scholarly journals Abatement of the Increases in Cooling Energy Use during a Period of Intense Heat by a Network-Based Adaptive Controller

2021 ◽  
Vol 13 (3) ◽  
pp. 1353 ◽  
Author(s):  
Jonghoon Ahn
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Energy Use ◽  
Deterministic Model ◽  
Thermal Conditions ◽  
Adaptive Controller ◽  
High Energy ◽  
Comfort Level ◽  
Indoor Environmental Quality ◽  
Comfort Indices

Various methods to control thermal conditions of building spaces have been developed to investigate their performances of energy use and thermal comfort in the system levels. However, the high control precision used in several studies dealing with data-driven methods may cause energy increases and the high energy efficiency may be disadvantageous for maintaining indoor environmental quality. This study proposes a model that optimizes the supply air condition to effectively reach the setting values by two-way controls of the supply air conditions. In such a process, if the results of the thermal comfort level are outside the range of the initial setting values, an adaptive model starts to work to send additional signals to adjust the set-point temperature. In order to assess its efficiency, the conventional thermostat model and fuzzy deterministic model are adopted as comparators. Comparing the results of the proposed network-based model with conventional control models, an improved control performance from 15.5% to 29.3% in thermal comfort indices was identified, as well as an over 30% improvement in energy efficiency. As a consequence, the network-based adaptive control rule supervising thermal comfort indices properly operates to abate increases in its energy use without compromising its thermal comfort. This performance can be significant in places where many spaces are woven at high density, and in situations where better thermal comfort can increase users’ workability and productivity.

scholarly journals Performance Analyses of Temperature Controls by a Network-Based Learning Controller for an Indoor Space in a Cold Area

2020 ◽  
Vol 12 (20) ◽  
pp. 8515 ◽  
Author(s):  
Jonghoon Ahn
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Use ◽  
Fuzzy Logic Controller ◽  
Sustainable Use ◽  
Adaptive Controller ◽  
Comfort Level ◽  
Effective Control ◽  
Control Precision ◽  
Neural Network Controller

For the sustainable use of building spaces, various methods have been studied to satisfy specific conditions required by the characteristics of space types and the energy use in operation. However, several effective control approaches adopting the latest statistical tools may have problems such as higher control precision increases energy consumption, or lower energy consumption decreases their control precision. This study proposes an optimized model to reach the indoor set-point temperature by controlling the amount of heating supply air and its temperature and investigates the efficiency of an adaptive controller to maintain indoor thermal comfort within setting ranges. In the consistency of the comfort level, the fuzzy logic controller was found to be 1.76% and the artificial neural network controller to be 17.83%, respectively, more efficient than the conventional thermostat. In addition, for energy use efficiency, both of the controllers were confirmed to be over 3.0% more efficient. Consequently, the network-based controller with the adaptive controller checking comfort levels effectively works to improve both energy efficiency and thermal comfort. This improvement can be significant in places such as commercial high-rises, large hospitals, and data centers where many spaces are intensively woven with appropriate thermal environments to maintain users’ workability.

scholarly journals Improvement of the Performance Balance between Thermal Comfort and Energy Use for a Building Space in the Mid-Spring Season

2020 ◽  
Vol 12 (22) ◽  
pp. 9667
Author(s):  
Jonghoon Ahn
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Use ◽  
Learning Algorithm ◽  
Adaptive Controller ◽  
Comfort Level ◽  
Adaptive Model ◽  
Comfort Levels ◽  
Proposed Model ◽  
High Consistency

In thermal controls in buildings, recent statistical and data-driven approaches to optimize supply air conditions have been examined in association with several types of building spaces and patterns of energy consumption. However, many strategies may have some problems where high-control precision may increase energy use, or low energy use in systems may decrease indoor thermal quality. This study investigates a neural network algorithm with an adaptive model on how to control the supply air conditions reflecting learned data. During the process, the adaptive model complements the signals from the network to independently maintain the comfort level within setting ranges. Although the proposed model effectively optimizes energy consumption and supply air conditions, it achieves quite improved comfort levels about 14% more efficient than comparison models. Consequently, it is confirmed that a network and learning algorithm equipped with an adaptive controller properly responds to users’ comfort levels and system’s energy consumption in a single space. The improved performance in space levels can be significant in places where many spaces are systematically connected, and in places which require a high consistency of indoor thermal comfort. Another advantage of the proposed model is that it properly reduces an increase in energy consumption despite an intensive strategy is utilized to improve thermal comfort.

scholarly journals Thermal Control Processes by Deterministic and Network-Based Models for Energy Use and Control Accuracy in a Building Space

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 385
Author(s):  
Jonghoon Ahn
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Deterministic Model ◽  
Learning Algorithm ◽  
Fuzzy Model ◽  
Weather Condition ◽  
Thermal Control ◽  
Comfort Level ◽  
Deterministic Models ◽  
Climate Conditions

Various control approaches for building thermal controls have been studied to improve the energy use which determines a large part of the spatial thermal quality. This research compares the performance of deterministic models and a network-based model to examine the aspects of both energy consumption and thermal comfort. The single-switch deterministic model immediately responds to indoor thermal conditions, but the network-based model sends better-fit signals derived from learned data reflecting seven different climate conditions. As a result, the network-based model improves the thermal comfort level by about 6.1% to 9.4% and the energy efficiency by about 1.8% to 39.5% as compared to a thermostat and a fuzzy model. In the case of a specific weather condition, it can be confirmed that the process of finding efficient control values based on the network-based learning algorithm is more efficient than the conventional deterministic models.

scholarly journals Improving Optimization Solution for Facility Layout Problem with Thermal Comfort

2020 ◽  
Vol 76 (3) ◽  
pp. 49-61
Author(s):  
Noorhadila Mohd Bakeri ◽  
Mohd Faizal Omar ◽  
Mohd Nasrun Mohd Nawi ◽  
Faizal Baharum
Keyword(s):  
Thermal Comfort ◽  
Energy Use ◽  
Energy Savings ◽  
Facility Layout ◽  
Classical Problem ◽  
High Energy ◽  
Comfort Level ◽  
Layout Problem ◽  
Facility Layout Problem ◽  
Satisfaction Rate

Facility Layout Problem (FLP) can be considered as a classical problem in quantitative studies. However, the literature in FLP are largely neglected the thermal comfort as part of the objective function. Today, energy savings for buildings are a major concern in the world as they cover a big portion of energy use. The public room consumes high energy use because of its ability to occupy many people at one time. Issues arise when each person has a dissimilar thermal satisfaction rate, while each area in a room provides a different temperature. There are many factors that influence the people dispersion in the room including the facility layout. However, it is really testing to handle an air-conditioning control () system by considering the mention factors to ensure the thermal satisfaction is increased and energy is reduced. Since lack of report on thermal factors in Facility Layout Problem (FLP) area, this work aims to optimize the temperature setting of an system at the best point and achieving the finest plan for the facility layout in a room. Further, our ultimate goals to maximize the thermal comfort level and reduce energy consumption are able to accomplish. A non-linear mathematical model is utilized to optimize the thermal satisfaction rate () and room layout. At the end of the article, we proposed an Evolutionary Algorithm (EA) to find a quality solution or near optimal since it is hard to solve this problem in a reasonable time.

Comfort-energy nexus in naturally ventilated affordable mass housing with alternative constructions in the developing world

2021 ◽  
Author(s):  
Roshmi Sen ◽  
Shankha Pratim Bhattacharya ◽  
Subrata Chattopadhyay
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Thermal Load ◽  
Mixed Mode ◽  
Developing World ◽  
Assessment Model ◽  
Strong Positive Correlation ◽  
Mass Housing ◽  
The Past ◽  
Comfort Indices

<p>There is a strong positive correlation between thermal comfort quality experienced inside a building and its energy efficiency. This is more obvious in case of mechanically ventilated spaces where the energy gains are directly related to the thermal load, as compared to free running or naturally ventilated spaces. Current state of arts assess the energy efficiency of building envelops in terms of the cumulative thermal load in the operating phase of the building that are catered by mechanical ventilations. Our study aims at addressing this gap of research in assessing the thermal comfort quality of naturally ventilated residential living spaces. Our study is designed in a warm-humid climate setting and in the context of affordable mass housing in the developing world where mechanical ventilation is unaffordable or affordable only for a definite period of the day and during peak summer seasons; such buildings are said to be operating in temporal mixed mode.</p><p>Affordable mass housing constitutes 95% housing demand in the residential sector in India. Various alternative materials and composite roofing and walling envelops have been envisioned in the past decade for such constructions, however, their effectiveness in terms of comfort quality has not been assessed for naturally ventilated envelops. Our study introduces a model to assess the thermal performance of naturally ventilated bedrooms constructed with alternate building envelop configurations. We attempt to review  and compare alternative walling technologies and the currently emerging mass housing construction systems in India with the base case housing envelop constructions commonly in practice in India that use ordinary burnt clay brick walls and reinforced concrete roofs. We compare the thermal comfort purveyed in the indoor bedroom spaces using the adaptive thermal comfort model in EN15251 as thermal neutrality temperature. We assess and compare alternative envelop performance using two measuring thermal comfort indices suited for naturally ventilated scenarios - the discomfort hours index and the cooling indoor degree hours index. Discomfort hours measures the number of hours of discomfort experienced during the summer solstice and spring equinox months whereas the cooling indoor degree hours measures the cumulative average temperature elevation from the comfort temperature in the hours marked as discomfort hours. In our study, light gauge steel framed structure with foam concrete filling records the minimum number of discomfort hours, however purveys maximum cooling indoor degree hours.</p><p>The above two comfort indices have not been compared in the past to assess the thermal comfort quality in naturally ventilated or temporal mixed mode buildings. Our study frames a thermal comfort assessment model for naturally ventilated envelops and thereby offers a paradigm shift from life cycle cooling load minimization models which are appropriate for mechanically conditioned spaces. Our observations are also important for mass housing envelop selection and in the context of the current policy frameworks in the developing world, aimed at minimizing the projected demand for residential space cooling and future energy footprints in the housing sector.</p>

scholarly journals Spatial and Behavioral Thermal Adaptation in Net Zero Energy Buildings: An Exploratory Investigation

2020 ◽  
Vol 12 (19) ◽  
pp. 7961 ◽  
Author(s):  
Shady Attia
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Energy Use ◽  
Thermal Adaptation ◽  
Building Energy ◽  
Building Energy Efficiency ◽  
Zero Energy ◽  
Net Zero Energy ◽  
Net Zero ◽  
Energy Efficiency Standards

Climate responsive design can amplify the positive environmental effects necessary for human habitation and constructively engage and reduce the energy use of existing buildings. This paper aims to assess the role of the thermal adaptation design strategy on thermal comfort perception, occupant behavior, and building energy use in twelve high-performance Belgian households. Thermal adaptation involves thermal zoning and behavioral adaptation to achieve thermal comfort and reduce energy use in homes. Based on quantitative and qualitative fieldwork and in-depth interviews conducted in Brussels, the paper provides insights on the impact of using mechanical systems in twelve newly renovated nearly- and net-zero energy households. The article calls for embracing thermal adaptation as a crucial design principle in future energy efficiency standards and codes. Results confirm the rebound effect in nearly zero energy buildings and the limitation of the current building energy efficiency standards. The paper offers a fresh perspective to the field of building energy efficiency that will appeal to researchers and architects, as well as policymakers.

scholarly journals Investigating the impacts of a changing climate on the risk of overheating and energy performance for a UK retirement village adapted to the nZEB standards

2019 ◽  
Vol 40 (4) ◽  
pp. 470-491 ◽  
Author(s):  
Radwa Salem ◽  
Ali Bahadori-Jahromi ◽  
Anastasia Mylona
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Energy Performance ◽  
High Energy ◽  
Climatic Conditions ◽  
Simulation Software ◽  
Mitigation Strategies ◽  
Zero Energy ◽  
Changing Climate ◽  
Retirement Village

The death toll of the 2003 heat wave in Europe exceeded 35,000 heat-related deaths. The elderly population were the most affected. The current paradigm within the construction industry in cold-dominant countries is to design/retrofit buildings with high levels of insulation. Whilst thermal comfort may be reached during colder months with this approach, the risk of overheating can be increased during hotter months. This paper aims to examine the impacts of a changing climate on the risk of overheating and energy performance for a UK retirement village. For this study, the buildings within the retirement village will be designed to reach the nearly zero energy building standard. Consequently, the risk of overheating of the buildings within the retirement village as they currently stand and as zero energy buildings will be investigated under current and future climatic conditions. The analysis is carried out using thermal analysis simulation software (TAS, Edsl). Combined heat and power and combined cooling, heat and power will be investigated as mitigating strategies with regard to overheating. The results of this study do not undermine the importance of continuing to improve the energy efficiency of existing buildings but rather highlight that the approach undertaken should be reconsidered. Practical application: Currently, there is emphasis placed on retrofitting and designing buildings, with high energy efficiency standards. Whilst this is in line with our vision as a society towards reaching a decarbonised, sustainable future, this work highlights that doing so, carries risks with regard to overheating. Nonetheless, the results demonstrate that with the incorporation of suitable mitigation strategies and adequate ventilation strategies, it is possible to achieve an energy efficient building that meets the heating and cooling demand (and thereby thermal comfort of occupants) during the heating and non-heating season.

scholarly journals The Comfort Map—A Possible Tool for Increasing Personal Comfort in Office Workplaces

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 233
Author(s):  
Ágnes Borsos ◽  
Erzsébet Szeréna Zoltán ◽  
Éva Pozsgai ◽  
Balázs Cakó ◽  
Gabriella Medvegy ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Environmental Quality ◽  
Considerable Effect ◽  
Comfort Level ◽  
Office Building ◽  
Indoor Environmental Quality ◽  
Visual Comfort ◽  
Acoustic Comfort ◽  
Open Plan ◽  
Office Employees

Previous studies have shown that indoor environmental quality (IEQ) parameters may have a considerable effect on office employees’ comfort, health and performance. Therefore, we initiated a research program to help occupants identify IEQ parameters they perceive as risk factors for their health in an office and enhance their comfort levels in an office environment. Since we assumed that office employees might have different indoor environmental quality expectations related to their work area and that these differences could be measured, our objective was to develop an office ‘comfort map’ based on occupants’ individual IEQ preferences. Thus, the goal of the comfort map would be to help tailor office spaces to their occupants’ health and comfort expectations. The comfort survey was developed to assess the comfort-related opinions of the occupants, based on IEQ parameters (visual comfort, acoustic comfort, air quality and thermal comfort) of a chosen open-plan office building. The survey also assessed the degree to which the given IEQ parameter was considered a health risk factor by occupants or caused a negative comfort sensation for them. The survey was filled in by 216 occupants. The answers were then analyzed with the help of a frequency table depicting relative frequency. The measurements of IEQ parameters took place in an open-plan office in the chosen office building (a Hungarian subsidiary’s office building belonging to an international company in Budapest). The occupants had different opinions regarding the perceived effects of the IEQ parameters on their health and comfort. Almost two-thirds of the respondents (64.8%) were dissatisfied with the adjustability of the noises and sounds IEQ parameter at their workstation. Furthermore, half of the respondents (50.1%) were dissatisfied with the adjustability of ventilation. Most of the occupants (45.8%) considered noises and sounds as the IEQ parameter that had a negative effect on their health. There were also IEQ differences between different areas of the office space. Based on these results, a comfort map was developed for the office. The comfort map contains information about the IEQ characteristics of each workstation by depicting the thermal comfort, carbon dioxide, visual comfort and acoustic comfort characteristics of a given workstation on a relative scale. Based on the thermal, air, acoustic, and lighting differences between the workstations, occupants can select their preferred workstations when a desk-sharing system works. Although still in its pilot phase, the comfort map could increase the chances for office employees to find the workstation best suited to their IEQ expectations. This could improve occupants’ overall comfort level, which could in turn enhance occupants’ productivity and mental as well as physical health.

scholarly journals Glass Curtain Wall Technology and Sustainability in Commercial Buildings in Auckland, New Zealand

2020 ◽  
Vol 7 (2) ◽  
pp. 57-65
Author(s):  
Yi Wu ◽  
Claire Flemmer
Keyword(s):  
Energy Efficiency ◽  
New Zealand ◽  
Thermal Comfort ◽  
Environmental Sustainability ◽  
High Energy ◽  
Building Envelope ◽  
Commercial Buildings ◽  
Continuous Heating ◽  
Curtain Wall ◽  
Glass Curtain Wall

Glass curtain wall provides an attractive building envelope, but it is generally regarded as unsustainable because of the high energy needed to maintain thermal comfort. This research explores the advances in the technology of glass cladding and the complex issues associated with judging its sustainability. It assesses the technology and sustainability of glass curtain wall on a sample of thirty commercial buildings in Auckland, New Zealand. Field observations of the glass-clad buildings, coupled with surveys of the building occupants and of glass cladding professionals are used to investigate the cladding characteristics, operational performance, sustainability aspects and future trends. The majority of the sample buildings are low-rise office buildings. The occupants like the aesthetics and indoor environment quality of their glass-clad buildings. However, continuous heating, ventilation and air conditioning are needed in order to maintain thermal comfort within the buildings and this has high energy consumption. The increasing use of unitized systems with double glazing instead of stick-built systems with single glazing improves the sustainability of the cladding through less material wastage and better energy efficiency. Inclusion of photovoltaic modules in the curtain wall also improves energy efficiency but it is currently too expensive for use in New Zealand. Environmental sustainability is also improved when factors such as climate, the orientation of glazed façades, solar control, ventilation and the interior building layout are considered. Any assessment of glass curtain wall sustainability needs to consider the economic and social aspects as well as the environmental aspects such as energy use

scholarly journals Microclimate and thermal comfort indices in silvopastoral systems under different planting directions and seasons

2020 ◽  
Vol 24 (4) ◽  
pp. 266-273
Author(s):  
Rafael P. de Carvalho ◽  
Debora M. Heid ◽  
Livia M. C. Davide ◽  
Ligia M. M. da S. Piletti ◽  
Fernanda L. F. de Jesus ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Block Design ◽  
Thermal Conditions ◽  
Radiant Heat ◽  
Control Treatment ◽  
Silvopastoral Systems ◽  
Randomized Block Design ◽  
Globe Temperature ◽  
East West ◽  
Comfort Indices

ABSTRACT The orientation of tree-rows in a silvopastoral system associated with different seasons of the year allows more or less sunlight penetration, resulting in deliberate modification of the microclimate composition and thermal conditions provided to animals. In this sense, the aims of this study were to evaluate microclimatic variables and thermal comfort indices for east-west and north-south oriented silvopastoral systems, compared to unshaded systems during summer and winter. The study was conducted at the Modelo II Farm (21° 08’ S 53° 17’ W) at an altitude of 354 m. A randomized block design in scheme of split-split plots with five repetitions was adopted. Two planting directions and a control treatment (unshaded) were evaluated in the plots. Collection times were evaluated in sub-plots, and the distance from eucalyptus trees was evaluated in sub-sub-plots. Changes in the east-west and north-south planting directions did not promote changes in climate variables, nor did they change the thermal comfort indices during summer. There were differences, however, in temperature and relative humidity of the air, black globe temperature, and radiant heat load during winter. Silvopastoral systems provide improvements in the environment and, concomitantly, to the thermal comfort of animals, when compared to unshaded systems. However, thermal stress situations occur despite the presence of trees, depending on the time of the day and the distance from the rows of eucalyptus trees.

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