Fraunhofer Institute for Building Physics IBP
Office workers account for some 40 percent of Germany’s workforce. Their places of work are many and varied: across the country, in companies large and small, office workers sit and earn their living, some in modern blocks, others in dated offices, some sitting together in an open-plan environment, and others in separate offices. For some the focus is creative, for others operational, while many are expected to complete various tasks in the course of their working day. Ultimately, every worker should be able to do their job efficiently and in a way that delivers results, regardless of their role. Research has long shown that the way rooms and workspaces are organized has a significant impact on health, wellbeing and performance – and yet many of Germany’s 17 million or so office workplaces are ill-equipped for the demands of the modern workplace, despite adhering to current standards. In many cases, the result is sensory overload and a lack of privacy, leading to distraction and stress. This comes back to bite employers in the form of general dissatisfaction, reduced performance, increased absence and higher sickness rates among staff. In the worst case, it can even be responsible for increased employee turnover.
"People inside" (“Menschen in Räumen”) is a current hot topic of research for both Fraunhofer IBP and the associated graduate program of the same name at the University of Stuttgart. Here, engineers, psychologists and economists are investigating the various parameters that deliver the maximum possible sense of wellbeing. Their research includes interdisciplinary building and technology solutions, and looks at buildings’ operating efficiency as well as how indoor spaces affect people and their performance. For instance, studies have shown that bright environments with light levels of 1500 lux support logical thinking, while lower lighting conditions of barely 150 lux help with creative tasks.
In order to establish an interdisciplinary R&D platform specifically for the office sector, Fraunhofer IBP launched the Fraunhofer Office Initiative, and has also brought on board businesses, office planners and operators, as well as institutions and authorities. "Accounting for both new builds and renovation projects, Germany’s office space is growing at a rate of almost three million square meters a year. These buildings are increasingly economical, energy-efficient, automated and officially approved. And yet practice shows us that the work environment employees see, hear and perceive is clashing with their needs and expectations. That’s what we want to address with this office initiative," explains institute director Prof. Philip Leistner. Some 80 percent of the costs associated with office buildings go on employees, and just 20 percent on technology, operating costs, the building and furnishings – testament to the importance of people, who now spend 90 percent of their time in enclosed spaces.
The trend towards open-plan offices isn’t purely to do with efficient use of space. Architects and employers hope that it will encourage more communication among employees. However, it is now clear that the users of these spaces often perceive their open-plan character as a barrier to concentration and an invasion of their privacy. This can mean increased stress for employees, who must expend extra energy to compensate for external disruptions.
"In order to provide office users with the best possible working environment while keeping a close eye on operating efficiency, we are using the office initiative to ask some key questions," says Philip Leistner. "For instance, what features does an office space need to offer if it is to be profitably rented long-term? How do we manage the relationship among investors (buildings), operators (technical equipment) and users (interior arrangement) to ensure that workplaces protect health and encourage performance? What tools can we use to find the balance between profitable use of space and a setup that gets the best from employees? And how do we do that while maintaining communication and concentration levels in the workplace?"
The first step was to gather and define requirements. This was done using surveys as well as measurements on existing premises. It was also supplemented by further psychologically focused buildings surveys, investigations and research into the psychology of measurement methods conducted at the "High Performance Indoor Environment (HiPIE Laboratory)" at Fraunhofer IBP in Stuttgart. The parameters that most affect workers in offices include acoustics, the interior climate (relative humidity, temperature, air quality), and lighting. These concerns are now at the top of the Fraunhofer office initiative’s list of considerations.
No more listening in
Recent international surveys show that office users consider ambient noise to be particularly disruptive. "Low-level background noise is one of the triggers of increasing psychological stress in the workplace," says Dr. Andreas Liebl, Group Manager of Psychoacoustics at Fraunhofer IBP. Open-plan offices carry nearly twice the risk of employees contracting a short-term illness as opposed to single or two-person offices. Studies have shown that conversations that have nothing to do with a person and yet are involuntarily overheard have a significant negative impact on that person’s performance and concentration. This means a huge amount of disruption for any colleagues trying to work quietly within a roughly four-meter radius of the speaker, even in offices designed with acoustics in mind. The level of disruption depends not on the volume of speech, but on how well it can be understood. One way to get around this problem in a large open-plan office could be, for instance, to deploy the noise-masking floor lamp developed by researchers at Fraunhofer IBP in collaboration with their colleagues at the NIMBUS GROUP in Stuttgart. In this instance, masking means broadcasting another noise that conceals the disruptive chatter, making it harder to understand. Noise-blocking chairs and partitions featuring integrated noise-absorbing materials are another element of the solutions and projects being worked on by the Acoustics department at Fraunhofer IBP. It is an area that encompasses a great number of standards and guidelines, and yet if planners and architects were to rely on these alone, they would be a long way from realizing an acoustically effective office space. On the contrary, many of the regulations seem to contradict one another and haven’t been reviewed in 25 years and more. "That’s why we place such importance on relating our research to experience in practice," stresses Liebl. The world of work and the way offices are organized has undergone a seismic shift in recent times, and continues to evolve today.
Effective work spaces
When it comes to interior climate, here too it is no longer enough to rigidly follow current guidelines and stick to conventional office designs if we are to keep pace with the changes we have seen in flexible office usage and arrangement. Poor air quality is a significant disruptive factor in the office environment. An insufficient supply of fresh air and excessive concentrations of CO 2 are known to cause fatigue, headaches and problems concentrating. As well as sufficient air exchange, relative humidity is also an important factor – particularly in winter. Low indoor humidity has an impact on people’s susceptibility to infection, which ends up causing increased employee absence. Various interior climate studies have shown that usually almost half of the test subjects complain about dry air.
One of the challenges in offices used by multiple people is the subjective perception of interior climate. While one person might be freezing, it might still be too warm for another. What a man perceives as a pleasantly cooling breeze can be an irritating draft for a woman. If relative humidity is to be increased through lower temperatures, of course the number of people feeling chilly will increase. As a result, it’s important to come up with localized possibilities to compensate for this and retain motivated employees. Because of the increased demand for active humidification measures that assure comfort in office buildings using mechanical ventilation systems, there is an increased need for energy-efficient interior humidification systems that are able to satisfy the hygiene concerns of operators and employees. To this end, Fraunhofer IBP’s working group for "Thermal Comfort, Models and Simulation" from the department of "Energy Efficiency and Indoor Climate" has been carrying out experimental tests on a new high-tech membrane. As well as offering a high level of humidification thanks to selective diffusion, this solution is also a hygienic way to humidify air indoors because it avoids contact between water and the air and thus prevents the spread of germs. In order to achieve personalized and localized humidification at individual workplaces within spaces shared by many users, the researchers developed a localized air conditioning prototype that employs the " vortex ring effect." This air vortex displays only a minimal interaction with the surrounding air, meaning that the conditioned and humidified air can travel significant distances straight to the employee’s breathing zone. In summer, the problem of insufficient humidity is often turned on its head: now, warm, humid air makes it hard to work. Fraunhofer IBP has come up with an innovative, commercially available solution that uses radiation cooling, the Chilled Water Wall. This innovative panel cooling system cuts down on radiation temperatures with a cooled water film. By reducing temperatures beneath the dew point it is able to significantly reduce the relative humidity within the room and bind pollen and dust.
New lighting
LED technology has become an integral part of modern lighting concepts and is firmly established in the marketplace. The question is no longer whether LEDs will be used, but how and where. Large-surface light sources with reduced brightness and new design options are beginning to supplement existing lighting concepts. For instance, spaces that let in little or no natural light can be fitted with artificial windows. Here, LED systems reproduce the spectrum of sunlight and an optical system ensures a realistic perception of "sky" and "sun".
Fraunhofer IBP’s working group for Lighting Technology and Passive Solar Systems is contributing its expertise and laboratories to the office initiative. In the light testing laboratory, researchers are conducting performance and user acceptance studies examining the physiological and psychological effect of light, and testing innovative lighting concepts such as context-sensitive lighting. Taking into account the activities of the users of the space, they want to investigate how lighting systems can be operated with higher energy efficiency while maintaining or even improving acceptance levels. Variable control of natural and artificial light is another area of focus. At times when the office has more natural light, the artificial lights dim automatically, and vice versa. As a general principle, users prefer natural light over artificial light. There are significant improvements to be made in this regard relating to the various sun and anti-glare protection systems. The focus here is on the impact on workplaces with computer screens. Almost anyone who uses a screen knows that people make use of sun protection systems to prevent glare and not to conserve energy. The problem is that automatic systems are driven by energy concerns , which leads to dissatisfaction and distraction as users have to make their own manual adjustments. When too much artificial or natural light falls on a screen, it becomes hard to read what is being displayed. Accordingly, the researchers are looking at how to make the most intelligent use of natural light in office spaces.
Researchers at Fraunhofer IBP work on research-oriented innovations, developing techniques of calculation, simulation and analysis that often result in new patented technologies and products. "For us, it was only logical that we should pool our resources and expertise with partners from various areas," says Leistner, adding: "Good acoustics or a comfortable indoor climate can’t be achieved in isolation. We need to keep in touch with the market and its players if we want to truly make an impact." (taf)