We create perfect conditions to preserve cultural treasures.

Climate control and air quality.

A central task of preventive conservation is to influence the environmental conditions in which a cultural object or collection is located in order to slow or prevent natural and accidental deterioration of objects.

The local climate and air quality are among the most important factors influencing the conservation of materials.  For this reason, two main measures are taken: structural measures to keep the indoor climate of a building as stable as possible, and climate-controlled display cases to create a stable microenvironment specific to the collection.

Depending on the nature of the collection, the relative humidity, temperature and air quality in the display cases are adjusted and maintained.

RH Stabilization

Glasbau Hahn uses two methods to control and maintain the relative humidity: the passive method using hygroscopic material and the active method using constant humidity equipment or a combination of the two. We can advise you on the advantages and disadvantages of each method.

In addition to controlling relative humidity, one of the most important aspects of display case climate control is avoiding short-term fluctuations in relative humidity that can cause materials to crack. Active systems are more versatile, more responsive and can handle large volumes where passive systems are limited.


Temperature affects the volume of air as it expands and contracts, changing its ability to hold moisture. It therefore affects the relative humidity, which is a key factor in the wellbeing of the materials in the collection. Metals, for example, need dry air to slow corrosion, while organic materials need more humid air to prevent them drying out and becoming brittle.

Temperature affects the rate of reaction in chemical processes. Therefore, best practice now recommends a temperature range of 19 °C to 21 °C, which corresponds to the typical room climate and therefore does not require additional temperature control. Only in individual cases will the room climate require different temperatures. For such cases, Glasbau Hahn offers the T-300 temperature module or the service to develop customized solutions.

Air filtering

The third factor is air quality, which is controlled and, if necessary, improved by filter systems and/or absorber materials. Our filter machine can also kill germs and bacteria. For this purpose, our APU3 filter unit is used or filters are already integrated in our constant humidity units.

Modified Air System

Glasbau Hahn offers special display cases with modified air, e.g. the so-called nitrogen showcases. For details, please contact directly our climate control department.

All methods of creating microclimates should be complemented by an additional independent control system, which should include data loggers for temperature, relative humidity, lux and VOC levels of the air.

Below is a brief introduction to our equipment:


The RK-2/5 offers freely selectable air humidity between 35 % and 75 % via germ-free clean air for room volumes up to 5 m³.

  • The unit’s low profile, 150 mm, of makes it ideal for placement directly inside the showcases technical compartment
  • Best suited for showcases with individual relative humidity setting
  • Water level has to be checked and adjusted manually
  • Can optionally be fitted to reduce pollutants inside a showcase
  • Can optionally be coupled with a mobile nitrogen generator, building an oxygen free environment inside the showcase, thus strongly reducing bacteria and corrosion
  • Requires yearly maintenance


The RK-2-xa/5 offers freely selectable humidity between 35 % and 75 % via germ-free clean air for up to 20 showcases with a total volume of up to 50 m³.

  • Optionally, the RK-2-xa/5 can be fitted with an extension module, which allows it to condition up to 100 m³, or up to 40 showcases with the same humidity setting.
  • Supports airflow regulation for each output, making it the best choice for multiple showcases of different size and volume.
  • Can optionally be fitted with automated drainage and purified water supply
  • Can optionally be coupled with a nitrogen generator, building an oxygen free environment inside the showcase, thus strongly reducing bacteria and corrosion
  • Best suited for installing in a separate technical area
  • Requires yearly maintenance


The Air Purifying Unit 3/3+ is designed for pollutant and bacteria reduction inside of art envelopes with a volume of up to 3 m³

  • Seamless setup via the Glasbau Hahn Remote App
  • Multiple function parameters can be set, such as always on, timetable with weekly schedule function, or using a VOC- index measured by the sensor placed inside the art envelope (only APU 3+)
  • The APU 3+ also includes data logging for RH, Temp. and VOC-index, with settable recording intervals.
  • Can optionally be extended with slave devices for an increased filtration capacity for larger showcase volumes
  • Logged data by the APU 3+ also can be exported in multiple formats and used for evaluations of the air condition inside a showcase
  • Very low power consumption (approx. 12 Wh)
  • Requires yearly maintenance

T-300 (Temperature unit)

The T-300 is designed to stabilize temperature fluctuations inside a single showcase with up to 1 m³ volume.

  • It can operate independently from other climate control units, thanks to a separate control module
  • Offers stable temperature adjustment of up to +/- 5 °C from ambient temperature
  • Cooling – liquid free construction
  • Can be coupled with stable relative humidity or filtration devices
  • Maintenance free

(Protector-Sensor 2023)

  • The protector showcase for paintings offers a stable environment, with stable relative humidity and pressure levels.
  • The integrated sensor can be controlled via the Glasbau Hahn Remote app completely wireless, and offers current measurements and data logging, strongly reducing the need for regular humidity level checking.
  • The sensor offers storing capacity of up to one year and runs in loop, so that recording will never be stopped
  • The sensor can optionally be fitted with a LUX sensor which is flexibly placed inside the Protector case, capable of recording LUX levels of up to 65.000 lx
  • Sensor maintenance – batteries as needed, depending on recording settings and download frequency.

Hahn Smart Silica
(The smart silica compartment)

  • The Glasbau Hahn Smart Silica converts conventional silica gel containers into active smart desiccant recipients.
  • Active air movement and integrated data logging are some of the key aspects of the Smart Silica.
  • Controlling of the Hahn Smart Silica is achieved wirelessly and without opening the showcase base, via the Glasbau Hahn Remote app.
  • The demand-controlled air movement is regulated by a sensor inside the display case with adjustable parameters and aims to reduce the time it takes to reach the desired conditions again after the display case has been opened or after strong fluctuations due to the ambient conditions.
  • By logging the internal condition of the display case, it becomes easier to estimate the schedule for replacing the silica gel.
  • Maintenance free, other than the reconditioning of the desiccant

Glasbau Hahn APP.

The Glasbau Hahn APP is designed to serve as the communication hub for a new generation of devices that are equipped with a variety of different sensors.

For detailed information, planning support and data sheets please contact our climate control department.

Do you wish more information?

Write us a message or call us directly at

+49 (0) 69 94417-60

Let us advise you!