Reflections on the state of research: indoor environmental quality.

UNLABELLED: More than 30 years after the First International Indoor Climate Symposium, ten researchers from the USA, Slovakia, Sweden, and Denmark gathered to review the current status of indoor environmental research. We initiated our review with discussions during the 1-day meeting and followed that with parallel research and writing efforts culminating with internal review and revision cycles. In this paper, we present our choices for the most important research findings on indoor environmental quality from the past three decades followed by a discussion of the most important research questions in our field today. We then continue with a discussion on whether there are research areas for which we can 'close the book' and say that we already know what is needed. Finally, we discuss whether we can maintain our identity in the future or it is time to team up with new partners. PRACTICAL IMPLICATIONS: In the early years of this field, the accumulated knowledge was small and it was possible for any researcher to acquire a complete understanding. To do so has become impossible today as what we know has grown to exceed the learning capacity of any person. These circumstances challenge us to work collectively to synthesize what we do know and to define clearly what remains to be learned. If we fail to do these things well, we risk repeating research without memory, an inefficiency that we cannot afford.

International standards and the ergonomics of the thermal environment.

The main purpose for heating and air conditioning of workspaces is to provide an environment that is acceptable and does not impair the health and performance of the occupants. Owing to production processes and external climate it may be necessary to work in unacceptable conditions for limited time periods. However, it must be ensured that these conditions do not impair the health of the employees. To do that, standard methods are needed so that different solutions and evaluations of the thermal environment can be done in a comparable way. The standards presented in the present paper include evaluation methods for moderate, hot, and cold environments, supporting standards for measuring and determination of the relevant parameters, and standards for measurement and evaluation of individual physiological conditions of humans.

Standards for moderate thermal environments.

Recently two Draft International Standards dealing with specifications of the conditions for thermal comfort (ISO DIS 7730) and measurement procedures (ISO DIS 7726) have been approved by the International Stadardisation Organisation (ISO). The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) has made a standard with similar requirements for the thermal environment (ASHRAE, 1981). To verify the requirements, measurements of different thermal parameters have to be performed. Guidelines as to how and where to measure are also given in the standards. The present paper deals mainly with the requirements and measurements that are relevant for moderate thermal environments in places of residence, offices, hospitals and light industry. For evaluation of very hot or very cold surroundings, other methods are required. Only measurements of parameters that influence the perception of the thermal surroundings are included.

The influence of local effects on thermal sensation under non-uniform environmental conditions--gender differences in thermophysiology, thermal comfort and productivity during convective and radiant cooling.

Applying high temperature cooling concepts, i.e. high temperature cooling (T(supply) is 16-20°C) HVAC systems, in the built environment allows the reduction in the use of (high quality) energy. However, application of high temperature cooling systems can result in whole body and local discomfort of the occupants. Non-uniform thermal conditions, which may occur due to application of high temperature cooling systems, can be responsible for discomfort. Contradictions in literature exist regarding the validity of the often used predicted mean vote (PMV) index for both genders, and the index is not intended for evaluating the discomfort due to non-uniform environmental conditions. In some cases, however, combinations of local and general discomfort factors, for example draught under warm conditions, may not be uncomfortable. The objective of this study was to investigate gender differences in thermophysiology, thermal comfort and productivity in response to thermal non-uniform environmental conditions. Twenty healthy subjects (10 males and 10 females, age 20-29 years) were exposed to two different experimental conditions: a convective cooling situation (CC) and a radiant cooling situation (RC). During the experiments physiological responses, thermal comfort and productivity were measured. The results show that under both experimental conditions the actual mean thermal sensation votes significantly differ from the PMV-index; the subjects are feeling colder than predicted. Furthermore, the females are more uncomfortable and dissatisfied compared to the males. For females, the local sensations and skin temperatures of the extremities have a significant influence on whole body thermal sensation and are therefore important to consider under non-uniform environmental conditions.

International standards for the indoor environment.

UNLABELLED: On the international level, International Organization for Standardization (ISO), European Committee for Standardization (CEN) and American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) are writing and reviewing standards relating to the indoor environment on a regular basis. This presentation will focus on the development of standards for the indoor thermal environment and indoor air quality (ventilation). In the future, recommendations for acceptable indoor environments will be specified as classes. This allows for national differences in the requirements as well as for designing buildings for different quality levels. Several of these standards have been developed mainly by experts from Europe, North America and Japan. Are there, however, special considerations relating to South-East Asia (lifestyle, outdoor climate, economy) that are not dealt with in these standards and that will require the revision of existing standards? Critical issues are: adaptation, the effect of increased air velocity, humidity, type of indoor pollutant sources, etc. This paper will present an overview of existing methods, and discuss areas where revision of present standards or the development of new standards, are needed. PRACTICAL IMPLICATIONS: The international standards for the indoor environment provide the designer with criteria, which are internationally recognized, for the design of buildings and systems.