Air – breath of life, raw material, tool
Without air, our planet would not be blue. Life on earth would not be possible either. Technology not only ensures that we have pure air at work and at home, but also uses air as a versatile tool – with examples from the hair dryer to innovative tumor treatment.
No second without air
The Bergmann family is made up of father Wolfgang, mother Vera and their fifteen-year-old daughter Amelie and twelve-year-old son Jonas. The family lives in a single-family house in the green belt of a major city. Wolfgang Bergmann is an engineer while his wife works as a doctor in the radiation oncology department of the regional hospital. Like the average European, the family spends nearly 90 percent of time in closed rooms.
6.00 am: The day begins
Once Vera has dragged herself out of bed, she first goes to the window in the bedroom and opens it wide. She breathes in the fresh, cool morning air. This does a lot of good but is also necessary, since a lot of oxygen is consumed when sleeping at night. With every exhalation, the oxygen in the air is reduced to approximately 17 percent, while at the same time, around 4 percent CO2 (carbon dioxide) is produced. In closed rooms, the CO2 content therefore rises very quickly, and reduces the quality of the indoor air.
Air keeps our physical functions working in many ways. Fresh, clean air ensures the oxygen supply to the brain and promotes concentration. The immune system is also strengthened and respiratory tract infections are prevented – in this respect, fresh air acts as a germicide. A few deep breaths of clean air can vitalize the blood, and whoever gets plenty of fresh air before going to bed will benefit from deeper sleep. And with the right breathing technique, air can help us to relax.
• The surface area of the human lungs corresponds to the size of half a tennis court.
• We only breathe through one nostril at a time; we change over nostril around every 15 minutes.
• When we cough, the air in the lungs accelerates to about 100 km/h. Some sources claim this is really 200 to 300 km/h.
• Adults breathe in and out about 15 times per minute, children 20 to 30 times, babies 40 times.
What exactly is air?
The air we breathe contains oxygen and nitrogen as well as traces of the noble gases argon, helium, neon, krypton and xenon. Carbon dioxide, methane, hydrogen, nitrous oxide (laughing gas) and carbon monoxide are also components of air.
One liter of air weighs approximately 1,293 grams. 1 cubic meter, i.e. 1,000 liters, weighs 1,293 kilograms.
A human being breathes on average about 8 liters of air per minute. In a lifetime, this can be translated into more than 400 tons of air that flow through the lungs.
Source: Jan Wagner, Heinrich-Heine-Universität Düsseldorf
Depending on the activity, our air consumption fluctuates heavily:
Fresh air for good healthREAD MORE
7:15 am: On the subway
While the children are still sitting and eating their breakfast, Vera Bergmann is already on her way to work. She uses the escalator to get to the lowest subway platform. The fact that passengers have enough air to breathe underground is thanks to technology: The station is ventilated by central ventilation systems, meaning primary filtration is at work. Outside air is treated and repeatedly extracted by simple ventilation.
The air flow is also important in other traffic tunnels. The size of the volume flow of air depends on the size of the load using the tunnel. In a car tunnel, this means the traffic flow, i.e. the number of vehicles, as well as their CO2 emissions. For example, for a 3-kilometer-long tunnel and a traffic flow of 2,000 cars per hour in each direction, the required outside air volume is 3 040 000 m³ per hour or 844 m³ per second. This corresponds to approx. 280 m³ per second for each kilometer – a considerable flow of air, whose weight per hour is approx. 4 tons.
Tunnel construction in Germany
Traffic tunnels include tunnels for the subway, light rail and rail, as well as long-distance railway tunnels and road tunnels. For 2014, the following figures were recorded in tunnel construction:
Source: Stuva e.V. Statistik (2014/2015), Analysis and Outlook
Excavation volume of the tunnels under construction at the turn of the year
Excavation volume of the projected tunnels at the turn of the year (future demand)
Will be naturally ventilated.
(Estimation T. Damm, VDMA)
will be mechanically ventilated.
Good air and safety in tunnels
Ventilation not only ensures the necessary exchange of air in tunnels, but it also guarantees safety. For example, warm fumes generated during fires are extracted and routed outside.
7:30 am: On the way to work and school
For Wolfgang Bergmann, it is time to get going. He gets into the family car with his children. His car is fueled by biogas. Wolfgang drives past a biogas plant on his way to work everyday.
A whole range of raw materials can be used for the production of biogas, including biological waste, grains or corn. For a long time, biogas plants were only economically viable when they were geographically close to the user; wide distribution has only become possible by feeding biogas into existing natural gas grids. This is achieved through the application of compressed air: With the help of compressors, the biogas produced in modern plants can be fed into the city’s natural gas high-pressure grids and can provide for roughly 25,000 households.
Biogas for the private household
Modern plants first process the delivered grains into bioethanol and then into high-quality biogas, which can be fed into the general gas grid – from there it goes directly to the consumers.
7:50 am: At school
The new building of the secondary school that Jonas and Amelie attend is only a couple of blocks from the biogas plant. Inaugurated only three months ago, the building was constructed according to the latest technical standards and contains state-of-the-art heating, air conditioning and fire protection technology.
In order to be able to listen, understand and learn well, our brain needs good air. Numerous studies demonstrate the correlation between the quality of the air and people’s ability to concentrate. Particularly in regions with sub-optimal outside air quality, technical ventilation with high-quality supply air filters is preferable to window ventilation. In modern low-energy buildings, as in the Bergmann children’s school, technical ventilation is indispensable for ensuring a high quality of the air inside.
Good air for bright minds
With good-quality air, learning is easier. Large and small fans in modern ventilation systems ensure that school rooms provide an optimal learning environment. Inside, the ventilation system is integrated into the building so that it is unnoticeable. The actual process is performed on the roof.
8:30 am: In the furniture factory
Wolfgang Bergmann’s workplace is close to the children’s school. He works as an engineer in a furniture factory, where he is responsible for the wood processing.
In the entire building where Wolfgang works, an optimized air exchange takes place. This not only ensures the right room temperature and a low CO2 content, but also optimal air humidity. Furthermore, the incoming air is cleaned of airborne particles, pollen and other harmful components. All necessary measures are taken to ensure high air quality in the workplace. In return, the factory has high-performance filter systems that allow only purified air to escape into the open air.
It is not only human beings who breathe – office buildings do too: The fans and filters are their lungs. For individual offices, air exchange rates are estimated to be at least 40 m³ per hour, for open-plan offices this is 60 m³ per hour per person. Thus, for example, an air-conditioned office building in which 100 people work uses 6,000 m³ of air in an hour. This means that around 22,000 tons of air is in circulation in a year – more than double the weight of the Eiffel Tower.
What is dust?
A distinction is made between suspended airborne particles, also known as fine dust, and settling dust. Airborne particles or fine dust float through the air and can easily be inhaled. This includes, for example, the dust that is created during the burning of candles, during frying or toasting, and from laser printers. Settling dust is coarser dust which results, for example, from clothes friction, ash exchange in the fireplace or home improvement work. It is also called house dust and settles on the floor and on surfaces.
Other substances also like to attach to dust. Biocides or plasticizers from furniture or paints are, for example, free of gaseous forms and can attach to the dust. In the case of house dust, mites and other microorganisms also play an important role. If the dust lingers around for a long time, a regular habitat is formed – unfortunately a good prerequisite for an allergy to house dust.
How does dust become airborne particles?
- Particles which fall below a certain size are referred to as airborne particles. This particle size is measured with a measuring device which contains a size-selective inlet with an aerodynamic diameter of 10 (PM10) and 2.5 (PM2.5) micrometers (μm) and an efficiency cut-off of 50 percent.
- The upper size limit of fractions of airborne particles in the air, referred to as fine dust, is 10 micrometers (micrometer = one millionth of a meter or one thousandth of a millimeter). (Source: UBA, Jahr der Luft)
- 5 μm is the maximum size of respirable airborne particles.
- Over 80 percent of EU citizens are exposed to airborne particle pollution. This figure is above that which is considered safe according to WHO’s 2005 air quality guidelines.
- 10 million particles are in one liter of air. (Source: UBA, Jahr der Luft)
The German Environment Agency provides more information.
Air in the workplace
Where wood is chopped, shavings will fall – and all kinds of particles fly through the air. This is also the case at Wolfgang Bergmann’s workplace in the furniture factory. Employees in other workshops, laboratories or the metal processing industry are also aware of this problem. The suction and dust extraction technology is as versatile as the substances, particles and gases, which pollute the air during the work. This technology must clean the air of harmful substances or pollutants, from shavings to the finest dust particles.
What is dust?READ MORE
Filters for the environment
In many parts of the world, the topic of clean air has been gathering ever more interest – even in industrial production. Industrialized countries are pioneers here, but other markets such as China or South America are following suit, explains Rolf Bernauer from Keller Lufttechnik GmbH + Co. KG.
What are products for air pollution control exactly?
In principle, we sell individual solutions. Should the customer have a problem with dust in production, the solution will be specifically adapted to meet his/her needs. One of the products is suction systems for the purification of emissions, this includes dust, smoke, aerosols and gases.
Are these solutions mainly required in industrialized countries?
Yes, they are the most important markets. This is why we offer extraction solutions exclusively for process emissions arising in production. We began in Europe, but the USA developed as a market at the same time. These regions were the first ones to raise environmental awareness. China has also been of interest for more than ten years. In the short term, we are lining up South America and in the long term, India.
Do the more stringent emission and environmental protection regulations drive industry exports?
In recent years, environmental interest has increased significantly in many parts of the world. In addition, the demand that customers are placing on themselves for clean production has increased. Legal requirements and the mindsets within companies go together.
Rolf Bernauer is head of the International Business Organization department at Keller Lufttechnik GmbH + Co. KG. The company produces and develops filter systems for practically all industrial areas.
VDMA has an Air Pollution Control Department within the Air Handling Technology Association.
9:30 am: On the school yard
It’s time for a long break at school. Amelie and Jonas meet up in the school yard and enjoy the fresh air. But fresh air is not always clean. Air, especially in urban areas, is also polluted by industry, traffic and heating. Despite all efforts, airborne particle pollution is therefore a big problem.
Filters for the environmentREAD MORE
9:50 am: In class
The bell rings to signal that break is over and the physics class is about to begin. But, a surprise awaits the children: The physics teacher has brought chocolate-covered marshmallows for all. Why? Today, Amelie and her classmates are learning about vacuums, including how they are generated. They will also learn of the effects of the absence of air on a chocolate marshmallow.
For this, the physics teacher attaches a vacuum pump to a bell jar. After opening the valve between the vacuum pump and the jar, the air is extracted from the jar so a vacuum is generated. As a result, the bubbles in the chocolate marshmallow expand and enlarge their volume many times over. When the air then flows back into the bell jar, the pressure which has an effect on the white foamy mass of candy is once again raised to the normal value. Thus, the chocolate marshmallow is returned to its original size, though is now somewhat dented.
A chocolate marshmallow in a vacuum
The chocolate holds the marshmallow inside. But only in “normal” air pressure. In the vacuum, the marshmallow bubbles can expand and burst through the chocolate cover.
11:00 am: In the hospital
While Amelie is learning about vacuums in school and nibbling away at chocolate, Vera Bergmann treats her tumor patients. She knows that air or the exact opposite, namely a vacuum, can be life-saving – as in the radiotherapy of malignant tumors.
An impressive example of modern vacuum applications is the particle or ion beam therapy of malignant tumors, for example in the head and neck area. In this process, protons or carbon ions are accelerated to a very high speed and then directed exactly to the tumor tissue. The particles damage the malignant cells irreparably. With this highly precise technique, tumors can be treated in a more targeted way than with older methods – without harming healthy tissue. The vacuum acts as a valuable tool, since all steps from the source to the radiation target are performed in a vacuum. As a result, the beam can be accelerated to high speeds, unlike natural air, and reaches the diseased parts of the body without any loss.
The importance of vacuum in industrial application
The vacuum is used as a tool in a variety of industrial applications. Here, it is classified into different pressure areas. These range from the so-called simple vacuum, which is used, for example, for robot gripping systems, to the ultra-high vacuum, which corresponds to the conditions in space.
11:30 am: At the airport
Wolfgang Bergmann has to take a plane to get to his business meeting – and he is also thinking about vacuums, albeit unconsciously: While waiting to board, he watches the airplanes that are chartering onto the runways. He looks at the big turbines and wonders how such a vital component of the aircraft is made with all its subcomponents.
Indeed, the requirements on the material of aircraft turbines are very high. The steels or alloys used must be hardened and/or refined. The heat treatment required in this process is carried out in a vacuum. In this way, for example, dissolved or unwanted trace elements are removed from metallic melts. Depending on the system or application, vacuum pumps with various operating principles are used.
While waiting, Wolfgang contemplates about security. What would happen if a fire broke out in the airport building? In this case, preparations are in place: An intelligent technology ensures that in the event of a fire, the smoke is led out of the building through mechanical smoke extraction systems in specially designed chimneys.
3:00 pm: On the school bus
While their parents are still at work, Jonas and Amelie have already finished at school and travel home together on the bus. When the doors open and close, they make a short “pfffff” sound – because here, too, air is at work: Compressed air.
Compressed air is simply air compressed beyond the atmospheric pressure. This pressure is achieved by compressors. Unlike in the case of liquids, compression always produces heat – this is noticeable when getting on and off.
4:00 pm: In the children’s room
Once the children have arrived at home, Jonas prefers to complete his homework straightaway. While he is tackling his numeracy, he eats a few biscuits and – oops – he has made crumbs on the floor. Jonas quickly grabs the vacuum cleaner to remove the crumbs. Without knowing it, Jonas is now performing exactly the same procedure that takes place in the factory where his father works during the extraction of the wood dust. However, in the factory, this takes place before the shavings and the wood dust reach the floor. The filter in the vacuum cleaner and in the large filter systems work according to the same principle. In both cases, the dust is disposed or recycled afterwards.
5:00 pm: In the supermarket
After finishing her work in the hospital, Vera goes to buy groceries at the supermarket. The quality of food is quite important for her – and here, too, compressed air is vital. For example, compressed air, whose purity is also precisely defined, is necessary for the transportation of flour from the mill to the packaging.
In the drinks aisle, Vera Bergmann automatically picks up the beverages with bottles made from polyethylene terephthalate (PET), because they are much lighter than glass bottles. Compressed air is also required for the production of PET bottles. The compressed air is used at high pressure (between 20 and 40 bar) as blowing air for the real production of PET containers. By varying the pressure, almost any number of different shapes of bottles can be produced.
6:30 pm: In the kitchen
In the evening, Vera Bergmann prepares a meal for herself and the two children. The French fries for Jonas and Amelie go into the convection oven and Vera fries a steak in the pan. Fortunately, the extractor hood eliminates the smell of the frying fat. Aerosol separation for machine tools in industry also works according to the same principle: Here, similar to frying, water and oil are simultaneously sprayed and are extracted, like from the pan.
9:00 pm: On approach
Wolfgang Bergmann is on his way back after a successful business meeting. During landing, he notices that only very few headlights are installed for the illumination of the runway at night. This is thanks to the high performance of the modern headlights. To enhance the intensity of the light, they have special reflectors which have been manufactured using vacuum technology.
Plastic reflectors for vehicle headlights are vaporized with an approximately 80 nanometer (nm) thick aluminum layer. The coating process is carried out under high-vacuum conditions. The vacuum is necessary so that the evaporating aluminum particles can travel the distance to the coating surface without colliding with other particles.
10:15 pm: Time to relax
Finally, a long day at work is over and the children are lying in bed. Vera and Wolfgang sit together on their sofa in the living room. They sit back to relax and enjoy a cool beer, which has of course been brewed according to the German purity law – and thanks to compressed air.
Without compressed air, there would be no beer to quench thirst. Breweries use compressed air almost everywhere. For example, for the valve controls in almost all departments, to clean the huge tanks or to ventilate the beer wort.
Pure compressed air for pure beer
There would be no beer without yeast. However, the brewing process must be properly ventilated. This is ensured by compressed air, which is also subject to a purity law – it must be oil-free. Modern systems enable this, and at the same time provide a significant reduction in energy costs.
Managing Director, VDMA Compressors, Compressed Air and Vacuum Technology Association
The industrial engineer has been Managing Director of the Compressor, Compressed Air and Vacuum Technology Association and the Pumps + Systems Association since 2005. He has worked for these industries in the VDMA since 1992. His key topics are research, technology, international markets, European standards and energy efficiency.
Dr. Thomas Schräder
Managing Director, VDMA Air Handling Technology
Managing Director of Air Handling Technology since 2003. The Association is the competence network for product groups and processes that focus on guiding, treating and conveying air. Air handling technology provides sustainability solutions as required by the climate protection policy of air handling technology components, and in particular by the building sector.
Assistant to the Managing Director, VDMA Air Handling Technology
Assistant to the Managing Director of the Air Handling Technology Association in VDMA since 2003. Clean air is an issue that we are committed to. This should be clarified with the multimedia report.
Assistant to the Managing Director, VDMA Compressors, Compressed Air and Vacuum Technology Association
The Business Administration graduate performed central management activities for the member companies of the Compressors, Compressed Air and Vacuum Technology as well as Pumps + Systems Associations from 2012 to 2017.