The main goal of this study is to determine a suitable set of thermal comfort criteria for naturally ventilated buildings in hot-humid climate by reanalysing the ASHRAE RP-884 database. The results reveal that the regression coefficient in the adaptive algorithm for naturally ventilated buildings in hot-humid climate is 0.52, which is steeper than ASHRAE Standard 55 and EN15251, even after considering the effects of indoor air speed. While higher air speed is effective to elevate indoor comfort temperature in hot-humid climate, the relationship between increased indoor air speed and increasing indoor operative temperature is also different from the above existing standards. In contrast, allowance for increased air speed may not be applicable to hot-dry climate. The daily mean outdoor air temperature may give more varied indoor operative temperatures that reflect the day’s conditions more closely compared to the monthly mean, running mean and prevailing mean outdoor air temperatures which tend to group together as a result of averaging. An Adaptive Comfort Standard for Hot-Humid Climate is proposed for application to naturally ventilated buildings in all tropical climates and hot-humid summer season of temperate climate based on these findings
Reanalysing the ASHRAE RP-884 Database to Determine Thermal Comfort Criteria for Naturally Ventilated Buildings in Hot-Humid Climate
Building Management for a Good Indoor Climate and Low Energy Use: How much coordination is needed between facility manager and technical manager?
In the Netherlands and most European countries it is usually not the Facility Manager who is in charge of the indoor climate and energy use of a building. This task is usually delegated to a technical service manager or sup-plier. This may seem logical because they both have their own specialism but in this case, the specialism’s are so far apart that the common interest of adding value through an optimal indoor climate, a low energy use and low exploitation costs is insufficiently served. This add-ed value can be measured in customer satisfaction, in terms of indoor climate and comfort, low absenteeism, higher production rates, low maintenance on HVAC systems and low energy consumption. Unfortunately, this added value is often not created and facility manag-er and technical manager do not work together, resulting in a poor indoor climate and high energy bills.
This paper presents the results of a qualitative research on the control of offices and educational buildings by the facility manager and technical manager, usually an installer. Daily practice is analyzed for a number of cases and complaints mismatches, actual indoor air quality, energy use and interventions are identified and analyzed. Best and worst practices are explained. The analysis also provides an integral model that covers the housings life cycle of the organization; design, imple-mentation, monitoring and adjustment of room usage and indoor climate. Finally recommendations are made for designers, builders and managers of HVAC systems and building management systems with attention for the necessary communication between technical and less technical administrators, such as facility managers.
Analysis of Seasonal Differences in Microclimate Formed in a Local Small City of Paddy Field Areas – A new approach using airborne remote sensing and CFD simulation
This paper examines the relationship between the seasonal land cover change and microclimate formed in a local small city of paddy field areas in Japan using airborne remote sensing data and CFD (Computational Fluid Dynamics) simulation. The land cover maps for three seasons, the 3D urban district model and the 3D surface temperature images are made using the airborne MSS (Multi-Spectral Scanner) data obtained in each season and GIS data in Tonami city, Toyama prefecture. These data are applied to the boundary conditions for the CFD simulation, and microclimate, including air current and air temperature distribution, are simulated for three seasons taking into account the seasonal land cover change. The simulation results are compared with the field measurement results for the microclimates in the site. These results quantitatively indicate that the control of microclimate by the paddy fields changes seasonally as its land cover changes through the year. In the summertime, the cooling effect of the paddy fields and the cool air current from the area contribute to the decrease in air temperature in the urbanized area.
An Interactive Performance-Based Expert System for Daylighting Design
Architects are increasingly using digital tools during the design process, particularly as they approach complex problems such as designing for successful daylighting performance. However, while simulation tools may provide the designer with valuable information, they do not necessarily guide the user towards design changes which will improve performance. This paper proposes an interactive, goal-based expert system for daylighting design, intended for use during the early design phase. The expert system consists of two major components: a daylighting knowledge-base which contains information regarding the effects of a variety of design conditions on resultant daylighting performance, and a fuzzy rule-based decision-making logic which is used to determine those design changes most likely to improve performance for a given design. The system gives the user the ability to input an initial model and a set of daylighting performance goals in the form of illuminance and daylighting-specific glare metrics. The system acts as a “virtual daylighting consultant,” guiding the user towards improved performance while maintaining the integrity of the original design and of the design process itself.
Outdoor Thermal Comfort in the Hot Arid Climate : The effect of socio-economic background and cultural différences
Climate-sensitive open spaces within cities may benefit the three dimensions of sustainability, affecting economical, social and environmental factors. Aiming to improve microclimatic conditions in urban spaces can enable people to spend more time outdoors, with the potential to influence the social cohesion of a space and increase economic activity. The wider aim of this research is to develop better understanding of the complex relation between microclimate and human behaviour in open public spaces in hot arid climates. Case studies were carefully selected in two different parts of the world (Marrakech in North Africa and Phoenix-Arizona in North America) to represent a variety of users in similar climatic context. This enabled us to study the effect of the socio-economic and cultural diversity on thermal comfort, behaviour and use of space. Field surveys included structured interviews with a standard questionnaire and observations of the human activities, along with microclimatic monitoring, carried out during winter and summer 2008 and 2009. The analysis consists of the microclimatic influence on the thermal sensation, preference and people attendance; the effect of psychological adaptation on subjective thermal evaluation of outdoor spaces; and finally, investigation of socio-economic and sociocultural impact on behaviour of people in outdoor space.
Architectural Pride and Environmental Prejudice: The effect of personal status, historical value, and indoor décor on occupants indoor environmental quality in offices
This paper reports on an important yet unexplored area of indoor comfort studies, the relationship between historical attributes of buildings, personal values, and indoor environmental quality (IEQ) of office spaces. For this study we employed a comparative case study design to assess environmental conditions and occupants’ behavioral responses of a year-long IEQ assessment of office settings inside ten adaptively reused historical palaces in Cairo Egypt. These palaces were selected based on their historical value, indoor décor, and their common mixedmode ventilation system. In addition to subjective IEQ evaluations by occupants, physical measurements of the settings’ layout, temperature, relative humidity, lighting intensities, air flow rates, and noise levels of the indoor office spaces were recorded during both the winter and summer seasons respectively. Focused interviews, questionnaires, field notes and occupants’ comfort diaries were used systematically to evaluate the occupants’ response towards their office environmental quality. The results of this investigation support the proposition that latent and symbolic qualities of the environment such as pride, status, historical value, and indoor décor attributes affect the overall perceived physical qualities of the environment in offices and workspaces. The findings provide both substantive and context specific knowledge to aid engineers, architects, and planners interested in the study topic.
Double-skin façade exhaustive simulation throughout combined thermal and daylight modelling. Application to optimal control
To optimize the comfort (visual and thermal) and energy savings, the topics related to solar protection are getting more and more important. Indeed it is necessary to use the maximum of the sun in winter (avoiding the glare) and to minimize transmitted radiation during the hot season in order to avoid the space overheating. The double-skin facades (DSF) satisfy these two goals. An exhaustive modelling of DSF has been realised. The studied DSF are equipped with Venetian blinds and provided with mechanical ventilation. The impact of this façade on the indoor environment in terms of visual and thermal ambiance is analysed. Our global simulation model is represented by a set of sub models, each characterising thermal behaviour of the DSF, natural and artificial lighting. All these simulation models are coupled with an office zone and then implemented in SIMBAD (HVAC Simulator for Building and Devices). Detailed descriptions of these implemented models as well the validation procedures are presented in the paper.
High Density, Low Energy: Achieving useful solar access for Dublin’s Multi-storey Apartment Developments
Solar energy has quantitative and qualitative benefits in the city, from reducing energy
consumption to improving both indoor and outdoor amenity. However, gaining access to
solar energy becomes increasingly difficult in high density developments, where orientation may not be optimal and obstruction is almost inevitable. Achieving a sensible balance between density and solar access is therefore a critical factor in sustainable urban design, however this balance will vary according to the climate, the site, and the brief of individual developments.
This paper documents how a multi-storey apartment block in Dublin can be designed with
respect to these factors in order to reduce energy consumption through solar access without compromising built density. The design research is divided into two distinct research phases. The first phase is concerned with the site massing, and uses solar envelopes to determine the highest buildable volume relative to solar geometry and occupancy patterns. The second phase of design focuses on individual apartment units within this optimised site massing, and assesses the useful benefits of solar access in terms of daylighting, passive solar heating, and potential for integration active solar systems. The final design is assessed in terms of the resulting density achieved, relative to the actual useful contribution of the sun to the developments total energy consumption.
Public “Living Room” Outdoor Comfort in Hot and Humid Climate
The proposed open space “living-room” is conceived as an extension of a private living space. As one of Asia’s most dense and developed cities, Hong Kong’s high-rise urban dwellings place constraints on activity within the home thus bringing a new relevance to the quality of open spaces in the city.
The aim of this project is to explore the possibility of environmental diversity within these public open spaces. A wider range of outdoor comfort can be achieved by providing a greater range of outdoor spaces offering different environments. In each, the sensation of experience, ranging from privacy to light, temperature, wind and sound will be considered. Microclimate will be created by zoning the space in relation to views, airflow and exposure to sunlight. The resulting thermal transitions will allow for a progressive adaptive approach of those circulating within the space. The design proposal will encourage use of outdoor space in a dense urban fabric in this hot and humid climate.