Natural ventilation reduces the risk of infection by aerosols – Fresh air increases the ability to concentrate and improves the work atmosphere.
If several people are spending longer periods of time in an enclosed space, used air must be regularly expelled and sufficient air exchange must be ensured. Ventilation systems from D+H provide fresh, healthy air at all times of year. These systems use time-controlled, automated ventilation to reliably remove hazardous aerosols. When natural ventilation is used, differing exterior and interior temperatures as well as wind pressure ensure the necessary air movement and the desired air exchange. A D+H solution for controlled natural ventilation (CNV) makes this possible at significantly lower investment and operating costs than when a ventilation or air-conditioning system is used.
In autumn and winter we tend to increase the amount of time we spend indoors. In the coming months, restaurants, sports facilities and other enclosed spaces like schools and offices are bound to see an increase in the number of people present inside them at the same time. Fortunately, even in exceptional situations – such as the current coronavirus pandemic – a safe and healthy climate can even be created indoors by means of ample natural ventilation.
Natural ventilation guarantees the required air exchange.
In spaces where few people regularly spend time, extensive ventilation with a simple D+H ventilation solution creates this effective air exchange. In this process, stale air and aerosols are replaced with fresh air that has a higher oxygen content. The frequency and duration of ventilation can be specifically defined based on the time of year and weather. Intelligent ventilation systems respond to different parameters, such as room temperature, the CO2 content in indoor air, the outside temperature or sudden precipitation outside. Of course, the ventilation can also be time-controlled, for example in the form of a ventilation purge before work begins. And for all those who feel uncomfortable when there are no windows that can be opened by hand, there are buttons and remote controls that offer the individual convenience of adjusting the window drives.
Natural ventilation enables companies and restaurants to remain in business and ensures the operation of schools and other public institutions.
Big rooms where large numbers of people gather on a regular basis should be intensely ventilated at short intervals. In certain cases it may even be necessary to ventilate continuously. Intelligent ventilation solutions from D+H are capable of providing effective air exchange, and thus a safe atmosphere, at all times – even in complex ventilation scenarios in large buildings. "Using a D+H digital control panel we can reliably connect all components, such as window drives, sensors, timers, regulators and buttons," says Maik Schmees, Chief Technical Officer (CTO) at D+H Mechatronic AG. "The control panel communicates directly with the building management system and even ensures standard-compliant smoke extraction from the building in case of fire."
Better air hygiene in lift cars ensures well-being.
Even in the tight space of a lift car, effective air exchange is achieved by means of adequate ventilation through the lift shaft. Sensors attached to the lift car continuously check the air quality and temperature in the lift. The presence of people in the lift car is detected, as are the movements of the car in the shaft. The D+H ventilation solution from the BlueKit brand uses this information, depending on the actual use of the lift system, to control the flaps outside. Then the stack effect, or a fan mounted at the lowest level in the lift shaft, effectively discharges contaminated air to the outdoors.
Removal of aerosols by means of regular air exchange
In rooms with automated ventilation, wearing a cloth face mask and adhering to the rules of hygiene and social distancing are complemented by the most effective component: stale air is replaced with fresh air from outside and aerosols are effectively removed. The most critical factor here is the amount of air replaced during ventilation. The required air exchange rate is always significantly higher whenever there are a lot of people in a room at the same time, such as in a classroom or restaurant, or when people are engaging in physically demanding activities. This is true in sports halls and in large rooms where there is a lot of loud talking, such as at a sporting event or a choir rehearsal.
Time-controlled, automated ventilation
Controlled natural ventilation can reliably provide the required sense of well-being in any situation. This is especially true with respect to ensuring the correct room temperature and minimising heat loss during the heating season.
Products from D+H feature ventilation solutions for providing a wide variety of spaces with fresh, healthy air at all times of the year – with considerably lower investment and operating costs than when a ventilation system or air-conditioning system is used. The study KonLuft – Energieeffizienz von Gebäuden durch kontrollierte natürliche Lüftung1 (English: Energy efficiency of buildings using controlled natural ventilation) confirms the practical suitability of these ventilation solutions.
Filter systems of existing air-conditioning systems are usually insufficient
A solution from D+H for controlled natural ventilation of rooms and buildings provides critical advantages, even when compared to air-conditioning systems. Particularly with regard to the risk of infection by microparticles (aerosols) that are suspended in the air, sometimes for hours at a time, the advantages of ventilation become obvious. As can be seen from publications by the German Federal Ministry of Labour and Social Affairs (BMAS)2 and of the German Environment Agency3, air-conditioning systems are at a disadvantage here for two reasons. First, a ventilation system (HVAC system) frequently does not feed in enough fresh air from outside. As a result, the air exchange rate remains extremely low. Such systems only cool the indoor air and then circulate it continuously, almost like in a closed system. Second, these systems are usually only equipped with two-stage filter systems. But only highly efficient, expensive HEPA filters reliably guarantee that infectious particles are kept out of the indoor air. That is why HEPA filters used to be installed only in air-conditioning systems for particularly sensitive rooms, such as operating rooms.
Controlled natural ventilation reduces the risk of infection – even in the coronavirus age
State-of-the-art ventilation systems can significantly reduce the risk of infection caused by virus-contaminated aerosols in spaces used by many people. This assumes that they are installed and operated according to requirements. In the coronavirus age, this means continuous air exchange with high outdoor air flow volumes while minimising the amount of recirculated air. Overflow from a room equipped with an air-conditioning unit into a neighbouring room must also be prevented. "CNV systems with electrically-motorised windows offer an efficient concept that is also safe in respect of coronavirus aerosols," says Christoph Kern, Chief Sales Officer of D+H Mechatronic AG. "These systems combine the highest demands for indoor air quality, hygiene, comfort and flexibility with low primary energy needs and reduced investment and operating costs." Another advantage is the wide range of possible applications: these include office, industrial and residential buildings, restaurants, hotels, hospitals and nursing homes, as well as learning, sporting and leisure facilities. "As a result, they have the potential to be an important building block in preventing the rise of local areas of infection, particularly in public and commercial buildings. They are also making an important contribution to the ongoing containment and successful control of the coronavirus pandemic," states Kern with confidence.
You can find more detailed product information about Natural Ventilation here.
1 1 Stuttgart Technology University of Applied Sciences, in collaboration with project partner ZVEI (German Electrical and Electronic Manufacturers' Association), project sponsor German Federal Ministry for Economic Affairs and Energy (BMWi) and project sponsor Jülich (PTL), KonLuft – Energieeffizienz von Gebäuden durch kontrollierte natürliche Lüftung, URL (as of: 2016-10-31)
2 German Federal Ministry of Labour and Social Affairs, SARS-CoV-2-Arbeitsschutzregel, pages 8-9,
URL (as of: 2020-08-11)
3 German Environment Agency, Stellungnahme Kommission Innenraumlufthygiene zu Lüften und SARS-CoV-2, URL (as of: 2020-08-13)