Intelligent buildings in the Millennium

Air quality, temperature, comfort.

Air quality, temperature and comfort are among the largest management issues facing architects and premises managers in the millennium but places these factors within a broad spectrum of logistical and environmental issues.

Glan Blake Thomas believes that the process of creating a truly ‘intelligent’ building should not necessarily be the installation of an electronic brain or BMS (Building Management System) but rather a co-ordinated methodology which optimises the role of human intelligence at the design stage.

The effective delivery of under-floor conditioned air for temperature and comfort is one of the final ergonomic break-throughs. Adequate fresh air for ventilation, coupled with a high standard of filtration close to the point of discharge remains a vital criterion in the provision of a healthy working environment. Sadly, despite the current quest for 'intelligent building' it is often neglected.

A floor recessed fan terminal unit can be added or removed in less than 10 minutes

Intelligent building must encompass scope for rapid and problem-free change. Important factors are long-term flexibility, ease of control, air quality, maintenance procedures and running costs. A floor recessed fan terminal unit can be added or removed in less than 10 minutes and an under-floor air delivery system will easily and rapidly accommodate the most drastic floor-plan changes - even a switch from cellular to open plan accommodation - without costly structural modifications.

Changes to an under-floor system require few if any costs for rewiring and rebalancing. With traditional displacement air-conditioning, space planning is severely restricted as the siting of partitions and workstations is dictated by the location of air supply units. This can often be to the detriment of intelligent design, with the only alternative being costly remedial work and weeks of inconvenience.

BMS has acquired the status of a demi-god

While the leading-edge BMS (Building Management Systems) integrate effectively with air-conditioning systems, the 'intelligence' on view is often purely electronic with parameters set by the human intelligence responsible for initial commissioning. At the design stage, human intelligence gathers information as to suitable layout and components and then co-ordinates data into an optimum solution. Sadly, the BMS (Building Management System) which has now acquired the status of a demi-god can only optimise what may be faulty input from human intelligence.

The current trend towards distributed data processing means that most office workers have either a personal computer or networked terminal in their work area while many have more than one. Heat loads of 180 watts per sq. metre are now common in many office environments. Computers are often operated close to their upper temperature limitations and excessive temperatures can lead to malfunction and even complete failure. Appreciable temperature differences can now occur only a few yards from a thermostat.

crucial to allow individuals control

This factor combined with individual dress preferences and metabolisms makes it even more crucial to allow individuals control over the temperature in their immediate working environment. It is becoming increasingly important to allow staff to have precise control over the temperature in their immediate work areas. Traditional systems simply strive to produce conditions broadly acceptable to the majority. Even with variable speed settings and efficient links to thermostats it is often found that they suit few if any staff

The most effective and innovative solution lies in the use of raised access flooring to provide under-floor air-conditioning whereby individual electronic controls on each supply unit allow the user to select a wide variety of air temperatures by varying the take-up of cooled air from the floor void.

The flexibility inherent in a modular air-conditioning system can also forestall building obsolescence through its flexibility while also improving general air quality, reducing running costs and rationalising maintenance procedures. This has been a major feature in a recent AET installation at the British Midland reservation centre at East Midlands airport in Castle Donnington near Nottingham. The Hiross air-conditioning has been installed in over 2,500 sq. ms. in 16 zones.

Reconfiguration to suit changing office layouts

Jason Challender of the British Midland Property Department underlines the flexibility of the approach and the intelligence inherent in a modular system: ‘Reconfiguration to suit changing office layouts will be achieved easily since the Hiross floor-recessed air supply units are completely interchangeable with floor panels.’

He continues: The building has been designed on an open-plan basis so that it can accommodate extra staff if required. The flexibility of the Hiross air-conditioning system will be a major benefit as and when usage of the building changes in whole or part. The system also gave our architect considerable freedom with aspect ratios’.

components which are obsolescence free

As more and more new structures incorporate floor voids for IT and telephone cable management, the case for plenum-based air-conditioning becomes overwhelming. It highlights environmental as well as ergonomic issues since truly flexible components which are obsolescence free can adapt to changing layouts and be used to the end of their functional life so conserving the energy used in manufacturing them. Pushed to an extreme, it can be useful to view building components as so many Lego pieces which should be reusable in a multitude of forms.

‘Intelligent’ building can also be regarded as an approach which avoids the hundreds of metres of ductwork which are associated with traditional air-conditioning systems. Such ductwork is extremely difficult to clean. Indeed, the quality of air delivered by a traditional displacement system is often dependent on the cleanliness of the related ductwork, a factor which has appeared regularly after investigations into Sick Building Syndrome. Legislation from Brussels requires ducting to be cleaned every two or three years and this will become a major cost penalty to users both in contract cost for performing the work and in disruption to work patterns.

By contrast, modular under-floor air-conditioning can easily accommodate fresh air intake and accurately control relative humidity within sections of a building. A regular supply of conditioned air is achieved through floor-recessed fan units which draw and deliver air from the floor plenum at a seasonally adjusted temperature with scope for local modification to suit individual or group requirements.

A healthy environment keeps staff concentration levels high

A healthy environment of this kind can assist staff in keeping their concentration levels high, so contributing to productivity. To complement access floor air-conditioning and provide an integrated, intelligent office design, there are a number of compatible accessories such as partitioning, uplighting, cable management, power poles and floor panels of standard and high fire resistant construction. Evenso, truly intelligent building design should not be regarded as stemming from product ranges but rather from a whole methodology of co-ordinating complementary and flexible components.