Forty years of Fanger’s model of thermal comfort: comfort for all?

The predicted mean vote (PMV) model of thermal comfort, created by Fanger in the late 1960s, is used worldwide to assess thermal comfort. Fanger based his model on college-aged students for use in invariant environmental conditions in air-conditioned buildings in moderate thermal climate zones. Environmental engineering practice calls for a predictive method that is applicable to all types of people in any kind of building in every climate zone. In this publication, existing support and criticism, as well as modifications to the PMV model are discussed in light of the requirements by environmental engineering practice in the 21st century in order to move from a predicted mean vote to comfort for all. Improved prediction of thermal comfort can be achieved through improving the validity of the PMV model, better specification of the model's input parameters, and accounting for outdoor thermal conditions and special groups. The application range of the PMV model can be enlarged, for instance, by using the model to assess the effects of the thermal environment on productivity and behavior, and interactions with other indoor environmental parameters, and the use of information and communication technologies. Even with such modifications to thermal comfort evaluation, thermal comfort for all can only be achieved when occupants have effective control over their own thermal environment. PRACTICAL IMPLICATIONS: The paper treats the assessment of thermal comfort using the PMV model of Fanger, and deals with the strengths and limitations of this model. Readers are made familiar to some opportunities for use in the 21st-century information society.     

Evaluation of natural illumination and thermal comfort conditions in the Ribeirao Preto’s Technological Village

The results of post-occupancy surveys of the 11 different construction systems used in the dwellings of the Technological Village of Ribeirao Preto are analyzed. The analyses focus on evaluating the natural illumination and thermal comfort conditions in selected habitation units after 2 years of use. All systems were devised to provide living conditions to low-income families with low purchasing power and, most importantly, to disseminate construction technologies adapted to, and appropriate for, this specific region of the country. The results indicate that the methodology employed is not appropriate using only classical factors to assess the illumination conditions, i.e. illuminance level and daylight factor, for a direct quantification of the illumination. The isolated use of these factors can result in distortions. The evaluation of the environmental conditions is relevant to observe that there can be differences between theoretical thermo-physical properties and actual features of the materials and construction systems analyzed.     

Control efficiency optimization and Sobol’s sensitivity indices of MTMDs design parameters for buffeting and flutter vibrations in a cable stayed bridge

This paper studies optimization of three design parameters (mass ratio, frequency ratio and damping ratio) of multiple tuned mass dampers MTMDs that are applied in a cable stayed bridge excited by a strong wind using minimax optimization technique. ABAQUS finite element program is utilized to run numerical simulations with the support of MATLAB codes and Fast Fourier Transform FFT technique. The optimum values of these three parameters are validated with two benchmarks from the literature, first with Wang and coauthors and then with Lin and coauthors. The validation procedure detected a good agreement between the results. Box-Behnken experimental method is dedicated to formulate the surrogate models to represent the control efficiency of the vertical and torsional vibrations. Sobol’s sensitivity indices are calculated for the design parameters in addition to their interaction orders. The optimization results revealed better performance of the MTMDs in controlling the vertical and the torsional vibrations for higher mode shapes. Furthermore, the calculated rational effects of each design parameter facilitate to increase the control efficiency of the MTMDs in conjunction with the support of the surrogate models.     

Genetic algorithms based optimization of artificial neural network architecture for buildings’ indoor discomfort and energy consumption prediction

Growing concerns about energy consumption reduction and comfort improvement inside buildings make it more and more necessary to be able to predict with fine precision building’s heating loads and indoor discomfort. This article proposes a method based on genetic algorithms (GAs) to optimize the architecture, training parameters and inputs of an artificial neural network (ANN). The ANN is doomed to predict energy consumption and indoor discomfort in future work on the development of an on-line method for control setting optimization. Simple and advanced controllers were used in this study: ON-OFF, PID and fuzzy controllers. Validation of the optimized ANN showed good prediction accuracy, as regression coefficients R ² for consumption and discomfort were respectively greater than 0.77 and 0.84 for the three tested controllers. Various prediction “distances” and ANN training data quantities were tested. Conclusion is that prediction at a 2-hour “distance” and a 3-day quantity of data are the best tested optimization conditions.     

Advanced fuzzy logic controllers design and evaluation for buildings’ occupants thermal–visual comfort and indoor air quality satisfaction

The aim of this paper is to present and evaluate control strategies for adjustment and preservation of air quality, thermal and visual comfort for buildings’ occupants while, simultaneously, energy consumption reduction is achieved. Fuzzy PID, fuzzy PD and adaptive fuzzy PD control methods are applied. The inputs to any controller are: the PMV index affecting thermal comfort, the CO₂ concentration affecting indoor air quality and the illuminance level affecting visual comfort. The adaptive fuzzy PD controller adapts the inputs and outputs scaling factors and is based on a second order reference model. More specifically, the scaling factors are modified according to a sigmoid type function, in such a way that the measured variable to be as closer as possible to the reference model. The adaptive fuzzy PD controller is compared to a non-adaptive fuzzy PD and to an ON–OFF one. The comparison criteria are the energy required and the controlled variables response. Both, energy consumption and variables responses are improved if the adaptive fuzzy PD type controller is used. The buildings’ response to the control signals has been simulated using MATLAB/SIMULINK.     

Quantifying stakeholders’ influence on energy efficiency of housing: development and application of a four-step methodology

Identifying stakeholders’ influence on project outcomes, prioritizing their importance and managing their interests accordingly is an effective strategy for maximizing benefits for organizations. Quantifying the influence of stakeholders on energy efficiency of housing allows for the development of an engagement plan that takes into consideration stakeholders’ diverse goals, needs, levels of expertise, knowledge, authority, connectivity and closeness to decision-making processes throughout the different stages of the housing procurement. We present a theoretical approach for quantifying the influence of stakeholders on the thermal performance of housing. The quantification methodology builds on a number of stakeholder management approaches and is applied to Australian case studies for reflection and sense making. The quantification of the degree of influence is calculated by combining the rankings of stakeholders in six attributes that affect their influence on a building’s energy efficiency outcomes. Quantifying human influence on buildings’ energy efficiency can help future researchers and housing industry stakeholders in integrating the human aspect with technological, technical, economic and regulatory aspects to optimize the performance outcomes of energy efficient housing.     

Thermal comfort in care homes: vulnerability,responsibility and ‘thermal care’

Care homes are a distinctive setting for the management of thermal comfort due to the expectations involving the provision of both a home environment and caring service. Based on six UK case studies, the care home setting is investigated for how owners, managers and staff understand thermal needs and how their management of thermal comfort is shaped. The core function of good quality care is understood as closely related to the provision of thermal comfort. The association between ‘old and cold' and the obligations that follow for the provision of care are deeply entrenched in activities: such as the provision of hot drinks, use of blankets and the non-stop operation of heating systems. The responsibility for the provision of ‘thermal care' for residents is challenging and complicated by the diversity of people living (and working) together, their occupation of communal spaces, and the interactions between the means of providing thermal comfort and physical safety. The wider implications are identified for the uptake of sustainable technology, patterns of thermal-related vulnerability and, most significantly, for how the ethics, agency and relationality of thermal care provision are to be understood. Future research needs and directions are considered.     

Zipf’s and Gibrat’s laws for migrations

This paper analyses the evolution of the size distribution of the stock of immigrants in the period 1960–2000. In particular, we are interested in testing the validity of two empirical regularities: Zipf’s law, which postulates that the product between the rank and size of a population is constant; and Gibrat’s law, according to which the growth rate of a variable is independent of its initial size. We use parametric and nonparametric methods and apply them to absolute (stock of immigrants) and relative (migration density, defined as the quotient between the stock of immigrants of a country and its total population) measurements. We find that both the stock of immigrants and migration density follow similar size distributions to those of cities and of countries. Contrary to what traditional migrations models predict, growth in the stock of immigrants is independent of the initial stock. Moreover, the growth of migration density shows a divergent behaviour, which could be explained by the lower birth rates of host countries and the reduction in the cost of emigration produced by the presence of a previous stock of immigrants in the country.     

Challenges for capturing and assessing initial embodied energy: a contractor’s perspective

Initial embodied energy includes energy use during material, transportation, and construction life cycle phases up to project practical completion. Contractors have an important role to play in reducing initial embodied energy levels due to their significant involvement in preconstruction and onsite construction activities. Following an extensive literature review a comprehensive framework was designed to highlight the significance of initial embodied energy levels relative to specific construction packages, activities and subcontractors. This framework was then applied to a new UK industrial warehouse project using a case study approach. Capturing information from a live project during the entire construction phase helped highlight the practical challenges inherent when capturing and assessing initial embodied energy levels. A series of contractor current practices was reviewed to determine their compliance with the framework requirements. The findings revealed that the ground and upper floor, external slab and frame were the most significant construction packages in terms of embodied impacts. Many challenges embedded within the contractor’s current practices in terms of data detail, legibility, and terminology were also revealed. The framework provides a practical approach for initial embodied energy assessment which can readily be adopted by contractors to help highlight opportunities to increase efficiency.     

Investigation of BTEX removal efficiency using the electrolytic oxidation and Fenton’s reaction

The removal of benzene, toluene, ethyl benzene, and xylene (BTEX) using the electrolytic oxidation or Fenton’s reaction has been studied. The value of current and pH value were shown to produce a significant effect on electrolytic oxidation of BTEX. More than 95% of BTEX could be removed at 500 mA current within 8 hours. In the case of Fenton’s reaction it was established that more than 95% of BTEX could be removed at pH 4 with an addition of hydrogen peroxide in the amount of 12 mg/dm³. The treatment cost based on electrolytic oxidation amounted to between $0.04 and $5.1 USD/m³. For Fenton’s reaction, the treatment cost was between $0.16 and $0.65/m³. The costs of electrolytic oxidation and Fenton’s reaction were similar to the cost of electrodialysis and cheaper than the freeze–thaw and evaporation; however, these costs were higher than for air flotation and the use of anoxic/aerobic granular activated carbon.     

A combined experimental and simulation method for appraising the energy performance of green roofs in Ningbo’s Chinese climate

A passive means of lowering the energy demand of buildings is the application of green roofs. The complexity between heat and moisture exchanges in green roof layers and the large variations of green roof types make the need for experimental or simulation assessments necessary for quantifying the energy benefits from green roofs. The current treatment of green roofs in simulation programs is either over-simplistic, for example by ignoring heat and moisture exchanges such as evapotranspiration, or the more advanced models have limitations and require inputs that are rarely available in practice. In this paper a combination of experimental and modelling techniques are used to assess the potential heating and cooling load reductions from the application of green roofs in the subtropical climate of Ningbo in China. The method provides a generalised energy performance assessment of green roofs in Ningbo by overcoming the limitations of existing green roof simulation models.     

A Bayesian network model for the optimization of a chiller plant’s condenser water set point

To implement the condenser water set point optimization, one can employ a regression model. However, existing regression-based methods have difficulties to handle non-linear chiller plant behaviour. To address this problem, we develop a Bayesian network model and compare it to both a linear and a polynomial regression model via a case study. The results show that the Bayesian network model can predict the optimal condenser water set points with a lower root mean square deviation for both a mild month and a summer month than the linear and the polynomial models. The energy-saving ratios by the Bayesian network model are 25.92% and 1.39% for the mild month and the summer month, respectively. As a comparison, the energy-saving ratios by the linear and the polynomial models are less than 19.00% for the mild month and even lead to more energy consumption in the summer month (up to 3.73%).     

Occupants’ impact on indoor thermal comfort: a co-simulation study on stochastic control of solar shades

This paper investigates the impact of manually operated solar shades on indoor thermal comfort. A developed stochastic model for manual solar shades was modelled in Building Controls Virtual Test Bed, which was coupled with EnergyPlus for co-simulation. Movable solar shades were compared with two unshaded windows (clear double-pane and low-e double-pane). Two objective indices (room base temperature and transmitted solar radiation) and one subjective index (modified predicted mean vote (PMV) index (PMVrad) that considers solar radiation on the human body) were used to evaluate the indoor thermal performance. Results show that external solar shades achieve the best performance in terms of all three indices, especially for PMVrad, hours of comfortable conditions are higher than unshaded windows by 20.6–37.3%. Despite achieving relatively high performance, solar shades are operated infrequently and for about 30% of work time they are not adjusted appropriately, leading to a decrease in indoor thermal comfort.     

Thermal perceptions,general adaptation methods and occupant's idea about the trade-off between thermal comfort and energy saving in hot–humid regions

A field study conducted in workplaces and residences in Taiwan is carried out to clarify two questions in detail: (1) do people in the tropical climate regions demonstrate a correlation between thermal sensation and thermal dissatisfaction the same as the PMV–PPD formula in the ISO 7730; and (2) does the difference in opportunities to choose from a variety of methods to achieve thermal comfort affects thermal perceptions of occupants? A new predicted formula of percentage of dissatisfied (PD) relating to mean thermal sensation votes (TSVs) is proposed for hot and humid regions. Besides an increase in minimum rate of dissatisfied from 5% to 9%, a shift of the TSV with minimum PD to the cool side of sensation scale is suggested by the new proposed formula. It also reveals that the limits of TSV corresponding to 80% acceptability for hot and humid regions are −1.45 and +0.65 rather than −0.85 and +0.85 suggested by ISO 7730. It is revealed in the findings that the effectiveness, availability and cost of a thermal adaptation method can affect the interviewees' thermal adaptation behaviour. According to the discussion of interviewees' idea about the trade-off between thermal comfort and energy saving, it is found that an energy-saving approach at the cost of sacrificing occupant's thermal comfort is difficult to set into action, but those ensure the occupant's comfort are more acceptable and can be easily popularized.     

Innovative potential for development of Europe’s neighbouring countries and regions

The European Neighbourhood Policy (ENP) is intended to promote development in bordering states and regions positioned along a broad arc from Morocco to Ukraine to become more friendly, stable, and prosperous. The policy offers limited but attractive terms of association with selected non-EU members concerning trade, mobility, innovation, and assistance in exchange for the adoption of important Western features that comprise the Community Acquis. The theme of this special issue hews closely to the economic development goals of the ENP by examining forces and factors that underlie the ability of neighbouring regions and countries to acquire and exploit innovative technologies, which are seen as the key element of a successful ENP.     

Thirty years of action for energy efficiency in buildings: what are the results?

In the autumn of 1973 a first energy crisis swept over the industrialized world. In 1979 a second followed. The first reactions in the West reflected panic, but soon a correcting policy emerged with rational use of energy as one of the corner stones. From the beginning, buildings got special attention. Their share in the annual national end energy consumption, in fact, was unexpectedly high, while less consumption of highly valued energy sources looked affordable without jeopardizing building usability. On the contrary, better was possible with less. One may expect that three decennia later, the results of such policy should be visible in terms of less energy consumed in buildings. This is not the case, at least not in Flanders, Belgium. Many reasons explain that anomaly. The average principal, designer, builder and contractor is not interested in energy efficiency. Investment costs and not future annual costs are the main concern. Legislation has been introduced reflecting a far too optimistic view on citizenship and thus, without any enforcement policy. The housing and tertiary building stock still expands, with a clear prosperity‐linked trend towards detached dwellings with low compactness and large floor area. Urban planning remains business as usual. And finally, policy makers forgot to consider rebound effects and the impact of lazy workmanship when predicting the efficiency of fabric and building services related measures, resulting in an overestimation of future avoided energy use, while at the same time they underestimated the inertia of such large system as the existing building stock, given the low retrofit and substitution rate.     

Comfort-related feedforward information: occupants’ choice of cooling strategy and perceived comfort

ABSTRACT

Approaches to provide feedforward information to building occupants about the impact of potential actions on individual thermal comfort levels are scarce. Even less is known about the effect of such information on the decision process of occupants to interact with their built environment and their level of comfort after such decisions. In a naturalistic study, participants (N?=?76) were given a choice of four actions to counteract thermal discomfort induced by constantly rising room temperatures: removing a piece of clothing, opening the window, switching on the ceiling fan or switching on the air-conditioning. After receiving information about the potential change in comfort and energy consumption of these options, they had to confirm or revise their choice. The vast majority of participants initially chose to open the windows (N?=?28) or remove a piece of clothing (N?=?37); only a few chose the ceiling fan (N?=?2) or the air-conditioning (N?=?9). About one-third (N?=?23) revised their choice of action; most of them (N?=?15) indicated an influence from the provided information. In conclusion, feedforward information can be a useful tool to combat overheating problems by increasing energy-aware behaviour and thermal acceptance.