Masanori Shukuya

Verification of stochastic models of window opening behaviour for residential buildings

Based on the analyses of data from two distinct measurement campaigns conducted in residential indoor environments in Japan and Switzerland, we identify the specificities of occupants’ behaviour with respect to their interactions with windows, including the choice of opening angles for axial openings. As a first step, each dataset is analysed to develop separate predictive models which account for the specificities of window usage in the residential context. The predictive accuracy of these models is then challenged by validation on external data: using models inferred from data obtained from one survey, actions on windows are simulated for the other survey and the predictions are compared with observations. Dynamic models developed using data from office buildings as well as previously published models are also compared using this verification procedure. In the case of the Swiss dataset, these analyses demonstrate the ability of carefully formulated behavioural models developed from office environment data to reliably predict window usage in a residential context and vice-versa. However, we observe that the same models perform less satisfactorily in the prediction of window usage in Japan. From these results it seems that such models require specific calibration in the case of buildings equipped with an air-conditioning unit as was the case for the hot and humid summer climate of Japan.

Discomfort caused by wide-source glare

Abstract We report here on experiments to measure subjective response to intense light, or glare caused by a wide source. We have investigated three glare indices: the Building Research Station glare index; the CIE glare index and the Cornell daylight glare index. We have also examined the glare vote and have proposed a new glare evaluation scale, as well as asking the subject to vote on the conditions acceptability. The Cornell formula most accurately predicts glare discomfort, but it is found to be inadequate for a range of wide-source glare conditions. Both the discomfort sensation vote and the glare vote which we proposed correlate well with the percentage of subjects dissatisfied when looking directly at the light source.

Challenging the assumptions for thermal sensation scales

ABSTRACT Scales are widely used to assess the personal experience of thermal conditions in built environments. Most commonly, thermal sensation is assessed, mainly to determine whether a particular thermal condition is comfortable for individuals. A seven-point thermal sensation scale has been used extensively, which is suitable for describing a one-dimensional relationship between physical parameters of indoor environments and subjective thermal sensation. However, human thermal comfort is not merely a physiological but also a psychological phenomenon. Thus, it should be investigated how scales for its assessment could benefit from a multidimensional conceptualization. The common assumptions related to the usage of thermal sensation scales are challenged, empirically supported by two analyses. These analyses show that the relationship between temperature and subjective thermal sensation is non-linear and depends on the type of scale used. Moreover, the results signify that most people do not perceive the categories of the thermal sensation scale as equidistant and that the range of sensations regarded as ‘comfortable’ varies largely. Therefore, challenges known from experimental psychology (describing the complex relationships between physical parameters, subjective perceptions and measurement-related issues) need to be addressed by the field of thermal comfort and new approaches developed.

Integral Control of Health Hazards in Hospital Environment

Hospitals present complex indoor environment with various users, health hazards and specific activities. This paper classifies health hazards specific to the hospital environment (HE), defines their interactions and possible impacts on human health and summarizes recommendations for biological and chemical hazards. A detailed literature review clearly shows that there is no developed system or method for integral control of health hazards in HE. There is no appropriate technology available that would allow development of optimal thermal comfort conditions for individual users in HE. For integral control of physical hazards, an innovative low exergy (LowEx) system was designed and tested. The system enables individual control of thermal comfort parameters to meet the needs of various users in the same room. It enables the design of optional conditions for healthcare and treatment considering the different requirements of individual patients and thermally neutral zones for other users. The system application is presented in a model room for burns patient. The measured energy use was lower by 11–27% for space heating and by 32–73% for cooling, when using LowEx system as compared to the conventional system. Owning to its flexibility, the system can also be used for other potential users.

Development of human–body exergy balance model for a better understanding of thermal comfort in the built environment

This paper briefly describes the human–body exergy balance equation developed so far applying a variety of formulae derived from the fundamentals of thermodynamics, namely the concepts of wet/dry exergy associated with moist air and liquid water, warm/cool exergy transferred by radiation and convection. A couple of numerical examples of the whole human–body exergy balance are given and discussed in relations to mean radiant temperature, room air temperature, air velocity, and outdoor environmental temperature. We have found so far that it is very important to control the amount of thermal radiant exergy in room space both in winter and in summer.

Individualisation of personal space in hospital environment

The purpose of the paper is to test a Low Exergy heating and cooling system (LowEx system) that enables the creation of healing and comfort conditions for individual user with minimal possible energy use. The LowEx system was tested in a model room for burn patient and compared with the conventional one. Thermal comfort conditions were simulated for three individual users (burn patient, healthcare worker and visitor) energy use was measured. In a simulation, users were exposed to the required conditions for burn patient created with both systems. The LowEx system creates optimal conditions for burn patient with lower human body exergy consumption (hbExC) rate valid for thermoregulation, minimal evaporation, radiation and convection. For healthcare worker and visitor, the LowEx system creates individual thermal comfort zones. For the LowEx system, the measured energy use for heating was 11-27% lower and for cooling 32-73% lower than for the conventional system.

Visual comfort in the daylit luminous environment: Structural model for evaluation

In order to create a comfortable daylit luminous environment which can also contribute to conservation of fossil fuel, a hypothetical model structured in terms of physical quantities representing stimuli, sensory responses, and an overall evaluation is presented. This hierarchical model was tested by a pilot experiment conducted in a side-lit classroom with 147 subjects. A questionnaire was carefully prepared according to the hierarchical model, so that the overall evaluation could be expressed in terms of comfort sensation related to the sensory responses to brightness on the desk and to the veiling reflection on the sheet of paper on the desk. The brightness sensation on the desk was expressed by a function not only of the desk illuminance but also of the vertical illuminance. Deficiencies of the model on the basis of the experimental results and a modification of the model are also discussed.

Integral control of hospital environment

Hospital presents a complex indoor environment. Patients, healthcare workers/staff and visitors can not be treated as uniform group with the same needs, demands and conditions for thermal comfort. There is no method or system to provide optimal thermal comfort for everyone besides rational energy use for heating and cooling. The paper presents a design of a smart patient room in which thermal comfort conditions are highly controlled and energy use for heating and cooling minimized. Control system is based on the concept of individualization of personal space. With this respect two systems for heating and cooling are compared on the basis of thermal comfort calculations for two patients and measured energy use for heating and cooling. Human body exergy balance model is used together with building energy model. To control HE a smart system on the basis of fuzzy logic is applied. An individualized personal zone is designed.

A pilot experiment on a method for evaluating acceptability of a daylit luminous environment

Abstract 1. 1. We propose a hierarchical model as a hypothesis to evaluate comfort in lighting environments. 2. 2. The model consists of physical quantities such as stimuli, and visual sensations as the first response, and then overall evaluation. 3. 3. A pilot experiment in a side-lit classroom usng 147 subjects was made to examine this model. 4. 4. It was found that in the side-lit classroom the most effective answers for discrimination between “acceptable” and “not acceptable” were “the surface of desk was not considered dark” and “not to experience any reflectance of lighting on the sheet of paper on which they wrote”. 5. 5. Moreover all of the effective items relate to the task area, namely desk and blackboard, and this meant that subjects gave priority to workability in the classroom.

User-Centred Healing-Oriented Conditions in the Design of Hospital Environments

Design approaches towards energy efficient hospitals often result in a deteriorated indoor environmental quality, adverse health and comfort outcomes, and is a public health concern. This research presents an advanced approach to the design of a hospital environment based on a stimulative paradigm of healing to achieve not only healthy but also comforting conditions. A hospital room for severely burn patient was considered as one of the most demanding spaces. The healing environment was designed as a multi-levelled, dynamic process including the characteristics of users, building and systems. The developed integral user-centred cyber-physical system (UCCPS) was tested in a test room and compared to the conventional system. The thermodynamic responses of burn patients, health care worker and visitor were simulated by using modified human body exergy models. In a healing environment, UCCPS enables optimal thermal balance, individually regulated according to the user specifics. For burn patient it creates optimal healing-oriented conditions with the lowest possible human body exergy consumption (hbExC), lower metabolic thermal exergy, lower sweat exhalation, evaporation, lower radiation and convection. For healthcare workers and visitors, thermally comfortable conditions are attained with minimal hbExC and neutral thermal load on their bodies. The information on this is an aid in integral hospital design, especially for future extensive renovations and environmental health actions.