Predicted Percentage Of Dissatisfied Research Articles

A Multi-objective Optimization of Window and Light Shelf Design in Office Buildings to Improve Occupants’ Thermal and Visual Comfort

In office buildings, an efficient design of windows and using light shelves as a passive design strategy significantly influence the thermal and visual comfort of occupants while enhancing the productivity and health of users. This study proposes a multi-objective optimization for the optimal design of windows and light shelves in office buildings to improve occupants' comfort. Initially, a parametric model was developed using Grasshopper parametric software. Afterward, the Honeybee energy and daylight plugin was employed for simulating thermal and visual conditions, and finally, multi-objective optimization was conducted with the Octopus plugin. This plugin can determine the best solution as a compromise decision for maximizing occupants' comfort. In this paper, an office building in Tehran has been chosen as a case study. The decision variables are window-to-wall ratio (WWR), shading control strategy, viewpoint, the transmission of glass, light shelf length, and light shelf height. The objective functions of the study are the annual average Predicted Percentage of Dissatisfied (PPD) and the annual average Discomfort Glare Probability (DGP). According to the results, the proposed optimization model leads to an 18.5–70.1% and 9.3–57.1% reduction in DGP and PPD indexes, respectively. The study findings provide practical and useful instruction for architects to select optimal specifications of windows and light shelves to develop occupants' thermal and visual comfort in office buildings.

The effect of internal blinds on thermal comfort: An experimental analysis in an office room with radiant panels

This study investigated the impact of two types of internal blinds on the indoor thermal environment of a highly glazed office room in Istanbul during summer. The research examined four configurations: (i) no blinds, (ii) roller blinds, (iii) layered roller blinds in night mode and (iv) layered roller blinds in day mode. Measurements of air velocity, average radiation temperature, air temperature and relative humidity were conducted to assess thermal comfort. The findings revealed that internal blinds significantly influence thermal comfort in radiantly cooled office spaces during summer. Without blinds, the indoor environment only met ISO 7730 comfort category C, with average predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) values of 0.6 and 12.5%, respectively. However, with internal blinds, comfort categories A and B were achieved, resulting in improved thermal comfort levels, with average PMV and PPD values ranging from 0.2 to 0.3 and 6% to 7.5%, respectively. Roller blinds, in particular, proved highly effective in enhancing thermal comfort and reducing mean radiant and indoor air temperatures in highly glazed radiant cooling offices. This demonstrated their energy-efficient potential for improving indoor thermal comfort.

Enhancing indoor thermal comfort and sustainability: A solar-driven desiccant cooling and adsorption chiller system with environmental impact assessment

Addressing indoor thermal comfort in buildings located in hot and humid climates is a persistent challenge, demanding innovative cooling solutions that are both efficient and environmentally responsible. This paper introduces a new integration of a Phase Change Material (PCM)-based solar desiccant cooling system with an adsorption chiller, a setup designed to enhance indoor thermal comfort conditions while utilizing renewable energy sources. This research simultaneously leverages the heating and cooling capacities of the adsorption chiller, leading to an efficient system performance. The TRNSYS software is used to evaluate the system's behavior in a typical house with moderate cooling demand and characterized by high relative humidity. Two types of solar collectors, the evacuated tube and Wavy Direct Absorption Solar Collectors (WDASC), are evaluated to supply the required thermal energy, providing a comprehensive assessment of the system’s efficiency under different configurations. Additionally, the study conducts a comprehensive Life Cycle Assessment (LCA) to quantify the Global Warming Potential (GWP) of the systems. The results confirm the proposed system's capability to maintain indoor thermal comfort within acceptable Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) ranges. The evacuated tube collector showed marginally better performance (average PMV: 0.018, average PPD: 6.7 %) compared to the WDASC (average PMV: 0.075, average PPD: 7.3 %). Additionally, the evacuated tube collector demonstrates superior energy (75.68 %) and exergy (10.82 %) efficiencies compared to the WDASC. The system utilizing the evacuated tube collector surpasses the WDASC configuration, achieving a higher Coefficient of Performance (COP) of 0.47 compared to 0.41, and emitting lower GWP values of 0.0194 kg-CO2 per kWh of cooling capacity compared to 0.0201 kg-CO2. An analysis of Embodied Energy reveals that the adsorption chiller is the most significant contributor to lifecycle energy consumption, with a quicker Energy Payback Time (EPBT) for the evacuated tube system (2.75 years) compared to the WDASC system (3.94 years). This research thus contributes a highly efficient, sustainable, and environmentally friendly solution to the challenge of cooling in buildings, setting a new standard for future green building practices.

Influence of different heating systems on thermal comfort perception: a dynamic and CFD analysis

In this paper, we investigate the influence of different heating systems on the thermal comfort indexes, Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD), for a residential apartment located in Bologna (Italy). The apartment has an area of 40 m2 and is located on the ground floor of 4 floors building. The envelop consists in horizontal perforated bricks with internal thermal insulation material and two windows. The analyses are performed employing Trnsys, a commercial dynamic simulation software and Simcenter STAR-CCM+, a multiphysics computational fluid dynamics (CFD) software. The CFD analysis regards a steady condition of a typical winter day in Bologna. Thermal comfort indexes and thermal energy demand are studied comparing two different heating generation systems existing in the considered apartment: a condensing gas boiler coupled with radiators as terminal emitters and an air-to-air heat pump. By crossing the results obtained by the dynamical approach and by the CFD simulations, a two-objective methodology where energy consumption is minimised while thermal comfort is obtained, is presented.

A Study on Optimal Opening Configuration for Art Museum Exhibition Space Considering Daylight Performance, Indoor Thermal Comfort, and Energy Consumption

Skylights are an efficient means of daylighting in exhibition spaces, but their design presents significant challenges. Considering that daylight utilization profoundly impacts both the visual and thermal environments while affecting energy consumption, the early application of multi-objective optimization strategies becomes imperative. However, many optimization studies provide numerical references only, without delving into the characteristics of opening distribution. This study introduces an optimized exploration approach for openings based on grid subdivision and material parameter selection, targeting Useful Daylight Illuminance (UDI), Energy Use Intensity (EUI), and Predicted Percentage of Dissatisfied (PPD). Simulations and optimizations were performed using Honeybee and Octopus, focusing on the optimal configurations of four typical skylights in Fukuoka, Japan’s climate. The results demonstrate that this novel optimization approach improves metrics for each case and challenges traditional perceptions of daylight systems. Flexible and diverse opening configurations, formed through irregular layouts and material combinations, help achieve more ideal holistic environmental effects under different climatic conditions. Thus, we should provide these research findings as design guidelines for similar scenarios.

Analysis of the Influence of Chilled Water Temperature Setpoint on Thermal Comfort and Energy Consumption

AbstractThis study experimentally analysed the influence of chilled water temperature setpoints on thermal comfort conditions and energy consumption of an office building. Three chilled water temperature setpoints (10 °C, 12.5 °C, and 14 °C) were studied. The indoor environment variables (temperature and relative humidity) which are considered indicators of thermal comfort were recorded with data loggers for three consecutive days for each chilled water temperature setpoint (CWTS). Similarly, energy consumption was used as a metric to determine the system’s efficiency. The predicted percentage of dissatisfied (PPD) and predicted mean vote (PMV) indicators were computed and analysed using the Thermal Comfort/ASHRAE 55-2020 modelling tool from the centre for the built environment (CBE). Additionally, computational fluid dynamics (CFD) modelling and analysis were performed using ANSYS Fluent to study the indoor environment conditions of the office at the different chilled water temperature setpoints. A comparison between the calculated, measured, and predicted satisfaction of occupants was done. The results obtained when varying the chilled water temperature setpoints reveal that increasing the chilled water temperature setpoint (by 12%) reduces energy consumption per hour by 2% without compromising thermal comfort. The study demonstrated that the CWTS could be reset between 14 and 15 °C to reduce energy consumption and maintain thermal comfort. Moreover, the CFD model can be used to compare the indoor environmental characteristics of chiller systems.

Numerical Study of Thermal Comfort Evaluation in Naturally Ventilated Classrooms

The classroom is one of the important facilities in teaching and learning activities. Just like any other room, ensuring thermal comfort becomes a vital aspect for its occupants. This study aims to evaluate environmental conditions and the thermal comfort experienced by classroom occupants through numerical methods. The evaluation involves the integration of the Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) equations into Computational Fluid Dynamics (CFD) simulations using a user-defined function. Furthermore, extensive field measurements and questionnaire surveys are also employed to support the simulation process. The results indicate that the air temperature tends to be high, reaching 30.91°C. Meanwhile, the air velocity within the room, particularly in the occupied areas, is significantly low, with an average value of 0.04 m/s. According to the ASHRAE Standard 55, the classroom is perceived as uncomfortable, as evidenced by a PMV value of 1.38 and a PPD of 44.94%. Therefore, efforts are required to enhance the thermal comfort in the space.

Examining Occupant-Comfort Responses to Indoor Humidity Ratio in Conventional and Vernacular Dwellings: A Rural Indian Case Study

Optimum indoor humidity is often associated with comfort and overall well-being. Occupant comfort is often evaluated with a focus on “thermal comfort” using the PMV (predicted mean vote), PDD (predicted percentage of dissatisfied), and adaptive thermal comfort models. Humidity-determined comfort parameters, like skin and respiratory comfort, are well acknowledged in the scientific community, but strangely not considered for indoor comfort computations. This study proposes a new computational approach for describing and evaluating humidity-related skin comfort in buildings using skin temperature, evaporative loss, and skin wettedness as critical parameters. The Development and validation of the computational model was demonstrated through a case study in a rural Indian context. The case study involves real-time monitoring of indoor environmental parameters and humidity-determined occupant comfort votes recorded through a novel aggregated humidity comfort vote method. The simulation results were compared with the community comfort/health survey. It was observed that, even at neutral skin temperatures, an increase in skin wettedness increases the thermal sensation vote. Clothing varies according to gender, community, and personal preferences, influencing physiological parameters which determine comfort. The acceptable humidity ratio was found to be in the range of 17.4 to 22.6 g-wv/kg-da for Indian participants. Including humidity-related comfort parameters in building simulation tools would aid in selecting building materials for improved indoor comfort.

Impact of Indoor Environmental Quality on Students’ Comfort in High School Buildings during the Summer Season in an Extreme Climate

Maintaining a satisfactory indoor environmental quality (IEQ) is an integral element of improving occupant health and well-being. In particular, IEQ is an essential factor in some facilities, such as school buildings, to improve student academic performance. This study employed an objective and subjective measurement approach to assess IEQ in a government high school (GHS) and a private high school (PHS) located in Oman, which is characterized by its extreme hot climate. A total of 212 high school students were surveyed during the summer season across 10 different classrooms to ascertain their perception of IEQ situations. The results suggested that most of the observed IEQ factors, including air temperature, relative humidity, and lighting levels across the classrooms in GHS and PHS, satisfied the ASHRAE standard, except the indoor air temperature, which was slightly above the maximum threshold of the European Standard (EN). The average indoor sound levels (>60 dB) exceeded critical limits of 35 dB for school buildings, which may pose the risk of high annoyance (HA) to 30% of students. Satisfactory predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) scores were obtained from both schools when they were evaluated against the ASHRAE standard compared with the EN standard. The maximum proportion of the students reported their classroom’s air temperature (33%), relative humidity (25%), and air movement (47%) levels as not acceptable, and thermal comfort (33%), visual comfort (22%), and air quality (41%) as bad (P < 0.001). Multiple regression analysis revealed a strong linear relationship between indoor air temperature (R2 = 0.89) and other IEQ parameters, while PPD (R2 = 0.45) and PMV (R2 = 0.17) showed a weak relationship with outdoor environmental factors. Outdoor air temperature and humidity levels accounted for greater changes in indoor air temperature levels in the PHS than in the GHS. Providing increased urban vegetation, green façade, and retrofitting and the utilization of passive cooling could help improve IEQ in Oman schools.

The effect of water and vegetation elements as microclimate modifiers in buildings in hot and humid tropical climates

Thermal comfort in buildings is determined by several aspects of the climate, such as external and internal wind speeds. Therefore, this research aims to analyze the effect of water elements and vegetation as microclimate modifiers in buildings, to obtain thermal comfort through air velocity and flow analysis. In this context, the field analysis emphasized microclimate parameters. Two cases were also encompassed, namely the interior space of a residential building and a shopping center. By using field measurements with quantitative methods, data were obtained through the analysis of the PMV (thermal comfort index Predicted Mean Vote), PPD (Predicted Percentage of Dissatisfied), and TSV (Thermal Sensation Vote). This experiment was conducted to determine the influential levels of the building water and vegetation on comfort and the thermal environment. Data analysis was also processed using a statistical approach, with airflow being simulated through CFD (Computational Fluid Dynamics) method. The results showed that the air movement occurring in the building to the comfort and thermal environment, through architectural elements, reduced the temperature and humidity in the room. This was due to the heat radiation outside the building, leading to an impact on the effective air temperature for the thermal sensation of visitors. In this case, the movement of air in the building with the placement of architectural elements, such as water, vegetation, and good ventilation, was important for various activities. These activities included the following, (1) providing positive value, (2) improving the quality of the indoor environment, (3) maintaining the stability of the thermal environment at the building scale, and (4) achieving a comfortable thermal sensation.

Investigation of thermal comfort conditions by heat pump Hybridized with phase change Material-based solar desiccant cooling system

In response to the challenge of providing energy-efficient thermal comfort in hot and high-humidity cities, this study investigates innovative cooling systems that can mitigate issues of overcooling and excessive energy consumption seen in conventional air conditioning systems. Also, conventional cooling systems contribute to global warming by emitting high levels of greenhouse gases. In this research, two systems Phase Change Material (PCM)-based Solar Desiccant Cooling System (PSDC) and Heat Pump Hybridized with a PCM-based Solar Desiccant Cooling System (HP-PSDC) were investigated for a typical residential house located in Doha (Qatar), Vancouver and Toronto (Canada), and Bangkok (Thailand). According to the findings, the PSDC system provides thermal comfort conditions in Vancouver and Toronto with COP of 1.05 and 1.44, respectively. While in Doha and Bangkok, the innovative system that is HP-PSDC system has better performance when the COP (Coefficient of Performance) of the former is 4.98 and the latter is 4.5. The novelty of this work lies in the approach to balancing thermal comfort conditions with energy consumption. Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) were determined to set design criteria for the selection of the proper system based on the weather conditions of each city by using Design of Experiment (DOE) analysis. According to DOE, the dry bulb temperature, the wet bulb temperature, and the absolute humidity of the ambient air are three key characteristics that must be considered when choosing the appropriate system to provide thermal comfort conditions. It was found that if the wet bulb temperature of the building location is more than 21.5 °C, utilizing the HP-PSDC system can guarantee thermal comfort condition. However, for wet bulb temperatures less than 18.5 °C, the PSDC system is recommended. This research presents implications for the design of sustainable cooling systems, offering energy efficiency improvements and climate-specific system selection guidelines.

A Review of methodologies for analyzing thermal comfort in urban pedestrian pathways

According to the ANSI/ASHRAE Standard 55, thermal comfort is a subjective evaluation of thermal environment satisfaction. Therefore, the most challenging issue about thermal comfort is the assessment by subjective evaluation and addressing the case as a mental condition. Hence, The primary goal of the study is to determine which of the well-known thermal comfort indices is most suited for studying urban pedestrian movement. The present research method is based on the study of a wide range of research related to climatic comfort on the scale of urban space. The research has a review character and is set to analyze the different indices comparatively. In the analytical approach, the most significant factors which are compared are 1- PMV (predicted mean vote), 2- P4SR (four-hour predicted transpiration index), 3- HSI (heat stress index), 4- SET (standard effective temperature), 5- E.T.* (new effective temperature), 6- PPD (predicted percentage of dissatisfied) and 7- PET (Physiological Equivalent Temperature). The results show each component's advantages and disadvantages in analyzing thermal comfort in urban pedestrian pathways. The findings also underscored the importance of incorporating mixed methodologies to assist designers in making more accurate selections during urban planning. The most difficult issues that should be reconsidered in order to gain a better understanding of thermal comfort as an "adaptive" issue in urban pedestrian pathways are 1- Resetting the reference temperatures, 2- Readdressing the equations for upper and lower limits, 3- Providing more comprehensive databases (age, weight, gender, and thermal history), and 4- Reprogramming the acceptable temperature ranges based on individual expectations. Controls, layout, airflow, and humidity, among other design considerations, would be better emphasized by urban designers.

An XGBoost-Based predictive control strategy for HVAC systems in providing day-ahead demand response

Heating, ventilation and air-conditioning systems (HVAC), at demand side, are regarded as promising candidates to provide demand response to smart power grids by adjusting indoor temperature setpoint. However, the optimal control of indoor temperature setpoint with the constraint of indoor environment is a key issue. In this study, an XGBoost-based predictive control strategy is proposed for HVAC systems in providing day-ahead demand response. XGBoost (Extreme Gradient Boosting) models are developed to predict the variation of power use and indoor temperature. Several innovations are implemented to improve the performance of the control strategy, including dedicated generation of the initial population of genetic algorithm (GA) in rolling optimization, the use of a step-decreasing control horizon, and the separation of the sampling period and control action period. The strategy is validated on a TRNSYS-Python co-simulation test platform. Results show that the developed XGBoost models can achieve a high prediction performance of power use (CV-RMSE of 4.52%) and indoor temperature (CV-RMSE of 0.40%) in the coming 10 min with only using one-week historical data. The computation cost is reduced by 78% due to the dedicated generation of GA initial population while the control performance is not affected. Compared with the traditional operation, the proposed control strategy can reduce the total cost by as much as 27.30% and 33.6% while the weighted indoor temperature only increases by 0.14 K and 0.62 K, respectively. In test cases, the highest Predicted Mean Vote (PMV) is 0.72 and the corresponding Predicted Percentage of Dissatisfied (PPD) is 15.9%.

Analysis of Thermal Environmental in Buildings with Water and Landscape Elements as Microclimate Modifiers in Hot and Humid Tropical Climates

Thermal conditions in buildings are influenced by climatic conditions and are determined by the thermal performance of the building itself. The thermal condition is caused by the transfer of heat flow between the environment and the building. This study aims to analyze the value of temperature, humidity, solar radiation, and wind speed with the presence of the water element as a modifier of the microclimate in the building as well as thermal comfort for the adaptation of visitor behavior. The research focus is on the water element and the sensation of the thermal environment with public building objects. Field research based on ASHRAE 55 2020 and ISO 7730 standards. Four environmental parameters were measured, namely temperature, humidity, solar radiation, and air velocity. Data were obtained through field measurements using quantitative methods through analysis of the Predicted Mean Vote (PMV) thermal comfort index, Predicted Percentage of Dissatisfied (PPD), and Standard Effective Temperature (SET). The data is processed using a statistical approach and then simulated with 2-dimensional numerical data using the Thermal Comfort Tool (CBE) software after which it is compared with the thermal comfort index. PMV, PPD, and SET are generated and refer to the ASHRAE 55-2020 standard. Meanwhile, the sensation of the thermal environment based on behavioral adaptation was analyzed based on the results of the questionnaire answers using the thermal sensation vote (TSV). The results show that the analysis of the thermal environment in the context of the microclimate in the building, thermal comfort as well as water and landscape elements are important potentials that can provide positive values, improve quality, and maintain microclimate stability at the building scale and regional scale and need to be controlled and taken action. adaptive in buildings such as setting water elements and ventilation systems in buildings to provide a passive cooling effect on buildings.

IMPACT OF WINDOW SHADING ON THE THERMAL PERFORMANCE OF RESIDENTIAL BUILDINGS OF DIFFERENT FORMS IN JORDAN

Introduction: Window shading is considered one of the most effective passive design approaches that improves indoor thermal performance, minimizing the usage of HVAC and reducing energy consumption. Purpose of the study: We aimed to investigate the impact of external window shading on thermal performance of three existing residential buildings having different forms (rectangular, L-shaped, and U-shaped) in hot-dry climate in Amman, Jordan. Methods: Three types of shading, namely: vertical, horizontal, and combined, of different lengths (0.75 m, 1.00 m, and 1.25 m) were introduced to the existing buildings. The effect of those types of shading was studied using the OpenStudio SketchUp 2020 plugin and EnergyPlus simulation program. Results: It was established that vertical shading slightly improves the indoor air temperature in all building forms, while horizontal shading and combined shading improve the thermal performance of buildings to a more significant extent. Combined shading of 1.25 m in length shows the optimum behavior in all buildings since it reduces the indoor air temperature in the range of 2.6–3.3°C. Besides, it improves thermal sensation, which seem to be closer to the comfort zone, by reducing the predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) values as compared with the baseline situation without shading. In addition, the rectangular building demonstrated the best response for shading by showing the largest reduction in the indoor air temperature.

Indoor Air Quality of Beauty Salons in Commercial and Residential Areas of Camp, Abeokuta, Ogun State, Nigeria

Growing increase of beauty salons and exposure to associated chemical substances present serious concern of chemical hazards and health problems. This study assessed indoor air quality (IAQ) of selected beauty salons in commercial and residential areas of Camp settlement in Abeokuta, Ogun State, Nigeria using Aeroqual GasSensing Monitor and WindMate® Weather Station. Human thermal sensation (HTS) was computed using Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) Indices. Data collected were subjected to descriptive and inferential statistics. Findings showed TVOC exceeded permissible exposure limit (0.2 mg/m3) in all salons and critical safe level (2500 ppm) for CO2 was exceeded in one-third. Exceedance was observed in less than one-third of salons for P.M2.5 and P.M10, due to varying activities taking place per time, and location differences. Where detected, H2S was below permissible limit (1.4 mg/m3). HTS was above the acceptable thermal comfort levels (PMV: ±0.5; PPD: &lt;10%) in all salons. Generally, the IAQ indicates prevalence of inadequate ventilation, and portends increased exposure risk to hazardous chemical substances associated with salon activities. Therefore, formulation of policy, stipulating minimum operating standards and enforcement, alongside enlightenment campaign are necessary to promote human safety and prevent escalation of chemical related hazards in salons.&#x0D;

Digital Twin of HVAC system (HVACDT) for multiobjective optimization of energy consumption and thermal comfort based on BIM framework with ANN-MOGA

ABSTRACT This study proposes a novel Digital Twin framework of heating, ventilation, and air conditioning (HVACDT) system to reduce energy consumption while increasing thermal comfort. The framework is developed to help the facility managers better understand the building operation to enhance the HVAC system function. The Digital Twin framework is based on Building Information Modelling (BIM) combined with a newly created plug-in to receive real-time sensor data as well as thermal comfort and optimization process through Matlab programming. In order to determine if the suggested framework is practical, data were collected from a Norwegian office building between August 2019 and October 2021 and used to test the framework. An artificial neural network (ANN) in a Simulink model and a multiobjective genetic algorithm (MOGA) are then used to improve the HVAC system. The HVAC system is comprised of air distributors, cooling units, heating units, pressure regulators, valves, air gates, and fans, among other components. In this context, several characteristics, such as temperatures, pressure, airflow, cooling and heating operation control, and other factors are considered as decision variables. In order to determine objective functions, the predicted percentage of dissatisfied (PPD) and the HVAC energy usage are both calculated. As a result, ANN's decision variables and objective function correlated well. Furthermore, MOGA presents different design factors that can be used to obtain the best possible solution in terms of thermal comfort and energy usage. The results show that the average cooling energy savings for four days in summer is roughly 13.2%, and 10.8% for the three summer months (June, July, and August), keeping the PPD under 10%. Finally, compared to traditional approaches, the HVACDT framework displays a higher level of automation in terms of data management.

Multiobjective optimization of building energy consumption and thermal comfort based on integrated BIM framework with machine learning-NSGA II

Detailed parametric analysis and measurements are required to reduce building energy usage while maintaining acceptable thermal conditions. This research suggested a system that combines Building Information Modeling (BIM), machine learning, and the non-dominated sorting genetic algorithm-II (NSGA II) to investigate the impact of building factors on energy usage and find the optimal design. A plugin is developed to receive sensor data and export all necessary information from BIM to MSSQL and Excel. The BIM model was imported to IDA Indoor Climate and Energy (IDA ICE) to execute an energy consumption simulation and then a pairwise test to produce the sample data set. To study the data set and develop a prediction model between building factors and energy usage, 11 machine learning algorithms are used. The best algorithm was Group Least Square Support Vector Machine (GLSSVM), later employed in NSGA II as the building energy consumption fitness function using Dynamo software. An NSGA II multi-objective optimization model is designed to reduce building energy consumption and optimize interior thermal comfort (measured by the predicted percentage of dissatisfied (PPD)). The Pareto front is calculated, and the optimum point approach is used to find the best combination of building envelope characteristics, HVAC setpoints, shading parameters, lighting, and air infiltration. The feasibility and effectiveness of the developed framework are demonstrated using a case study of an upper secondary school building in Norway; the results show that: (1) The GLSSVM has a unique capacity to forecast building energy use with high accuracy: R2 of 0.99, an RMSE of 1.2, MSE of 1.44, and MAE of 0.89; (2) Building energy consumption and thermal comfort may be successfully improved by the GLSSVM-NSGA II hybrid technique, which reduces energy consumption by 37.5% and increases thermal comfort by 33.5%, respectively.

Indoor environmental quality in green certified office buildings

The presented paper deals with the assessment of selected indoor environmental quality (IEQ) factors, specifically the parameters of thermal comfort and indoor air quality (IAQ), in two buildings of a modern office complex. Both buildings are LEED certified. The monitoring of selected IEQ risk factors took place in selected office spaces (cell and open-space offices) representative of all occupied areas under operating conditions. The results of real measurements of IAQ parameters indicate that the monitored office spaces in both buildings did not exceed the required limits set by the LEED certification system. The measured parameters of thermal comfort were within the permissible legislative limits and the results of Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) indices show that a suitable level of thermal comfort can be expected in the given buildings during their occupancy. Based on the results of real measurements, it can be stated that both office buildings actually meet the LEED criteria for IAQ and guarantee a healthy and comfortable working environment for their occupants.

Passive Discomfort Index as an alternative to Predicted Mean Vote and Predicted Percentage of Dissatisfied to assess occupant’s thermal discomfort in dwellings

Besides energy poverty, a certain tolerance to discomfort justifies Portugal’s low heating energy consumption. Once Portuguese buildings stock, previous to 1990, has a weak energy performance, it is crucial to reflect on how to make renovations with more assertive benefits (besides energy), such as those related to the health and comfort of occupants. Hence, we have studied a single house in the TRNSYS dynamic simulation tool. We performed a sensitivity analysis by simulating the same building in three locations based on Portuguese climatic winter zones: I1 — Santarém, I2 — Santa Maria da Feira, and I3 — Guarda, for two ranges of wall insulation thickness, in free float. Considering Fanger’s Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) as the Passive Discomfort Index IDP, results suggest that lowering 20 mm on the insulation thickness does not substantially impact occupants’ discomfort in winter. As the variations between scenarios considering PPD > 15%, PMV < −1, or IDP (Tair < 18 °C) are very similar, IDP could be an alternative to PMV/PPD for assessing thermal discomfort in dwellings.