Knauf Knauf

Acoustics planning in healthcare facilities


7 tips you should know for planning ceiling solutions in healthcare facilities

Where many people come together in a comparatively small space, where intensive communication and care takes place around the clock, supported by devices, machines and a complex technical infrastructure - it can hardly be silent. Effective room acoustics meeting the applicable requirements are therefore indispensable in healthcare facilities. Solutions cannot come off the shelf, but have to be individually planned and implemented. The following seven tips explain important details for this process and provide valuable advice.

Noise has a major impact and a wide range of effects in healthcare facilities

In a research project on the topic of "Noise in hospitals", researchers at the Bauhaus University in Weimar found that both patients and staff can be affected by noise-related stress. For the employees this means a strong impairment in intellectual activities, while in the case of patients the recovery process can be negatively influenced, which in turn leads to longer hospital stays.

When planning hospitals, hygiene and room acoustic requirements must both be met, in varying degrees from the entrance area to intensive care units. Harmonising the requirements is a great challenge. Infection control, hygiene and washability are obvious standards in hospitals that can be achieved primarily through the use of smooth materials and reverberant surfaces. However, these generate reverberation effects that make the room appear loud and are therefore annoying for patients and staff.

Through careful design and forward planning of the rooms, acoustically sensitive areas can be separated from acoustically unproblematic areas, e.g. by zoning. Special ceiling and wall elements meet both hygienic and room acoustic requirements.

Healthcare facilities require customised room acoustics

The German standard DIN 18041 "Acoustic quality in rooms - requirements, recommendations and instructions" provides good guidance for room acoustics.

Rooms in health facilities are classified in room group B (audibility over a short distance) in accordance with DIN 18041; depending on the type of room, the classifications are divided between room groups B2 to B5. For almost all types of rooms in healthcare facilities, room acoustics measures are stated according to DIN 18041.

The necessary measures should achieve a reduction of the mean noise level in the room, dependent on use, and limit reverberation. In general, the necessary measures (given below for a room height of 2.5 m) are based on the length of stay and the level of comfort.

The following areas from health facilities are classified in room groups B2 to B5:

  • RG (room group) B2: Rooms for short-term stay (including entrance halls, reception areas with waiting areas) – A/V ≥ 0.15
  • RG B3: Rooms for long-term stay (including patient rooms and treatment rooms) – A/V ≥ 0.20
  • RG B4: Workrooms (including reception and counter areas, laboratories, resident rooms in care facilities, single and multi-person offices) – A/V ≥ 0.25
  • RG B5: Rooms with special requirements for noise reduction and room comfort (including canteens, industrial kitchens and exercise rooms) – A/V ≥ 0.30

To describe the room acoustic conditions, the so-called A/V ratio is used as an orientation value, i.e. a minimum of necessary absorbing surfaces in relation to the room volume V, technically speaking the equivalent sound absorption surface A. Compared to rooms with short-term stay times (RG B2, A / V ≥ 0.15), double the amount of acoustically effective area must be occupied for special room comfort requirements (RG B5, A / V ≥ 0.30). People in the room are not taken into account.

Ceiling systems in clean rooms must comply with hygiene standards and regulations

A clean room is a room in which the concentration of airborne particles is kept as low as necessary. Clean rooms are indispensable in medical research, treatment and the sterile production of pharmaceuticals. The need to have such rooms is made clear by the corona pandemic in all its dimensions. They allow various parameters such as the number of particles, number of germs, temperature, humidity and pressure to be precisely monitored and set. This ensures that the existing and incoming air is extremely pure and meets all the required cleanliness criteria. This helps protect patients and ensure the quality of medical products.

In these rooms, materials for acoustic ceilings or their surfaces must be compatible with the standards and regulations for hygiene and classified according to the precise areas of application.

The air purity classification according to ISO 14644-1 is the best-known standard in the field of clean room technology. It specifies the maximum number of particles in the ambient air and divides the clean rooms into classes from ISO 1 to ISO 9, with class 1 making the highest demands on purity (see picture 2 - table Air Purity Classification).

Laminar air flow is characteristic of the classification in air purity classes 1 to 5. No turbulence forms here and the flow pattern is uniform. With a turbulent flow (air cleanliness classes 6 to 9), eddies are created and the flow pattern behaves unevenly.

It should be noted that clean rooms of classes 1 to 5 according to ISO 14644-1 have a high presence of filters and the use of closed ceiling elements is sometimes not possible. Clean rooms with horizontal displacement flow are an exception.

The NFS standard offers a very good national and international orientation

Acoustic ceilings and wall absorbers should meet the criteria of the French (internationally applicable) standard NF S 90-351:2013. This standard defines the safety requirements for the design, construction, operation, maintenance and usage methods of systems for air cleaning and air control in healthcare facilities.

The standard divides the various areas of application into four risk zones.

  • Zone 1 (Area A) low risk: offices, entrance areas, corridors
  • Zone 2 (Area B) medium risk: examination + patient rooms, sanitary + kitchen areas
  • Zone 3 (Area C) high risk: examination rooms, laboratories, intensive care units
  • Zone 4 (area D) very high risk: operating theatres, clean rooms

The four zones are each assigned to clean room classes, decontamination classes and bacteriological cleanliness classes (see picture 2 - table Purity Classes according to NF S 90-351:2013).

Knauf AMF has a wide range of ceiling systems that have been tested and approved for the highest demands according to NF S 90-351.

A microbiological classification is necessary

The details for this area are also specified in the French standard NF S 90-351:2013. The effect of the ceiling and wall material on the reduction of pathogens (bacteria, fungi, yeast) is evaluated.

As part of the test, the surface is contaminated with certain microorganisms over a period of 3 to 7 days (depending on the bacterial strain used) and the reduction in germs on the surface and in the room air is assessed. This results in the classification into bacteriological purity classes. M1 represents the best possible class. Further classes are M10 and M100.

The ceiling tiles should at least prevent pathogens from growing there; active control and rapid reduction of the microorganisms is even better.

Knauf AMF uses the Hygena colour coating for this purpose. This has a preventive effect against the following microorganisms / pathogens:

  • Escherichia Coli,
  • Aspergillus Niger,
  • MRSA (multi-resistant Staphylococcus aureus),
  • Candida Albicans,
  • Pseudomonas aeruginosa,
  • Proteus mirabilis,
  • Clostrum difficile

The effectiveness of the hygienic paint coating has been tested according to the following standards: EN ISO 846: 1997, ASTM G21-15, ISO 22196: 2011, JIS Z 2801, NF S 90-351

The Knauf AMF ceiling systems relevant for this area are all M1 - classified.

Cleaning, disinfection and humidity resistance of the surfaces are relevant

The surfaces of the ceiling elements in healthcare facilities must be cleaned or disinfected regularly, taking hygiene aspects into account, depending on the area of application.

The materials on the visible side of the tiles must be able to withstand these processes without restricting their specific properties. In principal, it is recommended to consult a hygienist when choosing the material for the ceilings in healthcare facilities.


It is important to use only the right cleaning method with the appropriate cleaning agents for each face coating of the ceiling tiles.

The following types of cleaning are possible:

Dry cleaning
A normal vacuum cleaner should be used as the standard cleaning method for dust, loose dirt and / or deposits, provided it has a soft brush.

Damp cleaning
The surfaces can be cleaned with a damp cloth for more intensive cleaning. This must always be done with a squeezed out, soft cloth or sponge. After cleaning, the surface must be dried with a soft cloth.

Wet cleaning
Wet cleaning must be carried out with lukewarm water (up to 40 ° C) using a sponge and in combination with a mild cleaning agent (pH value between 7 and 9). Make sure that the edges and the back of the tiles do not come into contact with moisture. After cleaning, the surfaces must be dried.

Pressure cleaning
Pressure cleaning must only be carried out for ceilings with an exposed, pressure-resistant construction (Exposed System - System C, edge SK) under the following technical requirements:

  • Water temperature: max. 40 °
  • Working pressure: max. 80 bar, the delivery rate may be max. 500 l / h
  • Spray angle (nozzle): at least 30 °
  • Minimum distance: 1.0 m (nozzle - surface)

With cleaning methods 2 to 4, it is essential to prevent moisture from penetrating into the substructure. Before cleaning the ceiling surface, it is worth carrying out a test on a non-visible tile or on a test piece in order to assess the effect and to rule out any interactions with the coating. Abrasives are generally not suitable.

Knauf AMF provides an overview table with the most suitable cleaning method for each ceiling tile surface ( Healthcare Brochure - page 15).

Disinfectant resistance

In certain areas of application, hygiene regulations require the face side of the ceiling tiles to be disinfected. Therefore, when selecting the material, make sure that the surfaces are resistant to disinfectants.

The determination of the material compatibility when using disinfectants is carried out according to EN ISO 2812-3: 2012 and EN 12720: 2013. The tests simulate exposure over 3, 9 and 15 years. The evaluation is carried out in grades from 5 (no change in the test areas) to 1 (major change).

Knauf AMF has proven the disinfection resistance of the relevant ceiling tiles. The systems and the respective suitable disinfectants are clearly shown in a table ( Healthcare Brochure - page 13).

Humidity and corrosion resistance

The air humidity has a significant influence on the stability and structure of a mineral ceiling and thus its durability. In many cases, high water vapour content leads to loss of dimensional stability and deformation. Air behaves like a sponge and, depending on the temperature, can absorb water in the form of steam. In addition to the resistance of the tiles to high humidity, the substructure in such areas should be made corrosion-resistant. EN 13964: 2014 "Suspended ceilings - requirements and test methods" specifies exposure classes.

Professional support from (external) hygiene advisors is useful

Qualified hygiene experts should be involved in the planning and implementation of room acoustic measures in healthcare facilities. The specialists can have acquired the necessary know-how through in-house training measures, or they are hired by the health facilities as external service providers. As specialists, they know the respective requirements and applicable regulations for hygiene and infection prevention and later also check their implementation during ongoing operations.

Thanks to early collaboration and ongoing intensive exchange between those responsible for planning, the hygiene specialists and the room acoustic experts, a professional ceiling solution can be achieved for all relevant areas that meets the requirements of the highest hygiene standards and appropriate room acoustics.

Fill in the form and download the white paper „7 tips for planning ceiling solutions for healthcare facilities“!