User Perception of Climate in Hospital Wards. An Analysis of Thermal Climate and Air Humidity Demands.

Doktorsavhandling, 2007

There are very few studies on perceived climate in hospital environments. This study deals with hospital wards, the consequences of establishing requirements for air humidity in them, and the use of existing recommendations and guiding principles. Many variables affect people’s perception of the indoor environment. The physical environmental variables are relatively easy to measure. The difficulty lies in linking the measured values to medical consequences and effects. A way to do this is, as in this study, to combine objective measurements and questionnaires. The thesis work combines a literature survey and a measurement program. The survey concentrates on indoor climate and its medical aspects; it also indicates the importance of air humidity from both climate and medical points of view. In practice, this type of information seems to have disappeared in the design process. The field studies were carried out in four selected Swedish hospitals during both summer and winter. Objective measurements and questionnaires were used simultaneously to form a clearer picture of how the staff and patients perceive the indoor environment. The results show that the predicted optimal operative temperature for staff and patients, according to their clothing and level of activity, differs from their perception of the measured indoor temperature. Despite similarities, staff and patient needs cannot be summarised together. This is due mainly to the difference in their conditions, such as medication, level of activity and clothing. Moreover, calculations of the climate index (predicted mean vote, PMV) and dissatisfaction index (predicted percentage of dissatisfied, PPD) values, show that they do not correspond to the respondents’ perception of the indoor climate. There are indications that today’s recommendations and guiding principles cannot be applied to hospital environments without correction factors. This study highlights the need to elucidate and specify the requirements and recommendations for indoor environment in hospital wards. The air humidity can be a more important variable than formerly believed. This work illustrates that paying attention to air humidity is important; however the level desirable should first be confirmed from a medical point of view. The consequences of the requirements could thereafter be discussed and acted upon. Some guiding principles for a ward are proposed in this thesis. It should be a natural phase to discuss and analyse the need for air humidity requirements during the design and planning process in far more detail than today.