Testing | Checking | Measuring

Our test facility for determining the shaft sound level difference of ventilation systems provides a detailed analysis of multi-floor air ducting systems. In accordance with DIN 52210-6:2013, sound transmissions from ventilation ducts, exhaust air systems or individual components such as shaft branches can be measured. The test setup simulates realistic conditions with a variable duct system and separate duct branches for sending and receiving rooms. Strategically placed microphones at important points record the sound levels, delivering precise results to optimize ventilation systems. With a sound level difference of at least 55 dB (Dw), our test facility meets the highest standards for sound insulation analyses.

Testing and determination of the characteristics of chimney systems and their components in regard to thermal, moisture and flow behavior, corrosion resistance, thermal load capacity, gas tightness, construction and function. Determination of parameters relating to energy efficiency, fire resistance and environmental aspects and performance testing of individual and collective heating systems fired by solid and liquid (vaporizing burner) fuels.

Our two acoustic semi-anechoic chambers provide optimal conditions for conducting precise sound measurements. In the first chamber, specially designed for measuring sound power and directional characteristics, you benefit from an environment that is acoustically optimized to simulate the conditions of a free field. The second chamber is also temperature-resistant, making it particularly advantageous when it comes to measuring the noise generated by heat pumps and air-conditioning units. This adaptability makes it possible to test acoustic performance under different climatic conditions, ensuring realistic and practical results.

An environment with room acoustics optimized to reduce reflection is used to simulate the acoustic conditions of a free field above a reflecting plane. Such a room is classified as a semi-anechoic chamber. This environment can be used to perform highly accurate measurements of the radiated sound power from sound sources, as well as their directional characteristics. An acoustic free field is distinguished by the fact that the sound pressure level decreases proportionally with increasing distance from the sound source. This condition is achieved by lining walls and ceilings with special sound-absorbing materials, such as flat absorbers (industry) or wedge absorbers, as in this room. The chamber is about 20 meters long, which allows measurements of sound propagation over obstacles to be performed. Typical tasks include the measurement of sound diffraction or sound shielding via barriers, such as noise barriers, as well as the scattering or absorption of sound by acoustically relevant surfaces.

A few years ago, a test rig was developed at the Fraunhofer Institute for Building Physics IBP in Stuttgart for measuring the dynamic E modulus and loss factor based on ISO 6721-4 (non-resonant method). This method can be used to examine the E modulus and loss factor of foams and soft plastics (such as rubber, silicone, etc.) as a function of frequency.

Sound power is an important parameter for characterizing the noise emissions of machines, devices, and systems, as it quantifies the absolute power of a sound source regardless of its acoustic environment. A common method for determining sound power involves measurements under controlled conditions in the reverberation room, where the sound source operates within a diffuse sound field. The sound power is derived from the sound pressure measurements and corresponds to accuracy class 1. These measurements are carried out in third-octave bands according to DIN EN ISO 3741, covering an extended frequency range from 50 Hz to 10 kHz. Whether ventilation technology, HVAC technology, or other noise sources, the reverberation room facilitates detailed investigations using both direct and comparative methods. Its vibration-damped design and connection to an anechoic chamber provide additional flexibility to simulate a wide range of acoustic scenarios.

Our P3 diagonal test facility enables comprehensive analysis of the longitudinal sound insulation and joint insulation of a wide range of wall systems - from lightweight to solid constructions. Its innovative design, consisting of four adjacent rooms and elastic separating joints, allows for detailed simulation of real-world building and usage scenarios. This test bench meets the requirements of DIN EN ISO 10848-2 and DIN EN ISO 10848-3 standards, ensuring reliable, standard-compliant results. State-of-the-art measurement technology permits precise evaluation of airborne and structure-borne sound transmission in all relevant propagation directions, including direct, longitudinal, and diagonal transmission. These measurement results contribute significantly to optimizing the acoustic performance of your wall systems and meeting market requirements.

In our ceiling testing facility, flat roofs or lightweight ceilings can be installed according to DIN EN ISO 10140 (wooden ceilings). These include flat roofs, industrial roofs, wooden beam ceilings, solid wood ceilings and wood-concrete composite ceilings. The airborne and impact sound insulation of the ceilings, installation noise from bathtubs and shower trays, as well as the reduction of impact sound from screeds, hollow and raised floors, suspended sub-ceilings and much more can be measured effortlessly in the testing facility. The ceilings or roofs are installed on a circumferential bracket. The dimensions of the test object are approx. 4.78 x 3.78 m (L x B).

When raindrops fall on horizontal building elements such as roofs, skylights or window sills, they sometimes generate unwanted noise. This effect can cause noise pollution for building users or neighbors both outside and inside the building. Therefore, our scientists use our rain noise testing facility to measure the sound intensity level Li,A (sound power per 1 m² of roof area) that is generated when reproducible “standard rain” falls on sloping roof surfaces. These measurements are particularly relevant for roof constructions made of materials such as foil cushions, metal or sheet metal, as well as standing seam roofs and profiled roofs (ETFE).

Our suspended ceiling test facility (P5) enables the determination of the longitudinal sound insulation of suspended ceilings in accordance with the standard DIN EN ISO 10848-2:2018. With flexible configuration options, such as a ceiling that is infinitely height-adjustable, we offer optimum adaptation to individual testing requirements - without the need for structural modifications. A highly sound-insulating partition wall between the source and receiving rooms guarantees precise and reproducible measurement results. This technical setup provides ideal conditions for measuring closed suspended ceilings, grid ceilings and systems with integrated ceiling elements.

Our testing facility with solid installation walls can be used to precisely determine the noise generated by plumbing and water installations because a typical residential building is simulated. The testing facility consists of two rooms, one above the other, thus corresponding to a section of a typical residential building with two residential units above one other. Thanks to the way the rooms are arranged – bathroom above bathroom, each with adjoining living room – it is possible to measure the airborne and structure-borne sound generated by installations in one’s own and other people's living areas (requiring noise protection). In conjunction with the attic and basement floors, installations that extend over several floors, such as waste water systems (according to DIN EN 14366-1), drinking water systems or building service equipment, can also be tested.

In our specialized testing facility, we can determine the noise level Lap in accordance with DIN EN ISO 3822. The noise generated by sanitary taps, fittings, valves and other water installation devices is recorded in detail, transmitted via a standardized measuring setup in our measuring lab and then compared with the noise level generated by the installation noise standard (IGN).

At the Fraunhofer IBP screed test stand, the impact sound reduction and airborne sound insulation of ceilings, ceiling coverings, and suspended ceilings, on a solid reference ceiling are examined according to DIN EN ISO 10140. The standardized 140-mm-thick reinforced concrete test ceiling separates two adjacent reverberation rooms, providing optimal conditions for acoustic analyses. Flanking transmission is minimized by additional lining, while the standardized tapping machine and alternative impact sound sources, such as fitness weights or rubber balls, are used for impact noise measurements. The test stand is suitable for floating screeds, cavity floors, raised floors, and various floor coverings. In addition to impact sound measurements, structure-borne sound and modal analyses can also be performed.

In our installation testing facility, the noise from sanitary and water installations can be precisely determined using lightweight dry construction installation walls. The testing facility consists of two rooms, one above the other, which can each be subdivided into a total of four rooms by a (lightweight) installation wall. It thus corresponds to a section of a typical residential building with two residential units above each other with lightweight installation walls. Thanks to the way the rooms are arranged – bathroom above bathroom, each with adjoining living room – it is possible to measure the airborne and structure-borne sound generated by installations in one’s own and other people's living areas (requiring noise protection). In conjunction with the roof and drainage system under the testing facility, installations that extend over several floors, such as waste water systems (according to DIN EN 14366-1), drinking water systems or building service equipment, can also be tested.

At Fraunhofer IBP, sound insulation tests for raised and hollow floors are conducted using various test facilities, including the wall and ceiling test stand, all of which meet the requirements of the DIN EN ISO 10140-5:2021 standard. The flooring system to be examined is installed directly onto the concrete floor of the test stand. A highly sound-insulating partition wall extends from the ceiling to just above the surface of the raised floor between the source and receiving rooms. This partition wall is fitted with mineral wool and a permanently plastic seal to minimize flanking transmission. Measurements are carried out using dodecahedron loudspeakers, standard tapping machines, and rotating microphones. The system’s flexibility allows for the testing of various floor systems, including those with air outlets or floor bulkheads.

In the Fraunhofer IBP reverberation chamber, the sound absorption coefficient of sound absorbers, acoustic panels, noise barriers, and suspended ceilings can be determined. Similarly, the equivalent sound absorption area of items such as mobile partition walls, seatings and other individual objects can be determined. The measurements are carried out according to DIN EN ISO 354 with diffuse sound incidence. Due to its size and construction, the reverberation chamber also offers the possibility to carry out measurements in the low-frequency range. A unique feature of the reverberation chamber is its sliding door, which allows for sound absorption measurements to be carried out under both diffuse sound incidence and free-field conditions. This flexibility makes it possible to simulate a wide range of realistic acoustic scenarios. Additionally, the reverberation chamber is equipped with a vibration-damped structure that minimizes structure-borne sound transmission, ensuring highly accurate measurement results.

The P2 wall test stand at Fraunhofer IBP is specifically designed to determine the sound insulation of wall constructions in accordance with DIN EN ISO 10140-2. Equipped with two surrounding joints to effectively suppress flanking transmissions, it enables reliable testing of highly sound-insulating building components, such as cinema partition walls or installation walls. The test stand allows wall constructions to be mounted up to the bare ceiling or below a lintel with integrated Halfen channels. Its large test opening and drivable equipment provide maximum flexibility for analyzing solid and lightweight walls, mobile partition walls, and facade elements. A standout feature of the P2 test stand is its ability to precisely evaluate sound insulation at low frequencies – a crucial factor for achieving acoustic excellence.

At the Fraunhofer IBP door test facility, the airborne sound insulation of doors, door leaves, and panels is measured in accordance with DIN EN ISO 10140-1 to 5. Two soundproof reverberation chambers, separated by a highly sound-insulating wall with a standardized test opening, enable the evaluation of acoustic properties. The use of cladding effectively suppresses flanking transmission within the rooms. The test facility also offers flexibility for testing a wide range of components, including partition wall sections and additional cladding. With the help of state-of-the-art measurement technology, reliable and standard-compliant data for acoustic optimization can be generated.

In addition to windows, we use our window testing facility to test the acoustics of glazing, façade or wall sections, roller shutter boxes, panels, ventilation elements, joint seals and small-size components. The tests are carried out in accordance with DIN EN ISO 10140-5 with a clear opening of 1.25 m x 1.5 mm (test area: 1.875 m²). For components with smaller dimensions, the test opening can be adapted accordingly with the aid of a multi-shell, highly sound-insulating construction. A crane is available in the testing facility for installing and removing heavy components.

The facade test facility P1 at Fraunhofer IBP meets the requirements of DIN EN ISO 10140-5:2021. The test stand is vibration-isolated, with a surrounding joint effectively suppressing flanking transmission between the source and receiving rooms. Its versatile test opening allows for the measurement of facade elements, windows and sliding doors, as well as complex mock-up facades with installations. Cutting-edge state-of-the-art measurement technology ensures precise assessment of sound insulation under realistic conditions, including dodecahedron loudspeakers in the test rooms and circularly moving microphones in the receiving room. The test stand is designed to accommodate even large facade elements, which can be delivered and installed using a truck-mounted crane. This makes it ideal for innovative development projects and quality assurance of a wide range of building components.

Dynamic stiffness is a key indicator of the effectiveness of sound insulation underlays and of the reduction of impact sound in flooring systems. To determine this property precisely, our experts carry out measurements in accordance with the DIN EN 29052-1 standard. This test method determines the resonant frequency of the vertical fundamental vibration of a system consisting of the insulating material to be tested and a panel placed on top of it, which is excited by sinusoidal signals.

The P6 wall test stand at Fraunhofer IBP provides the ideal platform for determining the sound insulation of a wide range of wall constructions, including glass partitions, noise barriers and mobile walls. Measurements are carried out in accordance with DIN EN ISO 10140-2, using cladding shells that reliably suppress flanking transmission. The flexible test opening and integrated Halfen channels enable quick assembly and easy adaptation to specific requirements. Whether for cinemas, offices, or other applications, the test stand delivers results that enable profound acoustic optimization. Equipped with state-of-the-art technology and accessible infrastructure, the P6 test stand is designed for complex projects and innovative construction solutions.

The ceiling test stand at Fraunhofer IBP is specifically designed to measure airborne and impact sound insulation, as well as the impact sound reduction of timber structures such as timber beam ceilings, solid wood ceilings, and lightweight ceilings. With two adjacent reverberation rooms, separated by a variable ceiling support, the test stand enables analysis according to DIN EN ISO 10140. Flanking transmissions are minimized by additional linings, while standardized tapping machines and alternative impact sound sources, such as fitness weights or Japanese rubber balls, are used for measurements. The test stand is ideal for use in residential buildings, for industrial roofs, and innovative construction projects. In addition to low-frequency impact sound, walking noise and structure-borne sound can also be analyzed to ensure comprehensive acoustic optimization.

Laser scanning vibrometry enables non-contact vibration analysis for a wide variety of objects. Using a customizable measurement grid and automatic scanning, the system captures detailed vibration data, making vibration patterns visible and rendering them as videos. With a frequency range of up to 40 kHz and a broad measurement spectrum, the technique meets even the most complex requirements. It is suitable for analyzing machines, devices, tools, and components, accomodating both structure-borne and airborne sound excitations. With the ability to export data for modal analysis or simulation into external programs makes laser scanning vibrometry a flexible and powerful solution for optimizing vibration behavior and noise emissions.

The PK combined test stand at Fraunhofer IBP is specifically designed to determine the sound insulation performance of room-height components such as doors, windows, window facades, and large-scale partition walls. The test stand meets the requirements of the standard DIN EN ISO 10140-5:2021. Spatial and temporal averaging of sound pressure levels is achieved by means of a pneumatically moved dodecahedron loudspeaker and rotating microphones, enabling highly precise measurements under realistic conditions. To suppress flanking transmissions, a circumferential joint separates the source and receiving rooms. The combined test bench is not only suitable for conventional building components, but also for specialized applications in automotive, aerospace, and marine industries.

The building acoustics test laboratory is recognized by the German Institute for Building Technology (DIBt) as an approved Group I testing center authorized to carry out the full range of performance and quality tests according to DIN 4109.

In order to study and further develop innovative supply concepts for residential buildings, heating systems (with/without solar thermal or photovoltaic panels), their storage units, ventilation systems and control concepts under realistic conditions prior to practical use, Fraunhofer IBP has twin houses on its field test site.

In the hearing threshold laboratory, we conduct precise hearing threshold measurements and hearing tests. This purpose-built laboratory is designed to conduct measurements near the threshold of hearing and to perform comprehensive sound evaluations. The laboratory creates optimal conditions for subject tests in order to accurately evaluate building-physical sounds, product sounds or environmental sounds via headphones. The special design minimizes interference from external noise, ensuring precise and reliable psychoacoustic measurements.

The semi-anechoic chamber with all-wheel drive chassis dynamometer at Fraunhofer IBP provides a state-of-the-art environment for conducting detailed acoustic tests on vehicles. This testing facility makes it possible to realistically simulate driving conditions for cars, vans and motorcycles in order to accurately measure both interior and exterior noise. Among other tests, we use the facility to carry out simulated pass-by noise tests according to ISO 362-3 and UN-ECE R51, in which the exterior noise is measured at a defined distance. In addition to a Safety-Walk™ surface, rough asphalt surface elements or impact bars can be installed. Thanks to a versatile pallet changing system, vehicles can be efficiently prepared for decoupling studies, for example, or to mount sensors. The facility also boasts a fully-equipped workshop with lifting platforms, tire fitting and wheel balancing stations, as well as a fast-charging station for electric vehicles.

The acoustic camera uses an array of microphones to precisely localize sound sources. The sounds emitted by a source are recorded by several microphones. The differences in the time of arrival of the incoming sounds (phase position) can be used to draw conclusions about their location and intensity. A color noise map created from these signals is optically superimposed on the photo or video of the object under investigation.