VDI 6022-1 Ventilation and indoor air quality – Hygiene requirements for ventilation and air conditioning systems and units (VDI Ventilation Code of Practice)
The VDI 6022 series of guidelines applies to all rooms or areas and equipment used in rooms that are intended to be used by persons for more than 30 days a year or for more than two hours a day on a regular basis. VDI 6022 Part 1 applies to all ventilation and air conditioning systems and air handling units and their centralized or decentralized components (including units such as recooling plants) that affect the quality of supply air.
VDI 6022 shall apply to exhaust air systems if they can affect the quality of the supply air through recirculation.
Existing ventilation and air conditioning systems operate incompatibly within the scope of a proceeding permit in a manner comparable to that applied to structural fire protection. To ensure continued hygiene quality,
BusinessAny space occupied by employees for more than 30 days a year or more than two hours a day on a regular basis is considered a workplace.
Outdoor air flow rate: The flow rate of air flowing into a system from outside or directly into a room without conditioning.
Clean swept: The condition of a surface that has been cleaned, for example using a broom or brush, and can be called clean under visual inspection.
Notes: In case of disagreement about dust surface density on surfaces in contact with handled air and “clean sweep” classification, measurement is recommended.
Disinfection: Method aimed at reducing the number of living things
Decentralized air handling unit: Unlike a central air handling unit, this unit is dedicated to a single room and provides secondary air or outside air to that room.
Note 1: Examples of such units:
Note 2: See limitation below → decentralized façade mounting
Air control unit.
Decentralized façade-mounted air handling unit: This is a unit installed at or near the facade, allowing a short air path to receive outside air, i.e. through the facade or a window.
Notes: Examples of such units:
Terminal device: This device, which works with air from central air conditioners and, depending on the situation, also with secondary air, does not have its own mechanical drive to process the air.
Notes: This means that each terminal device is allocated to a single room. Examples of such devices:
partitions, cooling convectors, suspended cooling panels, etc.
The following can also be terminal devices:
Harmlessness to human health: A situation that means that health is not expected to be affected by the methods and technical systems used, their operation and maintenance.
Notes: This also means that the evaluation also takes into account possible synergies and mutual reinforcement. If necessary, an expert report is obtained from a recognized independent organization.
Hygiene: Measures that serve to protect and promote health as well as to prevent disease.
Hygiene Supervisor: Medical doctor or microbiologist specializing in hygiene (and/or environmental medicine), with at least as much knowledge of the functioning of ventilation and air conditioning systems as that provided by Category A training, with practical experience in the hygienic evaluation and examination of ventilation and air conditioning systems and their inspection results.
Hygiene Supervisor: Person qualified beyond Category A, through further training in accordance with VDI 6022 Part 4, Category RLQ, to carry out checks of ventilation and air conditioning systems and to carry out indoor air quality assessments up to Class 2 according to VDI 6022 Part 3
Hygiene specialist: A person who has in-depth knowledge in the fields of hygiene and microbiology thanks to relevant university studies and, if possible, professional experience in the field of medicine and knowledge about the functioning of ventilation and air conditioning systems at least to the extent provided by the category. Training and practical experience in the inspection of ventilation and air conditioning systems and the evaluation of the inspection results in terms of hygiene.
Hygiene inspection: Qualified survey of the hygienic state of ventilation and air conditioning systems.
Hygiene control: Periodic monitoring of the hygienic status of ventilation and air conditioning systems at short intervals.
CFU (colony forming unit): The unit in which the number of culturable microorganisms is expressed. [DIN EN 13098]
Critical consequence: The following are examples of critical consequences
Air hygiene: The branch of hygiene that deals with the interactions between humans and ambient breathing air related to health and well-being.
Microorganisms: In the context of ventilation and air conditioning systems, this term includes bacteria (such as legionella), algae, and molds that can grow in water or on moist surfaces (such as humidifier water or condensate).
Ventilation and air conditioning systems and air handling units: The sum of all components required for fan-driven ventilation of one or several rooms.
Notes: For the purposes of this guide, this also includes → centralized and → decentralized air handling units, → terminal devices, etc. It also includes system-specific assemblies such as
Existing ventilation and air conditioning system: For the purposes of this guide, any ventilation and air conditioning system installed before the publication of the relevant edition of VDI 6022 is considered an existing system.
Small ventilation and air conditioning system: A ventilation and air conditioning system of compact overall dimensions consisting solely of "filtering" and/or "heating" air conditioning functions and having the same user and owner/operator.
Secondary air: The volume flow of air drawn from a room and returned to the same room after conditioning. [DIN EN 13779, Table 2]
Recirculation air: Recirculated air is exhaust air that is returned to the air conditioning system to become part of the supply air of at least one room from which it is not drawn.
Reference weather: Minimum supply air quality.
Easy-to-maintain ventilation and air conditioning system: Such a system provides convenient access or permits visual inspection with reasonable effort.
Central ventilation and air conditioning system: Provides outside air or → recirculated air to several rooms.
This manual supplements the applicable regulations for the planning, execution, operation and maintenance of ventilation and air conditioning systems for hygiene purposes.
Periodic technical maintenance, functional and hygiene checks and periodic hygiene checks are very important.
*Supply air quality: Supply air will be harmless to human health and odorless. Odour-causing additives are not allowed, even at subconscious levels (beyond the threshold of conscious perception). An exception is made for methods that serve to maintain or restore the quality of natural outdoor air and systems in which building occupants accept such additives.
The required supply air quality depends on the reference air, the loads to be lifted and the selected air exchange rate.
*Reference weather: The minimum objective of the hygiene requirements, specified in VDI 6022 Part 1, is that the air quality is not impaired by the air handling unit or the ventilation and air conditioning system. Evidence of compliance with established objectives is determined by comparing the supply air with the reference air defined below.
Reference air corresponds to either healthy outdoor air or healthy indoor air in the occupied space or to an air quality depending on the mixing ratio.
Healthy outdoor air refers to the compliance of airborne contamination with the limits required for outdoor air (according, inter alia, to WHO or EU Directive 2008/50/EC, e.g. fine dust concentration).
Reference to healthy indoor air in the occupied space is given in the Occupational Health and Safety Act and workplace boundaries (AGW, formerly: MAK values) and, depending on the application, in the regulations on biological working substances and hazardous substances. When standard values for health protection or limit values based on technical parameters are not available, the minimum requirement is that the ventilation and air conditioning system should not impair the air quality in any space.
*Physical requirements: Working temperatures, indoor air humidity and air speed ranges for thermal comfort are given in ISO 7730, EN 15251, EN 13779 and in VDI 3802 for factories.
Noise emissions from the ventilation and air conditioning system must comply with the specific requirements of the intended use, such as the limits specified in VDI 2081.
*Air chemistry and microbiological requirements:
Ventilation and air conditioning systems will be planned, executed, operated and maintained in accordance with the technique to prevent the proliferation of microorganisms. All air handling areas shall be designed, operated and maintained to avoid an additional load by inorganic and organic pollutants as well as harmful substances.
Materials used in air handling units where high relative humidity values or large quantities of water are inherent in the intended use must not provide a nutritional substrate for microorganisms (evidence to be established in accordance with EN 846).
The content of supply air in organic, inorganic or biological components must not exceed the content of reference air in any category (see Section 3.3).
Seals in air handling areas shall have closed pores, shall not absorb any moisture or emit any odors, and shall not provide a particularly nutritious substrate for microorganisms.
According to VDI 6022:
The evaluation process according to the VDI 6022 Standard is defined below.
All components;
Selection: The hygiene-related selection and arrangement of the components draft of the maintenance concept draft of the hygiene-related performance specification specification of the requirement classes must comply with VDI 6022-1 and reference standards.
First hygiene inspection: All material components are checked for hygienic requirements. Materials such as adhesives, paint, plastic parts and rubber within the components must be tested according to ISO 846.
Design of products: It is necessary to ensure VDI 6022 compliant design of units and components and document deviations.
Setup: VDI 6022 compliant installation of all air handling unit components and units must be ensured and deviations must be documented.
Under certain climatic and environmental conditions, microorganisms can settle and colonize the surface of plastic or plastic products. Their presence and/or metabolic products not only damage the plastic itself, but can also affect the serviceability of building materials and systems containing plastic parts. The tests and test conditions specified in ISO 846 are empirical and cover most, but not all, potential applications. For specific applications and long-term testing, procedures are agreed upon that reflect performance under actual conditions.
The effects of microorganisms on plastics are affected by two different processes.
a) Direct effect: Degradation of plastics, which serve as a nutrient medium for the growth of microorganisms.
b) Indirect effect: effect of metabolic products of microorganisms, e.g. discoloration or further deterioration.
The ISO 846 standard specifies methods for determining the degradation of plastics by the action of fungi and bacteria and soil microorganisms. The purpose is not to determine the biodegradability of plastics or the degradation of natural fiber composites. The type and degree of distortion can be determined by:
a) visual inspection and/or
b) changes in mass and/or
c) changes in other physical properties.
The tests can be applied to all plastics that have a flat surface and can therefore be easily cleaned. Exceptions are porous materials such as plastic foams.
The ISO 846 standard uses the same test fungi as IEC 60068-2-10. Using so-called "pooled samples", the IEC method requires inoculation of samples by spore suspension incubation and evaluation of fungal growth as well as any physical attack on the samples.
The test volume and test strains used depend on the intended application for the plastic.
ISO 846 standard refers to the standards stated below.
ISO 13934-1:2013, Textiles — Tensile properties of fabrics — Part 1: Determination of maximum force and elongation at maximum force using the strip method
EN 10088-1, Stainless steels — Part 1: List of stainless steels
EN 10088-2, Stainless steels — Part 2: Technical delivery conditions for general purpose corrosion-resistant steel sheets/plates and strips
EN 13697:2015, Chemical disinfectants and antiseptics — Quantitative non-porous surface testing for the evaluation of the bactericidal and/or fungicidal activity of chemical disinfectants used in food, industrial, domestic and institutional areas — Test method and requirements without mechanical action (Phase 2, Step 2)
IEC 60068-2-10, Environmental tests — Part 2-10: Tests — Test J and guidance: Mold growth
The testing involves exposing plastic test samples to the action of selected fungal and bacterial test strains (or, in the case of soil burial testing, microbially active soil) for specified or agreed periods of time.
duration under specified temperature and humidity conditions.
At the end of exposure, test samples are evaluated by visual inspection before and/or after cleaning and/or any changes in mass or other physical properties are determined.
Results obtained from samples exposed to microorganisms (test series I) are compared with results obtained from reference samples kept (test series 0) or sterile samples kept under the same conditions (test series S).
In the case of testing fungistatic properties, a visual assessment is made between test samples without biocide and samples containing biocide to demonstrate the effect of a biocide in a qualitative way.
Brief descriptions of the test methods used to determine the resistance of plastics to fungi (method A) or fungistatic effects (method B), resistance to bacteria (method C) and resistance to soil microorganisms (method D) are given in ISO 846 clauses 4.2 to 4.4.
Test samples are exposed to a mixed suspension of fungal spores in the presence of humidity ≥ 95% relative humidity. Once the limited nutrients from the spore itself are exhausted through the formation of a germination tube, the fungi can only grow at the expense of the material of the test samples. If the samples do not contain nutritional components, the fungi will not be able to develop mycelia and the plastic will not deteriorate.
Method A is suitable for evaluating the natural resistance of plastics to fungal attack in the absence of other organic substances.
Test samples are exposed to a mixed suspension of fungal spores in the presence of a complete nutrient medium, i.e. a carbon source. Even if the plastic does not contain any nutritional elements, fungi can grow on the samples and their metabolic products can attack the material by metabolizing the nutrient-agar medium.
Any growth inhibition on plastic or in nutrient-agar medium (inhibition zone) indicates fungistatic activity of the plastic or the presence of a fungicidal treatment.
To demonstrate the basic qualitative effect of a biocide in a plastic material, biocide-free samples should be included in the experiment. However, if these biocide-free samples show greater growth than biocide-containing samples, a qualitative indicator of fungistatic or fungicidal activity can be determined.
The effect of bacteria on test samples is evaluated using an incomplete medium without a carbon source1) . If there is no growth on the agar surrounding the sample, the sample does not contain any nutritional components.
If a material to be tested requires additional functionality, such as a product with hygienic effects, the plastic material to which a biocide has been added to impart antibacterial/hygienic properties to that material should be tested in accordance with ISO 22196, which provides guidance for measuring the basic antibacterial performance of non-porous (plastic) materials.
Test samples are completely buried in natural soil with a known water holding capacity and a certain moisture content.
Soil burial testing is included in this document because many plastics have been used in constant contact with soil and exposed to high humidity.
Selection of features for assessment of biodegradation
The choice of features to be determined depends on the purpose of the test. A visual assessment of biological attack should always be made as the first step in assessing the resistance of plastic.
It is recommended to determine properties that clearly indicate surface changes, such as surface gloss, flexural properties, impact strength and hardness.
Türkçe
English