A breath of fresh air

Buildings can make us sick—and defective ventilation and air conditioning systems are often the cause. Bilfinger Berger hygiene experts and process engineers say that the air inside buildings deserves to be treated with the same care as the food we eat and have stepped up their close cooperation.

When researchers examined Ötzi, the mummified neolithic corpse found under a glacier, one thing in particular surprised them: his lungs were as black as a chain smoker’s. Tobacco didn’t exist in the Ötztal Alps 5,200 years ago. The explanation for Ötzi’s black lungs was that he suffered from a neolithic version of the so-called “sick building syndrome”.

Sick building syndrome refers to acute health-related disturbances that are caused by buildings: eye irritations, respiratory infections, drying mucous membranes and skin, mental fatigue, circulatory problems and headaches. The reasons for the symptoms have not been conclusively researched, but one thing seems clear: inadequate air hygiene is the primary cause.

This was Ötzi’s problem, too. He sat around the open fire of his dwelling every day, while the acrid smoke found its way into the air sacs of his lungs. Today, of course, the air inside buildings contains different irritants: poorly built or incorrectly adjusted ventilation and air conditioning systems trigger drafts and dry air inside rooms, spread odors, are too noisy and may even be contaminated with fungi or bacteria, resulting in allergies and infections. The result: physical and mental stress.

Plan well, maintain regularly and breathe easy
“Air is a foodstuff!” says Michael Sauerwein, Head of Building Equipment at Bilfinger Berger Building: “We have to pay attention to where we get the air that we pump into buildings, how we transport it and how we keep it clean.” Sauerwein is convinced that a prophylactic approach provides the best protection when installing ventilation and air conditioning systems. “That’s why we exchange information with our colleagues in Facility Services as early as the design stage.” In the Facility Services division, Bilfinger Berger has bundled all property and real estate service companies, including the HSG Group, a technical services provider—which is where Sauerwein’s contacts for environmental and hygiene technology can be found. “They explain to us exactly what we have to bear in mind when planning and installing a ventilation or air conditioning system so that it can be economically serviced and kept in sound hygienic condition.”Holger Pitzer, responsible for air hygiene at HSG, confirms this: “If you cut corners in the construction phase, you pay the price later. And if a building is designed in a way that the ventilation ducts are difficult to access, how can proper maintenance work be carried out?”

There are lots of ways, some of them quite simple, to ensure healthy indoor air, says Pitzer, it’s just a question of applying them. In Megaron in Mannheim, a modern office block with some 800 workplaces, built and now managed by Bilfinger Berger, the construction and facility management specialists jointly opted for nine smaller ventilation systems spread out over the roof instead of the installation of a single central unit. Powerful 15-kilowatt motors turn the ventilators, pumping 15,000 cubic meters of fresh air into the building hourly. “A central system would have had much longer air ducts. Now we have short ducts, which are much easier to inspect and clean,” explains Michael Sauerwein. He points out that this greatly reduces the risk of microbial layers forming at the seals. “It also helps that the units are on the roof,” adds Holger Pitzer. “They are easily accessible for the technician and the incoming air is less polluted by exhaust emissions.” What’s more, the short ducts also reduce electricity costs since the ventilators have a lower resistance level to overcome.

The smog stays outside
Twice a year, Megaron building technician Manfred Hotz changes the filters. He replaces the fleece inserts, tightens the screws and cleans the frames. It takes several weeks for him to service all nine units. Holger Pitzer, or one of his inspectors, regularly checks the state of the facilities in all of Bilfinger Berger’s buildings— and in particular the number of airborne germs. “The inside air should not be more contaminated than the outside air,” says Pitzer. And, generally speaking, the filtered air inside the buildings is indeed significantly cleaner than the surrounding air. Three women are standing outside Megaron’s main entrance, smoking their cigarettes, breathing the smoke deep into their lungs. After their cigarette break, they go back into the fresh air.

(Text: Bernd Hauser, Photos: Christoph Püschner)