Clean air for cities worth living in
Contributing to healthcare
Air pollution - The invisible danger
91 percent of the world's population lives in places that exceed the air quality guidelines of the World Health Organisation (WHO). Around 4.2 million deaths per year worldwide are attributed to air pollution, according to the WHO. The most dangerous pollutants in urban air are particulate matter, ground-level ozone, nitrogen dioxide and sulphur dioxide.
The best way to achieve clean urban air is to avoid emissions from the outset. Unfortunately, this is not achievable in the short run because alternative solutions often have yet to be developed and because a complete ban on emissions e.g. from traffic would have negative impacts on the economy and society.
Given the massive negative consequences of air pollution, wait-and-see is not a good strategy.
Technical outdoor air cleaning offers a pragmatic solution and is available now.
Product
City Air Cleaner
The City Air Cleaner filters up to 85 percent of harmful ambient pollutants such as fine dust particles and gaseous substances like nitrogen oxides, and ground-level ozone from the ambient air and creates a comfort breathing zone with better air quality.
The casing design can be executed to match customer's needs:
- neutral design corresponding to the installation site
- corporate branding for company premises
- luxury variant for exclusive working and living environments

Several City Air Cleaners work in combination to form a modular, scalable system for active management of urban air quality. Simulations of the real environment are used to determine an effective tailor-made air filter solution - for emission hotspots and constructionally and meteorologically caused accumulation points for pollutants.
The large infoscreens on the sides of the City Air Cleaners allow for local air quality infotainment as well as local traffic and event information or third-party advertising.
The City Air Cleaner is universally applicable. There are different models for tailor-made air cleaning solutions:

Model S
The high-performance City Air Cleaner S-60 can filter up to 60,000 cubic meters of ambient air per hour, the equivalent volume of 1.800 standard containers. It was developped for outdoor application and can be used also indoors.
- Customised filter system for optimal cleaning performance
- Large airflow volume with powerful air intake and smooth air outlet
- 24/7 availability with demand-driven control
- Integrated LED screen for infotainment or local advertisement

Model M
The compact City Air Cleaner M-20 is suitable for outdoor and indoor applications. It cleans up to 20,000 cubic metres of ambient air per hour.
- Customised filter system for local mixture of pollution
- High cleaning volumes with limited setup space
- 24/7 availability with demand-driven operation
- Integrated LED screen for infotainment or local advertisement
Test Model S-40
The Test Model S-40 is regularly used for practical tests under real conditions. These are accompanied by measurements of the local pollutant load and cleaning performance and serve as a basis for the subsequent simulation of the optimum cleaning solution.

- Fully functional prototype for testing purposes
- Air cleaning capacity up to 40,000 cubic metres per hour
- Easy transportation and setup thanks to integrated running gear
- Autonomous battery operation
Applications
Urban pollution hotspots
For effective absorption of pollutants on a busy road, City Air Cleaners are ideally placed on both sides of the road
There are three different areas of application in which City Air Cleaners can make an active contribution to air quality management:
- Zones with particularly high pollutant emissions
Primary air pollutants such as car exhaust gases and fine dust caused by tyre or brake wear can be directly attributed to the polluters. Avoiding them is the best solution. If this is not possible, it is best to remove them directly at the point of emission. By directly extracting and filtering out the primary pollutants from the ambient air, the formation of secondary air pollutants is also prevented. Zones with accumulation of high concentrations of pollutants
In complex reactions in the atmosphere, additional gaseous pollutants and suspended matter are formed from primary emissions. The accumulation and distribution of these pollutants depends directly on weather conditions. Elevated levels of particulate matter are a problem, especially in winter when weather conditions are poorly exchanged. Unfavourable structural constellations can also contribute to this phenomenon.- Zones with increased air quality requirements
Children and elderly persons, as well as people with respiratory diseases such as asthma, are particularly vulnerable in large cities due to poor air quality. Creating comfort breathing zones with better air quality in heavily polluted places where these groups of people regularly spend long periods of time, such as schoolyards, playgrounds, seniors residents, or public transport stations, is a good investment in health and well-being.
Working principle
Active contribution to air quality levels

The City Air Cleaner achieves the best air quality management effect directly at the point of emission. On a busy road, the device can extract the fine dusts and nitrogen oxides emitted by the vehicles directly at the source and filter them out of the air stream. This prevents the harmful pollutants from spreading into the environment.
The cleaned air is slowed down and released on the other side of the City Air Cleaner. The constant flow of freshly cleaned air improves the ambient air on the pavement by displacing the existing polluted air immediately behind the city air cleaner. At the same time it dilutes the prevailing pollutant concentration in the ambient air on the outlet side.
Intake behaviour using a smog machine
Benefits
Reduce elevated pollutant concentrations
City Air Cleaners help to reduce elevated pollutant concentrations locally in the short term and reduce further spread. At the same time, they ensure that filtered air is supplied to endangered immission locations.
- Available technology
to immediately and actively reduce the pollution of the population in places with particularly poor air quality - Active contribution to meeting statutory air quality standards
in zones with excessive air pollution in relation to the prescribed values - reduction of local pollutant concentrations
by direct extraction of the pollutants at source - Reduced generation of secondary air pollutants
through the direct extraction of primary pollutants - Measurable improvement in air quality
in the vicinity of the city air cleaners by effective filtering of pollutants from the ambient air sucked in - Reduction of pollution in the air we breathe
in the sphere of action of city air purifiers by active dilution of the ambient air
Technology
Innovative solution with proven technology
The City Air Cleaner represents an innovative solution for the effective technical cleaning of air volumes contaminated with pollutants for defined zones in urban environments. When designing the filter technology and air duct, we rely on best-in-class technology from internationally renowned filter and ventilation manufacturers.
Advantages
Overview


Effective
A proven 85 % reduction of toxic substances in the air absorbed – both nitrogen-oxides and particulate matter

Modular
Multi-stage filter system for flexible adaptation of filter media to specific local contamination scenarios

Mobile
Flexible and easy to erect without foundation and ready for operation at short notice

Intelligent
Demand-driven control of the system with monitoring of the operating performance for preventive maintenance

Low-noise
Demand-driven operation taking into account local noise pollution

Effective
A proven 85 % reduction of toxic substance in the air absorbed – both nitrogen-oxide and particulate matter


Modular
Multi-stage filter system for flexible adaptation of filter media to specific local air pollution scenarios

Efficient
Ideal ratio of cleaning performance to power consumption, operating and maintenance costs

Mobile
Flexible and easy to set up without foundation and
ready for use at short notice

Intelligent
Demand-driven system control and monitoring of the operating performance for preventive maintenance

Low noise
Demand-driven operation
taking into account
local noise pollution
Reference
Success Stories
Purevento wins first European tender for urban air purifiers
Kiel is a Northern German state capital and an important intermodal transport and tourism hub in northern Europe for cruise ships, ro-ro ships and passenger ferries from Germany to Scandinavia and the Baltic Sea, alongside the world's busiest artificial waterway, the Kiel Canal.
Kiel is also one of the cities in Germany that has so far failed to comply with the required pollutant limits at all local hotspots. At the beginning of 2019, Purevento successfully tested its prototype of the City Air Cleaner under the supervision of the Schleswig-Holstein State Environment Agency and the city authorities at the city ring road Theodor-Heuss-Ring. The city of Kiel installed six Purevento City Air Cleaners in October 2020. Thus, Kiel wants to comply with the required average annual limit value for nitrogen dioxide of 40 micrograms per cubic metre on this main traffic axis without having to impose driving bans.

Installation of 6 City Air Cleaners on Theodor-Heuss-Ring, Kiel (Picture: LH Kiel)
Customised solution
We offer modular, scalable air purification solutions for actively improving air quality in places with particularly high concentrations of pollutants in the air at main traffic axes and junctions or for use in areas with special air quality requirements.
For each location, we create a demand-oriented air purification concept using chemical reaction models and dynamic airflow analyses of the local conditions, which also include wind and weather data.
We are happy to advise you:
FAQs
Frequently Asked Questions
How does the City Air Cleaner work?
The contaminated ambient air is actively drawn in and cleaned of particulate matter and gaseous pollutants such as nitrogen oxides in a multi-stage filter process. The cleaned air is then released into the environment.
The cleaning performance of the city air purifier is determined on the one hand by the filter performance and on the other hand by the volume flow. It determines how much air is actually filtered and freed from the pollutants present. The good cleaning performance with efficient operation is the result of proven technologies and patent-pending innovations.
Where do City Air Cleaners make sense?
Wherever the air is heavy with harmful concentrations of pollutants, City Air Cleaners can help to immediately improve local air quality.
In many cities, traffic-related pollutant emissions are a major problem, affecting air quality in neighbouring residential areas and where people with sensitive health, such as children, live. City Air Cleaners can improve the air quality at such local emission related-pollution hotspots.
High concentrations of particulate matter in the air also pose a major health risk, especially in inverse weather conditions. City Air Cleaners equipped with an appropriate filter system are able to create local breathing zones by flooding them with purified air.
What is required for installation?
City Air Cleaners can be installed anywhere. All you need is a firm, level surface - a foundation is not required. The energy supply is provided by an external power connection. In any case, the City Air Cleaners are ready for operation within a short time.
What noise is to be expected?
The City Air Cleaners are designed in such a way that the noise development is minimised in relation to the cleaning performance. When installed on a busy street, traffic noise is usually predominant. Local noise protection regulations are of course observed. In demand-oriented, energy-efficient operation, City Air Cleaners only become active when and to the extent required by local pollution - for example during rush hours.
How strong are the air flows of a City Air Cleaner?
The intake airflow of a City Air Cleaner is strong enough for effective air filtration and corresponds to a weak breeze. The cleaned air is distributed and slowed down on the outlet side before it flows out gently as a light breeze.
Where can I experience a City Air Cleaner in operation?
An air filtration plant consisting of six City Air Cleaners S-60 for the purification of traffic-related air pollutants is located on the city ring road in the state capital of Kiel.
You can see other models in action in Trittau, just outside Hamburg. We would be pleased to inform you about the current status of further installations. If you are interested, please contact us by e-mail.
What does a City Air Cleaner cost?
Depending on the air pollution and the aim of air purification, we will be happy to provide you with an individual offer for a tailor-made air filtration plant with our City Air Cleaners for your personal concern for improving air quality.
We look forward to your enquiry.
What does the brand "Purevento" stand for?
Our brand name "Purevento" is composed of the terms "Pure" for 'clean, fresh' and "vento" for 'wind'. This combination of words stands for the air-purifying effect of a fresh breeze that helps to lower the concentration of air pollutants - just like Purevento's City Air Cleaners.
Should air pollution better be avoided instead of cleaning air afterwards?
Preventing and reducing harmful air pollution must be a priority objective of all clean air efforts. However, this is a long way off:
As long as cars are powered by combustion engines, the air will be polluted with solid and gaseous pollutants. Even purely electric road transport would still produce particulate matter due to tyre and brake wear.
Air pollution from households, industry and agriculture regularly causes dangerously high concentrations of pollutants in the air - especially particulate matter - in many countries. Transnational effects are often added to this.
In many places, therefore, an interim solution for better air quality makes sense. City Air Cleaners are a bridging technology that provides short-term relief until the causes of air pollution have been sustainably eliminated.