Smart Swede

Swedish culture is so well-defined it is almost a parody of itself. From Volvo to Bergman and saunas to smörgåsbord, it has survived relatively unscathed during two world wars and membership of the European Union. Even the new road-bridge to Denmark hasn’t fazed the country’s modest and still largely indigenous population, despite needing to dig up half of Malmö to do it.

Building regulations? Nei, inte alls. Swedish buildings are so efficient and the construction industry so disciplined that much energy legislation has become redundant. In any case the climate doesn’t allow architectural stupidity, so there are few fully-glazed buildings. The downside is an absence of frivolity or technical innovation – the differences between a house built today and one constructed 50 years ago are imperceptible.

Commercial buildings are another matter. Sweden is as prey to the demands of the high- tech office market as any other country in western Europe. This translates to high specification, good net lettable area, and flexible designs which can cater for future change of use.

This building, the US$15 million Gåddan 8, is a case in point. More importantly, it also demonstrates how sustainable design can coexist with the demands of the office market. The solutions lie not just in traditional Swedish passive solar engineering (of which this building has its fair share) but also in the prudent use of smart technology that allows the base services to be easily reconfigured for different occupiers.

Gåddan 8 was constructed just over a year ago by the property owner Diligentia Syd AB as the first of ten buildings intended for the new Malmö University. The University centres on sustainable engineering and business management training, along with health sciences, odontology and arts courses.

The University was insistent that this modus operandi should be reflected in the building’s architecture and servicing. It wanted “a house, reliant on proper environmental considerations, removed from rhetoric and environmental opportunism...which can be an example of the environmental training it envisages harbouring”.

Gåddan 8’s 12 000 m² floor area is divided between two virtually identical but structurally separate buildings connected by a glazed atrium. This atrium essentially doubles as a covered street and an exhaust route for the mechanical ventilation.

The two wings are traditional heavyweight concrete structures, with an appropriately balanced glazing-to-envelope ratio. Each block has five occupied floors with plant located in roof-voids and basement plantrooms.

Diligentia Syd AB designed Gåddan 8 as offices, hence the existence of the basement car park. Indeed, telecommunications firm Telia has taken tenancy of the second floor, largely because the fledgling University didn’t need all the space. With the exception of a cafeteria and lecture theatres on the ground floor, the remaining levels are partitioned into classrooms and workroom spaces of varying sizes.

Base building services

Cooling and heating pipes embedded in the floors enable the building to act as an accumulator. This system is also arranged so that waste heat from one building can be pumped into the other.

The local heating company could not convince the client that the district heating was run in the most environmentally-friendly way. Hence, heating is via two Viessmann gas-fired boilers (575 kW and 675 kW) – a rare option outside major Swedish cities.

The domestic hot water is preheated by solar collectors, while heat recovered from the ventilation extract preheats the incoming supply air.

Mechanical cooling uses a York Millennium chiller running on R407c. The waste heat is rejected by a heat exchange circuit running off the local canal. This allows for a free cooling cycle when temperatures permit.

The canal is also intended to provide water for toilet flushing, but this will only happen once the toilet bowls are out of warranty, such was the resistance by the manufacturer to the idea. In any case the canal is proving a mixed blessing, with the inlet grille regularly getting clogged with grass, plastics bags and the odd dead duck. In the absence of a reversible system, the building managers either clear the obstruction manually or wait a while before running the pumps again.

Ventilation is handled by conventional air handling units with the aforementioned heat recovery. Air is supplied down exposed ducts which are suspended off the atrium elevations. These ducts branch off into each floor.

Conditioned air is injected at low velocity into the occupied zone via very simple spiral-bound ducts punctured with small holes. The effect is not dissimilar to inflated fabric socks. It demonstrably makes for draught free ventilation, albeit executed with rather clinical simplicity. Extract is back out into the atrium.

The exposed, coffered concrete slabs provide the thermal coupling, while wall-mounted power and datacoms trunking does away with the need for a raised floor.

Electric lighting uses dimmable fluorescent lamps throughout. These are mostly operated on presence detection, even in the corridors (which seems a bit overzealous, but the building is open 24 h/day, seven days a week). In the rooms, linear fluorescent lamps in batten fittings are slung between the downstand beams, which are on 1·5 m modules.

Controls integration

It is on the controls side, though, where Swedish simplicity gives way to North American controls sophistication. For Gåddan 8 represents one of the first major installations in Sweden of the Lonworks open controls system.

The Lon protocol, marketed with such enthusiasm by Echelon, is a software product which enables building services systems from different manufacturers to exchange functional data. Such integration is made possible by product suppliers embedding their components with Lon-based software rather than a proprietary language.

The building’s developers were very keen for its services to be adaptable for future change of use. What Lonworks allows (as indeed will any public domain open communications protocol like BACnet or EIBus) is easy reprogramming of hvac and lighting at the level of the individual component. This means that rather than having to install new controllers or indulge in expensive rewiring when changes occur, existing systems can be simply reprogrammed and/or regrouped. It is also easy to add more controllers on the twisted-pair data loop.

Swedish-based controls firm TAC (formerly Tour & Andersson) designed and supplied a TAC Vista front-end building management system. It also supplied the networked Xenta controllers which monitor and run all hvac functions, the lighting in the classrooms, access, security and fire detection systems, and even the building’s 30-odd wall clocks.

The network is divided between a high-speed 1·25 Mb Lonworks backbone and several 78 kb networks for on-floor communication.

Does the system work?

Proof of the control system’s virtues is demonstrated by the ease with which the tenanted second floor has been hived off from the rest of the building. And when Telia relinquishes the lease, it should require very little effort to bring the floor back into the building’s main control loop.

Second, the building managers are able to control not just the provision of ventilation and lighting on an individual room basis, but also access to all rooms via a swipe card system. This offers low-level security, but more importantly, integrated control over the environmental services based on local occupancy.

All students are given a magnetic card, which is used in a swipe controller to open classroom doors. Doing so activates the mechanical ventilation, the cooling and the electric lighting.

Ventilation rates rise from a background level on infra-red presence detection as soon as someone enters a room. Further increases are controlled by air quality sensors.

Lighting is activated from push buttons and deactivated by the presence detectors. (Note that the latter are able to perform this dual role by virtue of the open communication between the ventilation and lighting circuits).

The swipe card system also enables the building’s managers to program a security procedure on whatever criteria they wish – timing, location, etc – on a room by room basis. Again, by virtue of the open communication protocol, alarms can be tripped by the presence detectors. The magnetic sensors on the doors or acoustic detectors are mounted within the manual door handles, which are normally encased in break-glass domes. These alarms can be relayed to the security company.

Indeed, with motion sensors covering almost all the occupiable spaces, combined with the access-point readers counting people in and out of the building, it is possible to use a function called ‘empty house’. This is a software-based function that can be used to turn the burglar alarm on and off in different areas of the building. However, Gåddan 8 did not benefit from this due to lack of design time.

The almost bewildering array of options which comes from these integrated functions gives the building managers an awesome amount of power. The TAC Vista front-end acts as the monitoring hub for the 300 Xenta controllers and over 800 Lonworks ‘nodes’ dotted around the building, making it is a crucial piece of kit.

Martin Näslund of the project’s consulting engineer Sycon warns that extracting such functionality depends on the system being considered very early in a project. “You need to think quite differently to traditional systems,” said Näslund. “All the functions and purposes of an open databus must be considered early in the life of a project and checked out with the building users. It is also important to choose a system integrator to avoid anarchy among the consultants,” he added.

Despite the building’s low energy credentials, the client is not monitoring and targeting the building’s energy consumption, largely because it didn’t buy the relevant bit of software. This is very disappointing. But in any case there were no formal design energy targets – strange given the client’s high ideals. Perhaps Swedes believe all their buildings are inherently good energy performers. And perhaps they are.

Still, on the basis that what you don’t measure you can’t manage, the jury is still out as to whether Gåddan 8’s aspirations as an energy efficient building are truly being met. Bogart may be meeting Bergman, but the fundamental things apply.