Climate chambers

The International Centre for Indoor Environment and Energy has at its disposal comprehensive facilities for conducting research on the effect of the indoor environment on human comfort, health and productivity. A wide range of thermal conditions and indoor air characteristics can be studied in the Centre’s three climate chambers, of which one is designed primarily for experiments on thermal comfort and two for experiments on human perception of air quality.

A "field-laboratory" has been established in an ordinary office space where effects of ventilation rate, air pollution, air humidity and the combined effects of thermal and acoustic environments on humans can be studied under conditions similar to those in real buildings. This setting minimizes the psychological effect of the artificial experimental situation on subject responses.

Two identical chambers or twin-chambers are used mainly for experiments on air quality, e.g. investigation of materials used in buildings or of HVAC components and systems. In order to minimize absorption of gases and particulates on walls and other surfaces, the chambers and their ductwork are made of stainless steel. With two identical adjacent chambers it is possible to study step changes of different environmental parameters. Subjects may walk from one chamber to the other with a different air quality, temperature, humidity or noise level, and express their immediate response to the change. The picture shows subjects waiting in one chamber prior to exposure to another environment in the adjacent chamber.

In the chambers, the impact on perceived air quality of different building materials is studied. The picture shows two master students preparing samples of floor material prior to an experiment. The samples are placed in glass cases with a well described, homogeneous airflow around the material. Air from the cases is presented to human subjects for assessment of perceived air quality in terms of acceptability, odour intensity, etc.

The largest of the Centre's climate chambers (5mx6m) is used mainly for experiments on thermal comfort. The chamber can be controlled within a very wide range of air temperatures and air humidities. In addition, independently conditioned air may be supplied locally to the chamber.
Human subjects are exposed to specific environmental conditions (air temperature, air humidity, etc.) in order to record their subjective and physiological responses to the exposure. Often, subjects are able to read or write during the experimental sessions

Three new climate chambers are being designed that combine the characteristics of traditional climate chambers, with controlled environmental conditions in a box-like room, and a visually realistic environment. The flexibility of the new climate chambers will allow different ventilation principles (mixing, displacement and piston flow), local supply of conditioned air near occupants and a very wide range of ventilation rates and pollution loads on the air to be studied for impacts on human comfort, health and productivity. A hall for studies of airflow in spaces is being renovated and three separate ventilation systems are installed, allowing flexible supply of ventilation air to the hall and to the experimental facilities.

In addition to laboratory studies of the indoor environment, comprehensive field studies with occupant surveys and measurement of air quality, ventilation and thermal conditions have been conducted.

Research comprises not only buildings. The indoor environment in cars, trains and other vehicles, e.g. cranes, have been studied extensively for air quality and thermal comfort conditions.

Measurement instruments

Thermal manikin
The Centre possesses a thermal manikin that is used widely in thermal comfort experiments. The manikin is divided into 16 individually controlled segments. The dry heat loss and surface temperatures can be recorded for each segment, for groups of segments or overall for the entire manikin.

Typically, the thermal manikin is used to measure heat loss under experimental conditions similar to those to which human subjects have been, or will be, exposed. The manikin is also used to measure the insulation of various types of clothing, sleeping bags and other products.

For evaluation of the transportation and distribution of pollutants around the human body, a breathing apparatus can be connected to the manikin. This mechanism enables studies of the interaction between breathing, convective airflows around the manikin caused by temperature differences between the surface of the manikin and the air, and the airflow in a space.

In a recent research project, measurements performed with thermal manikins from different European countries were made at the Centre. Comparison of measurements with different manikins was an important part of the project,  which resulted in a combined index for the evaluation of the thermal environment in vehicles.

Laser Doppler Anemometer

An advanced Laser Doppler Anemometer is used for the accurate measurement of low air velocities in spaces and for the investigation of the convective airflow around persons. By use of a computer-controlled traversing mechanism, measurements can be made in a precise matrix of points near the thermal manikin.

Gas monitor

Photoacoustic multigas monitoring equipment is used for tracer gas measurement of air change rates in spaces, for determination of the airflow in ventilation systems and for measurement of specific chemical compounds in the air. In addition, the Centre possesses an instrument for measurement of the ozone concentration in the air.

Instruments for thermal comfort measurements

Instruments for the measurement of parameters that are important for thermal sensation and comfort (air and radiant temperatures, air velocity and air humidity) as well as instruments for the direct measurement of integrated thermal indices that combine thermal parameters, clothing insulation and activity and express thermal sensation and comfort (PMV/PPD) are used in almost all studies. Furthermore, a thermal anemometer with (up to) 16 sensors is used for the measurement of airflow characteristics.