Every third ventilation system in schools with significant defects

A good third of ventilation systems in buildings subject to mandatory inspection had significant defects in the Corona year 2020. This is one of the results of the Building Law Report 2021. The TÜV Association emphasises the central importance of ventilation and air conditioning technology for infection protection and points out retrofitting options.

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1 July 2021 - More than one in three ventilation systems (34.2 per cent) in buildings requiring inspection, such as high-rise buildings, schools, clinics or shopping centres, were found to have "significant defects" by TÜV experts in the Covid year of 2020. Compared to the previous year, the proportion has increased by 5.6 percentage points. Another one-third (31.5 percent) have "minor defects" and only 34.3 percent are "free of defects". This is one of the findings of the TÜV Association's "Building Law Report 2021".

"In the Corona pandemic, infections occur mainly indoors via aerosols," says Dr Joachim Bühler, CEO of the TÜV Association. "Properly functioning and optimally adjusted ventilation and air conditioning systems create a healthy indoor climate and help reduce the risk of infection in buildings." Ventilation and air-conditioning technology therefore has a central role to play in combating the pandemic, he said. "Especially in schools, there has been a failure to reduce the risk of infection with structural and technical measures," says Bühler. Instead, in many places, there will probably be intermittent ventilation every 20 minutes again in winter. "Ventilation systems can also be retrofitted in buildings or mobile air purifiers installed," says Bühler. During operation, it is crucial that ventilation and air-conditioning systems are regularly maintained, correctly adjusted and that inspection dates are scrupulously adhered to. Bühler: "In times of pandemic, the fresh air supply of ventilation systems should be increased and recirculation should be avoided in order to reduce the risk of infection."

In 2020, 17,896 ventilation systems were inspected by independent experts from TÜV companies during operation (up 3,948) and 2,236 for the first time (down 136). "The high number of complaints shows how important the mandatory inspections by independent bodies are in building technology," says Bühler. In addition to air conditioning and ventilation, fire protection systems and safety-relevant electrical systems are the focus of the inspections. According to the building codes of the federal states, the inspections are mandatory for so-called special buildings. In addition to high-rise buildings with a height of 22 metres or more, these include hospitals and nursing homes, schools, universities and other educational institutions, places of assembly such as congress halls or stadiums, industrial buildings, multi-storey car parks, hotels and sales premises with a floor area of 2,000 square metres or more. Across all areas, the inspectors found major deficiencies in just over one in four facilities (26.1 percent) last year. A further 44.3 percent had minor defects and 29.6 percent were free of defects. In addition to the periodic inspections, the systems are inspected for the first time before they are put into operation. In as many as 17 percent of the initial inspections, significant defects were found.  


A central objective of the inspections is fire protection. In 2020, according to the Building Law Report, a good one in five fire alarm systems in special buildings were found to have significant defects during operation (22 percent).  In the case of fire extinguishing systems, it was a good one in four systems (26.3 percent). Smoke and heat extraction systems also serve preventive fire protection by directing dangerous smoke to the outside in the event of a fire. In the previous year, significant defects were found in 27.7 percent of the smoke and heat extraction systems inspected. The so-called safety power supply is used to ensure the supply of power to safety-related systems such as fire alarm systems or smoke extraction systems in case of fire or other malfunctions. Last year, 23.9 percent of the systems for safety power supply were found to have significant defects. 

According to the TÜV Association, digital technologies can help to improve the functionality of safety systems in buildings. "If technical building systems have appropriate sensor technology, they detect malfunctions and weak points such as material fatigue at an early stage," says Bühler.  "The control and monitoring of the systems can be carried out efficiently via remote maintenance." In addition to systems requiring inspection, access and monitoring systems, building lighting or systems for improving energy efficiency are automated and digitally controlled. "With the increasing digitalisation of building technology, the risk of cyber attacks is rising," says Bühler. "It is important now to raise awareness of this problem both among project managers for new buildings and among operators of existing properties." In addition, checks on digital components would have to become an integral part of mandatory audits. Bühler: "The ball is in the legislator's court: testing organisations need access to security-relevant data as well as hardware and software in order to be able to monitor the full functionality of digital building technology."