infrared thermography

The skin temperature and thermal comfort are closely related and change in skin temperature can predict thermal discomfort even before it is consciously perceived. The effect of changing thermal environment is most significant on the body extremities, particularly hands in cool and head in warm conditions. The skin temperature of the extremities can thus become a feasible control signal for personalized conditioning. In order to use a skin temperature of the extremities in practice as a control signal, it is necessary to measure it in a way that does not hinder a user.

There is a need to improve the accuracy of infrared thermography for measuring the temperature distribution of building exterior surfaces. Thermography is useful for building ventilation and thermal analysis, as well as understanding city ventilation and the urban heat island phenomenon. The key in correcting infrared images is to quantify accurately the reflected infrared contribution of surrounding surfaces as well as that of the atmosphere. Two new methods are proposed here for correcting measured temperature distribution of building exterior surfaces by infrared thermography.

Based on measured wall temperatures made by an infrared camera the flow and temperature fields were computed for an atrium. The nature of this atrium is a large enclosure inside a school building surrounded by halls and classrooms. Within a hybrid ventilation concept the stack effect during the summer time is used to form the main driving force for the night cooling of the classrooms. Time dependant computations were carried out to obtain the flow and temperature fields inside the atrium under various boundary conditions.

States that the introduction of focal plane array (FPA) products in infrared thermography in the 1990s dramatically improved quality and has helped to lower prices and that infrared thermography has long been used for building diagnostics because there is no better way to see otherwise invisible problems related to insulation performance or air leakage.

In this study the instantaneous temperatures and velocities close to a diffuser for displacement ventilation have been recorded by using whole-field measuring techniques. The air temperatures were measured indirectly by the use of a low thermal mass screen in conjunction with infrared thermography. The measuring screen was mounted parallel to the airflow, acting as a target screen. By using the thermal images the size of the near zone was also calculated. To determine air movements a whole field method called particle streak velocimetry (PSV) was used.