Hygienic inspections of HVAC systems according to VDI 6022

The required quality of the air that is supplied by an air conditioning plant and therefore the requirements that the plant itself must satisfy depend essentially on what the rooms are to be used for. If an air conditioning system supplies air to workplaces it is automatically subject to labour protection laws and the subordinate regulations and so must be permanently kept up to date from a technical point of view. The current governing regulations are the German VDI 6022, whereby it is obligatory to implement these regulations.

The German labour protection laws (Section 4) also require the proper functioning of air conditioning plants to be regularly checked. The plants must supply healthy air and operate reliably.

Within the scope of VDI 6022 this inspection corresponds to the hygiene inspection and must be carried out for air conditioning plants every two years (systems with a humidifier) or three years (systems without a humidifier). The inspections of the equipment must be performed by qualified persons and satisfy certain minimum requirements to ensure legal compliance in all cases. The DMT hygiene inspection satisfies these requirements. Our range of services includes:

Appraisal of air conditioning equipment and components with regard to

  • adherence to design requirements as laid down in VDI 6022
  • operation, damage and pollution
  • functional aspects

Physical atmospheric parameters measured at representative sites

  • Temperature
  • Relative humidity
  • CO2 content
  • Air movement
  • Acoustic pressure level
  • Flow volume of ambient air

Microbiological investigations measured at representative sites

  • Determination of the bacterial count in air conditioning equipment
  • Bioburden and Legionella bacterium (Legionnaire’s disease) in water (humidifiers, cooling towers etc)
  • Germ content in the air supply as well as reference measurements of the ambient air

If your building is subject to the Technical Inspection Regulations (refer also to initial acceptance and subsequent checks based on the German Technical Inspection Regulations (Tpr¸fVO)), our specialists can carry out the required checks in combination with a hygiene inspection. This results in considerable cost savings for you. 


Rainer Peglau

Tremoniastraße 13
44137 Dortmund

Tel +49 231 5333-207
Fax +49 231 5333-299


FAQ - VDI 6022: Hygiene requirements for air conditioning systems and equipment

Air-conditioning (RLT) systems and equipment are found in a variety of buildings in numerous properties. As a central component of building technology, they perform tasks which are dependent on the pure ventilation / air-conditioning function, For example, in numerous office buildings, compliance with production-related requirements (eg in print shops), as well as hazardous waste collection as a pure safety function.

Together, they have the direct or indirect influence on the air quality and thus the air quality of the air. Defects in these systems and devices are therefore always associated with health risks for the space users.

To avoid these risks, the directive describes VDI 6022 hygiene requirements for indoor air-conditioning systems and equipment safety requirements relating to manufacture, planning, construction, maintenance and operation.

What are the risks of hygienic shortcomings in HVAC systems and equipment?

The risk of adverse health effects for the users of technical ventilated rooms depends on physical, chemical and biological hazards. As a result, they can lead to disturbances of the condition caused by train phenomena, concentration disturbances, Symptoms.

Thus, there is no "classical" disease, but impairments, which lead above all also to significant performance reductions of humans. Significantly more serious are, however, infections, Eg by legionella in air humidifiers.

Another disease caused by airway systems is the so-called exogene allergic alveolitis, which has been recognized as a "humidification lung" since the 1980s.

Where is the guideline VDI 6022 valid?

The VDI 6022 applies to all systems and equipment the rooms or areas of residence in rooms with supply air, in which according to the intended persons more than 30 days per year or regularly longer than two hours per day.

This is not restricted to workplaces only, but applies, e.g. Also in meeting places or hotels.

The scope covers all HVAC systems and devices and their central and decentralized components, which influence the quality of supply air.

Exceptions are recooling plants, for which there is a separate set of rules with VDI 2047 part 2.

For exhaust air systems the VDI 6022 only applies if these can influence the supply air quality by means of circulating air.

Is there a legal obligation to implement the VDI 6022?

In the case of an HVAC system or a device that ventilates a workplace, the statutory obligation exists to ensure that it is properly maintained at regular intervals and to check its operability.

This must be done according to the state of the art, which VDI 6022 describes as a technical rule.

It follows that an operator must implement VDI 6022 or, alternatively, take equivalent measures, but the effectiveness of which must be documented.

Finally, the VDI 6022 is the safest solution for fulfilling the operating requirements!

What are the objectives of VDI 6022?

The Directive is primarily intended to protect the health of persons. Thus the directive tries to preserve our health. So a classic hygiene task.

For this purpose, VDI 6022 specifies hygienically justified structural, technical and organizational requirements with regard to the planning, manufacture, execution, operation and maintenance of HVAC systems and equipment.

As a result, the requirements are supposed to lead to a healthy indoor air quality, which is decisively determined by the supply air quality from the HVAC systems and equipment.

What are the requirements of VDI 6022?

The VDI 6022 describes physical, air-chemical and microbiological quality characteristics as the central requirements for the quality of supply air. In order to meet these requirements, certain requirements are already placed on the manufacturer of components.

For example, Eg no pollutants or the basis for germ growth. There is also a plethora of constructive and material requirements. This continues as far as planning is concerned, where, for example, Eg specifications for the arrangement of individual components. Subsequently, requirements for the erection are made, Eg access to the plant and cleaning.

The requirements for maintenance and operation are described extensively in a checklist. This contains all hygienic-relevant tasks, including the deadlines for their implementation. This includes e.g. The regular determination of the germ count in the humidifier water. In addition to the tasks of functional maintenance such as, For example, VDI 3810 Part 4, VDMA 24186 Part 1, AMEV 430 or the specific manufacturing specifications, VDI 6022 forms the essential basis for the maintenance obligation laid down in the Workplace Ordinance.

What requirements for the qualification of the personnel for HVAC systems is laid down by VDI 6022?

In principle, the VDI 6022 requires an additional qualification in the form of hygienic training from everyone who works with HVAC systems and equipment.
A distinction is made between hygienic training according to type B (1 day), hygiene training according to type A (2 days), a briefing (for operators of small plants) and the VDI certified engineer RLQ.
The type B hygiene training is to be repaired or operated for all persons who are waiting for HVAC systems.
People who perceive the design tasks, construct, assume responsibility or carry out hygiene inspections need a hygienic training according to type A.

Do you have more questions?

Just call or write to us. We are happy to help.