Apart from their well-being, safety, and health, employees’ motivation and performance are also influenced decisively by the indoor climate. In view of this, organisations should seek to create optimal indoor climate conditions on both health and economic grounds. The indoor climate is characterised by the air temperature, air humidity, air velocity, and thermal radiation. This page discusses various tools and applications for workplace practice that can be used to measure and assess indoor climate parameters.

Assessment of Indoor Climate - Practical Guidance Document for Small and Medium-Sized Enterprises (DGUV Information 215-510)

Under DGUV Information 215-510 (previously BGI 7003), the indoor climate is assessed using a phased model. During the first phase (indoor climate observation), questionnaires are completed to identify the possible causes of complaints (e.g. general evaluation of the indoor climate, work situation, air-conditioning system). The indoor climate observation takes a qualitative approach involving measurements that can be carried out with relatively little effort. This phase puts the employer in a position to gather information about indoor climate conditions. The results from the survey then make it possible to determine:

• whether complaints about the climate can be dealt with by means of suitable technical or organisational measures or
• whether indoor climate measurements will be needed to evaluate the climate.

At the same time it is recommended that unfavourable scenarios also be taken into consideration where indoor climate conditions fluctuate (depending on the time of day and season).
It is expedient to apply the DGUV’s Climate Risk Graph - Workplaces under Thermal Stress (Risikograph Klima - wärmebelastete Arbeitsplätze) instrument specifically for workplaces affected by thermal stress, for example with air temperatures above 26°C and high levels of air humidity for extended periods of time. This makes it possible to use simple measurements of air temperature and relative air humidity to obtain more detailed information about the indoor climate situation without having to conduct a comprehensive indoor climate analysis.
If indoor climate observations have not supplied sufficient information in order to stipulate measures that will improve the climate situation, it is necessary to move on to the second phase, an indoor climate analysis. This is always the case if it is not readily apparent what has caused a difficult indoor climate situation, how it is to be evaluated, and how it could be improved. The indoor climate analysis is more extensive and has to be performed by experts, who may, for example, be occupational safety specialists, occupational physicians, or trained personnel from the social accident insurance providers.
The indoor climate observation and indoor climate analysis should allow the majority of indoor climate problems to be investigated and the situation in these workplaces improved by means of suitable measures. It is only necessary to go ahead with the third phase, an expert indoor climate report, if complaints continue to be made in spite of the measures taken and if the causes of impairments of well-being that are attributable to the indoor climate cannot be identified and rectified.

BAuA booklet regarding the risk assessment - manual for occupational health and safety experts

BAuA's booklet regarding the risk assessment includes information on preparing and implementing the risk assessment on the basis of the Occupational Health and Safety Act. The possible hazard factors are described in detail. In this, there is information on the type and the effect, thresholds, assessment criteria, and occupational health and safety measures for each hazard factor. Attached text modules may be used by occupational health and safety practitioners, e.g. in order to create checklists or for completing documentations. In another part, practical help (documentation templates, checklists, sources for ordinances and rules) are made available.
The section "Hazards due to working environment conditions" informs on the risk assessment, particularly when working under cold and heat. Initially, the effect of the climate on human beings is explained in a general part using climate variables, with the compensation limits for heat or cold stress being demonstrated as well. Then, a reference is made to the basic principles of climate determination. Regarding work performed in cold or hot conditions, possible types of hazards and their effects, as well as assessment criteria for a risk assessment are then demonstrated and suitable occupational health and safety measures for the respective situation are derived.
For example, cold stress may be reduced by increasing the room temperature and/or avoiding draught. Changing climate stress should be limited. In the event of unavoidable cold exposure times, personal protective equipment must be provided, recommended warming times must be complied with.
Heat stress may be avoided or reduced by taking technical measures, such as

• building design,
• airflow,
• thermal radiation protection,

or ergonomic-organisational measures, such as

• reduction of the work hardness,
• heat dissipation phases,
• acclimatisation,
• personal protective equipment,
• occupational healthcare.

The approach for performing room-climate measurements (e.g. measuring heights, measuring times, measuring sites, requirements regarding gauges, current thresholds and reference values of climate parameters) is described comprehensively in guideline LV 16.

Parameters for assessing room-climate parameters (LV 16 LASI)

In the publication LV 16 parameters for assessing room-climate parameters of the Commission for Occupational Safety and Safety Engineering of the Federal States (Länderausschuss für Arbeitsschutz und Sicherheitstechnik - LASI), the room-climate parameters air temperature, humidity, air velocity, and thermal radiation, as well as their measurement parameters are described. Based on the state of the art (standardisation), it is explained how measures must be performed (measuring heights, measuring times, measuring sites) in order to be able to determine and assess room air-related parameters. Regarding the measurement requirements, a differentiation is made between orienting measurements and increased requirements measurements. In analogy to the step model according to DGUV Information 215-510, you will also find questionnaires for assessing the room climate without using gauges (room climate observation) and checklists for orienting climate measurements (room climate analysis) here as well. The questionnaires and checklists, as well as suggestions for suitable measures may be used in a modified manner for proprietary climate evaluations.

Measuring instruments

There are various sensors, probes, and measuring instruments available with which indoor climate measurements can be taken. The measuring instruments selected will depend on the variables to be measured, the location where the measurements are to be taken, and the desired level of precision and have to be adjusted correctly for the measurement task in question. Apart from their regular calibration, it is just as important to think through carefully how measuring instruments are to be deployed on site if they are to be used correctly. Finally, quantitative results can only be analysed meaningfully if measurements are recorded with clear, comprehensive documentation. Annex 1 to the chapter on workplace climate in the Handbook on Risk Assessment (Handbuch Gefährdungsbeurteilung) includes an example of a measurement protocol for the documentation of a climate measurement. Extensive information about what is to be included in such documentation can also be found in publication LV 16 from the Committee of the Federal States on Occupational Safety and Safety Systems (Länderausschuss für Arbeitsschutz und Sicherheitstechnik, LASI).
The industry offers numerous instruments for indoor climate measurements. Economically priced measuring instruments are available on the market that, in addition to private settings, are also used in commercial environments, offices for example. These include simple measuring instruments that determine air temperature and humidity and are based on a range of measuring principles. Practical experience has shown that considerable deviations from target values are frequently found (+/- 2-3 K and +/- 10-15% relative humidity). Particularly if they have digital displays, high levels of precision are implied, which may lead to misjudgements and incorrect action being taken if these instruments are used.