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.

Source: Adobe Stock/Philipp Schilli

Invisible and in use everywhere

It is air that makes our blue planet unique. It is an indispensable means of life for man and nature. Clean air enhances our quality of life – at home, on the road, at work, during our leisure time – and is therefore one of the most valuable resources.

At the same time, air is used in industry and trade: as a means of transport for substances, for thermal and cold energy, in the form of compressed air and vacuum technology. In short, it is a tool for a wide range of purposes. In fact, compressed air is the second most important energy source in industry and is referred to as the fourth auxiliary material after electricity, gas and gasoline. Without compressed air, most of the products we use today could not be manufactured. Technology does not only use air as a tool, it also ensures the quality of the valuable resource in many places – and this usually goes on unnoticed behind the scenes.

We want to find out where we encounter air as a raw material or tool on a daily basis, both the kind we can and cannot see: Come with us on a journey of discovery as together we accompany the Bergmann family on a normal day full of air and air handling technology.

We can survive:
• Two months without food
• Three to four days without water
• Ten minutes without air. The brain function will stop after more than ten minutes without oxygen. After five minutes without air, the danger of apallic syndrome becomes real – a severe type of brain damage which leads to an irreversible vegetative state.

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.

During the night, the oxygen content can drop sharply – so fresh air is necessary in the morning. Source: Shutterstock/Artazum

Fresh air for good health

Source: iStock/Poike

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?

Source: iStock/JacobH

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.

Composition of air (volume share in percent)

Source: VDMA

Air consumption

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 health


















Mountain climbing




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.

Fans enable traveling underground Source: TLT-Turbo GmbH

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


mio. m³

Excavation volume of the tunnels under construction at the turn of the year


mio. m³

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.

Air handling technology extracts wood dust and shavings and creates safe and healthy working conditions. Source: AL-KO THERM GmbH

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.

Number of exceedances of the PM 10 daily average value of 50 μg/m with spots from country reports

Source: Umweltbundesamt 2016

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?

With these systems, impurities at the workplace are filtered out of the air and are disposed of. Source: Schuko H. Schulte-Südhoff GmbH
A look into the shavings collection funnel of a purge air filter system Source: Gerhard Bartling GmbH & Co.KG
The air must also be cleaned during furniture varnishing. Source: J. Wagner GmbH

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.

Copy with the kind permission of GTAI Germany Trade & Invest

Rolf Bernauer

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 environment

Source: Shutterstock/ Syda Productions

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.

Smoke extraction chimneys Source: BerlinerLuft Technik GmbH

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.

Whether large industrial systems or small vacuum cleaners – cleaning through air extraction is based on the same principle. Source: gettyimages/Denis Felix

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.

Compressed air is an important tool for the hygienic packaging of foodstuffs Source: Tegut GmbH Co. KG
Flour dust is fun when baking and a nuisance when packaging. Source: Shutterstock/ alexkatkov
Compressed air is also required to manufacture PET bottles Source: Shutterstock/ Pressmaster

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.

On the stove… Quelle: fotolia/osoloveika
….. like in industry: Extraction of aerosols – hard or liquid particles that float in the air Source: bp

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.

No coating process without vacuum technology – a look into the interior of a vacuum pump Source: Pfeiffer Vacuum GmbH
Vacuum technology is useful for coating – what the inside of a vacuum pump looks like Source: Pfeiffer Vacuum GmbH

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.

Air for man and machine

Air as an elixir of life will become increasingly important in the future. Not only because the right indoor climate is so important for our well-being, motivation, commitment and productivity. Air is also an essential raw material and tool in our modern industrial and service society. Products from the mechanical and plant engineering sector enable quality of life, while manufacturers also gain good business opportunities. In Germany each year, components, devices and systems for improving air quality with a total value of EUR 7.2 billion are manufactured; for compressors, compressed air and vacuum technology alone, the annual market volume is EUR 2 billion.

The authors

Christoph Singrün

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.

Ingeborg Eisenberger

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.

Bettina Kessel

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.

Links for more information

Fresh air in the workplace (cooling lubricants)

Guidelines and suggestions for the best technical solutions to make workplaces on machine tools more safe for man and machine by sucking out cooling lubricants/aerosols.


Relevant standards and policies of the VDMA dust extraction technology working group

Operators of technical systems, in which hazardous substances such as dusts, smoke, gases or aerosols are released, are subject to a statutory operator responsibility for the protection of workers and the environment. An overview of the standards and policies explains the health, fire or explosion risks that exist in the handling of dusts and which technical measures can be taken to avoid and reduce these risks.


Detecting air pollutants in the workplace

Many industrial as well as manual processes release hazardous substances. The guideline describes the best technical solutions, according to the German Hazardous Substances Ordinance, for how substances which do not belong in breathing air, are to be sucked out directly at the place where they are released or developed in order to protect humans and the environment.


Information on air pollution control and on air conditioning and ventilation technology in VDMA


Air recirculation in smoke and dust extraction

Highly effective extraction systems keep habitats and workplaces pure from dusts and smoke, but large amounts of air also allow valuable thermal energy to escape. The guideline describes the best technical solutions for the efficient and effective cleaning of extract air, so that it can be safely recycled into work rooms without heat loss.


Link to e-magazine “Pumps and Compressors for the World Market”

Further industrial application examples for the tool “air” are presented in the annual e-magazine “Pumps and Compressors for the World Market”. A free subscription is possible through the VDMA Verlag.


Link to compressed air model calculator

The compressed air model calculator gives industrial companies quick and interactive guidance on whether their compressed air systems are running in an energy-optimized manner and on which measures to implement to save energy and costs.


Link to the EcoLexicon

The EcoLexicon of the VDMA Compressors, Compressed Air and Vacuum Technology Association provides planners and operators of compressed air and vacuum systems with information on the optimized operation of their systems – from planning, financing, control and value retention to relevant national and international standards and laws.