Draft:Standard VDI 6032

• Comment: Wikipedia articles require independent secondary sources with in depth coverage of the subjects. These are not evident here. Secondary sources are needed, not those from the standards body.
  If decent sources are added to the article, feel free to ping my talk page once you've resubmitted the article for review. Stuartyeates (talk) 04:05, 3 November 2023 (UTC)

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An air filter that was replaced too late.

The standard VDI 6032 Hygiene requirements for ventilation and air-conditioning systems in vehicles of the Association of German Engineers (Verein Deutscher Ingenieure (VDI)) applies to air conditioning ventilation systems - also known as HVAC systems - and air treatment systems in vehicles for passenger transport. On its various parts, it describes the requirements for hygienic maintenance of the components, such as design, ventilation ducts, evaporators, the replacement of individual components, such as air filter, that become soiled and contaminated due to their regular use. Therefore these components need to be professionally replaced and cleaned, according to the current standard of the hygiene requirements of ventilation systems in train, bus, plane, truck, car and on ships. Air conditioning systems that are not cleaned regularly pose a health risk. Military vehicles are excluded. Since 2004, this policy has been updated and revised several times. This VDI standard is the recognized rule of technology. In the event of damage or incorrect cleaning, the experts assess liability to determine whether the current guideline 6032/2015 has been correctly complied with in full. VDI 6032 was issued and published in English and German in 2015 by the technical building services department of the VDI. Currently (since 2020) standard 6032 is being revised again according to the current state of the art by the VDI’s Vehicle Technology department.

VDI 6032 history

The 6032 standard for hygiene requirements is not new and was first published in German and English language in 2004 by the Association of German Engineers (VDI). Regular new findings and scientific evidence for the hygienic cleaning of ventilation systems, the air ducts adjacent to the pollen filter, the filter housing and the air conditioning evaporator have meant that this standard has had to be revised several times and has been expanded again and again. It is therefore considered state of the art in its current version.

In December 2022, the Association of German Engineers published the revised VDI standard 6032. The updated technical recommendations for the hygiene requirements for ventilation systems in cars and trucks were presented to the automotive industry as a green print draft. The appearance of this special publication indicates the start of a six-month period for objections from specialists.

The aim of the standard is to provide manufacturers, suppliers, fleet managers, employers and workshops with important technical recommendations in order to ensure state of the art indoor air hygiene or, quite simply, healthy air in cars and trucks.

VDI 6032 Part 1

This standard is about ventilation technology, air quality in vehicles and the hygiene requirements for ventilation technology. It regulates the hygienic maintenance process of HVAC and air conditioning systems in passenger vehicles.

"The standard VDI 6032 Part 1 provides guidance on hygiene in the design, installation and operation of ventilation systems in vehicles. Basic requirements are described for all vehicle types, and differentiated further for cars, busses, trucks, trains, ships and aircrafts. The accumulated experience in the air quality of buildings and the existing standard VDI 6032 was used for this standard.“

Scope

Since air conditioning systems affect the quality of the air from outside to inside, this standard is aimed at manufacturers, drivers and workshops that regularly come into contact with this component due to the maintenance intervals. All hygienic maintenance and repair measures that correspond to the state of the art are also defined. The general concept of hygiene is defined by measures that serve to prevent diseases and to maintain and strengthen health. "The system-specific contents of the hygiene checks and hygiene inspections shall be included to ensure sustained hygiene quality." This standard includes cars, lorries, buses, railway vehicles, planes and ships.

Hygiene requirements

When it comes to hygiene requirements of ventilation and air conditioning systems, the top priority is general safety. In addition to heat, their function is intended to convert, filter and transport away, coarse particles, odors and moisture (no fogged up windows), that the health of the driver and all passengers can be guaranteed. Even the slightest contamination due to the normal operation of an air conditioning system gradually deteriorates the air quality due to the very high air turnover (the air exchange rate in the vehicle). Accordingly, it becomes clear that there must be hygienic requirements in order to maintain the best possible state of the art for health. For this purpose, the use of cleaning agents and methods that are harmless to health is also defined. "Periodic maintenance, technical function checks and hygiene monitoring are of high importance.“ This is to ensure that there is no additional load and health hazards caused by the use of wrong cleaning agents and methods.

The requirements for maintenance and cleaning or replacement of parts and components of an air conditioning system apply to all vehicles to the same extent. They must be equipped with a suitable, custom-fit air filter – also known as a pollen filter. Installing or changing the filter must not leave any residues that are hazardous to health and must not be released during normal operation. The date of installation or replacement must be noted in order to be able to demonstrate the specified maintenance cycle in a verifiable manner. This applies to the digital storage and documentation of this data, too.

Car, lorry and bus specific requirements

Growth of mould, germs and bacteria between the fins of an uncleaned evaporator.

From the driver's point of view, the well-being of the occupants and passengers has top priority. However, air conditioning systems in automobiles, trucks and buses should also meet numerous requirements for road safety. "In all environmental and operating conditions, such as heat with solar radiation and humidity, extreme cold and precipitation, the ventilation system should contribute to increasing road safety." (For details, see EU Regulation No. 672/2010). In order to maintain this goal, a regular and very high exchange of air is necessary.

Growth of bacteria, mould and germs due to missed air filter change intervals.

Due to continuous operation, the components of air conditioning systems become contaminated. This can trigger allergies and sneezing attacks. A ventilation and AC system has to filter environmental influences from outside, such as pollen, bacteria, fine dust and other particles in the air, but it also has to deal with influences from the interior, such as hair, fur, vapors, dander and abrasion from seats. According to this, air conditioning systems are very dirty over time and must be regularly maintained and professionally cleaned. "Achieving a healthy supply-air quality requires that the AC system is cleaned - professionally - at regular intervals.“ The current VDI Standard 6032/2015 Part 1 describes that just replacing the pollen filter at regular intervals is not sufficient. The entire filter housing and the adjoining air ducts must be professionally cleaned to remove any stuck coarse particles and dust; as well as an effective cleaning of the air conditioning system evaporator at regular intervals (every 24 months), which consists of mechanical and chemical cleaning. This ist the only way ventilation systems can be hygienically cleaned and freed from any mold, germs and bacteria ensuring road safety and the health. The cleaning solutions in this procedure must be used by qualified personnel, meet the requirements of VDI 6032, must not alter any surfaces (roughening of PVC ducts, destroy coatings on the evaporators) or damage seals, for example, and must also be carefully documented for warranty reasons, so that liability can take effect in the event of damage.

Railway-specific requirements

This section of the guideline regulates the different requirements for ventilation systems in local and long-distance transport. The air distribution system consists of supply air and exhaust air ducts. A significant difference is, for example, that "..high-speed railway vehicles feature pressure protection units protecting the occupants against inadmissible changes in internal pressure.“

In addition, the various compartments are different in the case of railways. In areas with polluted air, such as the galley, toilet and washrooms, there must be a negative pressure compared to the passenger compartments. One important point does not differ, the hygienic requirement for air quality. This must also permanently comply with all requirements for the health protection of passengers and staff. "The initial hygiene inspection shall be conducted in the period between 12 and 48 months following commissioning as intended.“ Properly and comprehensibly documented, of course.

Ship-specific requirements

Air on water and sea can be assumed to be good, but this air contains water and salt, too. On the other hand in ports a ship is exposed to pollution, dust and odours. Accordingly, this standard also regulates air hygiene on ships. "In addition to dust-removing air filters, gas filters such as activated-carbon filters or other harmless mechanisms for separating gases shall be used where harmful gaseous contaminations occur." Due to the complexity, general checks are not sufficient enough here. However, depending on the component and location, these take place at 3/6/12/24-month intervals. "The specified hygiene checks aim at early detection and remedying of hygiene deficiencies in AC sys- tems through frequent visual inspection or microbiological random checks of the humidifier water.“ In addition to mere visual inspections, regular microbiological examinations must also be carried out on ships. Finally, each step is documented in a comprehensible and logical manner. This is the only way to be held liable in the event of damage.

Aircraft Specific Requirements

Air conditioning and ventilation systems in aircraft are known as environmental control systems (ECS), since they also perform significantly different tasks compared to the preceding vehicles. An aircraft moves in extreme temperature fluctuations and strongly changing pressure conditions. On the ground there is heat due to solar radiation and humidity, whereas at cruising altitude the air tends to be dry and below zero. In this way, “the ECS shall contribute to the flight crew’s sustained performance and ability to concentrate as well as support the passengers’ well- being.” For this purpose, the ECS tasks include a constantly maintained oxygen partial pressure, thermal comfort and the removal of material loads. These primarily serve to ensure the safety of the crew and passengers.

Hygiene checks take place as part of regular hygiene inspections in order to be able to identify and treat microbial infestation at an early stage, as well as to detect defects in components through visual inspections. Unlike motor vehicles, buses, trains and ships, all aircraft components are always disassembled for each inspection. A microbial examination alone is therefore not effective. All work steps, including disinfection measures and the condition of the individual components are properly documented and kept up to date on a daily basis.

Requirements for planning, production & execution

The hygienic planning of ventilation systems has a significant influence on healthy ambient and breathing air. Therefore developers, planners and designers must comply with basic design requirements. For example, the materials used in the area of the air-conducting surfaces must not emit any substances in concentrations that are hazardous to health. Of course, the materials must also not form any breeding grounds for microorganisms. With regard to the hygienic planning of ventilation systems, certain cleanliness values or a maximum level for contamination must be defined and continuously checked by automobile manufacturers, especially with the suppliers of the components. If the basic hygienic safeguarding of the components provided is neglected, it is pointless to design air conditioning systems and production technology that dirt deposits are avoided.

VDI / ZDK 6032 Part 2

Numerous cooperations support the updated standard. Probably the most important point of reference for changed standards in the automotive industry can be seen in the new designation of the technical regulation: VDI / ZDK Guideline 6032. The Central Association of the German Motor Trade (ZDK) recognizes the "Hygiene requirements for ventilation systems in cars and trucks" in equal measure and applies the state of the art to the automotive industry on an equal footing. For example the hygiene requirements of the VDI / ZDK standard 6032 become training and further education content for the German automotive trade. For the first time educational content pass through requirements of federal and state ministries and guilds.

Recommendation for the automotive industry

The Association of German Engineers accompanies the objection period of the updated VDI standard with a comprehensive publication. In particular, the causes of hygiene deficits in vehicle air conditioning systems described show, that recommendations for action are necessary for an industry whose only hygiene requirement is to change a cabin air filter after 24 or 36 months.

It is far too late to only think about your health when there is an unpleasant smell coming from the air conditioning in the car. In the approximately two-year revision period for the VDI standard 6032 there were important industry cooperations that share common hygiene goals for ventilation systems in cars and trucks  in addition to the adjustments to the recognized state of the art. An overview of the cooperation between the Federal Environment Agency and the Automotive Engineering Standards Committee can also be found in the VDI recommendation.

External links

• VDI recommendation for hygiene requirements for ventilation technology in vehicles