Chilled Beams

Keeping the customer satisfied

Building services engineers and architects haven’t always seen eye to eye on the subject of chilled beams, but that is changing says Iskender Gençer of Trox UK.

If there is going to be disagreement in the supply chain, it will often be around the visual impact of air distribution equipment. Building services engineers often encounter technical or practical challenges trying to accommodate the architect’s vision for the space.

Architects often feel that aesthetic impact has to be sacrificed to accommodate the demands of HVAC. But that situation is changing. Over the last few years, the building services engineer has been able to get closer to the architect’s requirements.

So what do architects typically want from chilled beams? In many ways, they want everything the building services engineer wants (energy efficiency, sensible cost etc). But on top of that the architect might also want chilled beams that help them to ‘design the future’, contribute to the visual impact, deliver 21st century air conditioning in old and heritage buildings, suit critical environments, such as operating theatres and laboratories and achieve the architect’s sustainability ambitions.

In the early days it wasn’t always possible to ‘deliver the goods’, but now, chilled beam technology has matured. A variety of different models are available making it possible to meet virtually all technical challenges. There has also been significant capital investment in chilled beam manufacture, making it possible to customise fascia design within sensible budgets and lead times. At the Trox factory in Thetford, for example, we have invested £2.1 million since 2007, installing two fully-automated Trumpf punch presses and an advanced Salvagnini panel bending machine.

So what can the HVAC industry now offer architects that it couldn’t offer before?

Design for the future

For a start we’re now able to help architects by thinking outside the box.

For Trox, linking up with a prominent architect Hadi Teherani, to develop a chilled beam from an architect’s point of view, was an eye-opening experience. The resulting SMART BEAM active chilled beam design was exhibited at ISH 2011 and is now part of the Trox range.

Commenting at the time, Hadi Teherani said: “Our aim was to integrate the air conditioning element into the ceiling design, forming an aesthetic unity with the room without appearing to be an additional item.”

Love it or hate it, it certainly delivers from the engineer’s point of view, providing a volume flow rate from 30 to 120m³ at maximum cooling capacity of 1500 watts and a sound power level clearly below 35dB(A).

Flexibility of design

Not so radical, but still an interesting example of meeting the architect’s brief was a project we carried out recently for the new global headquarters of O’Neill (the original California surf, snow and lifestyle brand).

In creating a raw, industrial look for the space to reflect the brand, the architect wanted to put the inner workings of the building (such as pipework, ducting and wiring) in full view. The bespoke designs created make an edgy design feature of exposed drop rods and connections. The architect’s vision for the space removed any idea of a false ceiling, providing concrete slabs onto which the beams would be mounted. Whilst it would have been quite feasible to conceal the air inlets at each end of the beam, it was decided that using an exposed side entry spigot as a design feature was more in keeping with the architect’s intentions.

Making history

This flexibility of design is also crucial in historic and listed buildings. A recent example is the refurbishment of 157 – 197 Buckingham Palace Road – an imposing art deco building built in 1939 as an air terminal and which now provides the London headquarters of the National Audit Office.

Here the age of the building presented a variety of practical challenges. A number of services needed to be introduced, in a building not originally designed for this purpose, whilst remaining true to the architect’s ambitions for the space. Low floor to ceiling heights of 2.6m meant the design team had to look for an exposed beam solution that would maximise the low height space whilst delivering high levels of cooling and thermal comfort.

For this project, a design committee for the chilled beams including the architect and Trox engineers, collaborated throughout the process. During development, a full laboratory test of the chilled beam, at our site in Thetford, made it possible for the design committee to assess the aesthetic impact of the beam as well as its thermal, audio and lighting performance.

Critical environments

In some projects, architects are driven by the need to deliver specific levels of hygiene and ease of maintenance. Here too, the building services engineer can now deliver an effective solution.

The chilled beams installed in the Royal Alexandra Children’s Hospital in Brighton, for example, are Trox DID 600 Clean Beams. These incorporate features for easier maintenance and cleaning, without allowing room contaminants to migrate from and to the ceiling void or supply ductwork.

The beams are completely demountable, allowing access to each component for quick and easy cleaning by one person. The face of the beam can be hinged down to expose the isolation valve to the coil. The coil can then be disconnected and removed for cleaning. The area behind the coil, within the body of the beam, can also be cleaned, with both operations carried out while the air is running, ie under positive pressure. As chilled beams work on a dry process, there is no moisture on the coil to allow dust and dirt to collect.

As everything is accessible from the face of the beam, there is no need to move ceiling tiles, which might dislodge dirt and risk contamination of clean areas. The beam is also designed with smooth surfaces, avoiding joints or sharp edges in which contaminants could lodge.

An alternative is the hingeable coil version of the Clean Beam which allows the far end of the coil to be disconnected and let down on a guide wire (at an angle of about 45 degrees) for cleaning without stopping operation.

Sustainability

Architects often approach the building services engineer with specific sustainability objectives, such as on-site renewable energy generation. Irrespective of whether this is for a chilled beam or a fan coil based system, this should not be seen as an obstacle. The Trox Design Team and laboratory facilities at Thetford enable us to provide detailed advice on how air distribution parts of the system can integrate effectively (for example, work at higher water temperatures) without compromising energy efficiency.

In conclusion, the gap between the architect and the building services engineer is closing at last. Chilled beam technology needed time to reach maturity, but the capabilities (both technical and aesthetic) are greater than ever before. And that’s good news for both engineers and architects.

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