development executive at MCD Developments, says: “This building has been designed so that its orientation, office plan depth and the central atrium all work together to provide good levels of natural light and ventilation.” The building has a number of features that are not usually associated with a commercial office building, including the use of natural ventilation and a reinforced concrete frame. 

“Gaining a BREEAM Excellent rating is still very difficult to achieve,” says Price. “You have to significantly exceed the current building regulations and incorporate the latest environmental and energy saving solutions, as well as looking closely at the constructional methodology and the expected use patterns of the building.” 

Created in partnership with local architects BBLB, the building includes one of the first speculative, commercial-scale ground source heat pumps in the UK. This heat pump system is linked to 1,375 linear metres of SAS International Integrated Service Modules (ISMs) with passive chilled beams. ISMs can integrate either passive or active chilled beams with building services elements, such as luminaires and other M&E components, into a single off-site manufactured module. 

The heat pump supplies 47% of the building’s total project energy demand. There are approximately twenty 200m deep bore-holes, and these simultaneously provide chilled water to the passive chilled beams. 

The specialist heating division of SAS International, HCP, supplied Trench heating which has been applied to areas near the perimeter of the office space. Trench Heating is ideal for combating cold down draughts and condensation, characteristics are often associated with full and half height glazing and provide an effective heat source where wall space is limited. In the case of QCDA in winter the hot air that rises up through the atrium area and is passed through a heat exchanger which recovers the energy for fresh air ventilation.

As with all sustainable buildings, all the elements of the design must work together, including building fabric as well as building services. A key element in enabling the system to operate effectively is the use of exposed concrete soffits and a night-time ventilation strategy. The large thermal mass of the concrete building creates a dampening effect which stops the building overheating. This reduces mechanical cooling requirements. The concrete mass absorbs heat during the day, and this is released during the night as windows open automatically to move warm air out of the building. By reducing the work of the passive chilled beam system, energy use is cut even further. Price comments: “This system provides an extremely energy efficient method of cooling, which is always the challenge in
modern offices.”

Systems used