Acceptable Level Of Thermal Comfort Research Articles

Development of energy efficient design proposals for air conditioned mosques: Temperate humid climate case

Mosques, which are types of religious buildings, are large buildings where many people pray at the same time. The diversity of the user type and density and the variability of the usage schedule make it difficult to establish the homogeneous thermal comfort of these large-volume public buildings. At the same time, the energy consumption in the buildings should be minimal in nowadays when the conventional energy sources decrease. The aim of this study is to evaluate created design strategies for designers and users in order to minimize energy consumption by determining the passive design criteria and choosing the type of air conditioning equipment while providing an acceptable thermal comfort level in mosques. According to the method created for the aim, the scenarios of mosques were compared in terms of thermal comfort and energy consumption in the temperate humid climate conditions. This method includes the analysis of scenarios created from the change of design parameters of mosques (plan, size, roof type of the mosques) with a simulation software which was validated with actual utility data. The suggestions were presented for the selection and design of the mechanical system as a result of the implementation of the created method. When the design scenarios of mosques are compared, the air conditioning of the indoor with radiant method consumed less energy than HVAC equipment with fan system. In accordance with the plan schemes (square, rectangle, circular), the least energy consumption per unit area was in the circular plan scheme and hemispherical design. Compared to the roof types (single dome, multi dome, pyramidal roof, flat roof), the most energy consumption per unit area was generally in the multi dome design. According to the average energy consumption values of the HVAC systems, there was 23 % less energy consumption in the flat plan type (105.06 kWh/m2) compared to the rectangular plan type (129.2 kWh/m2). In the intermittent use schedule of the HVAC system, 8 % more energy was consumed than in the continuous use schedule. According to the air changes per hour in the mosques, there was 5.93 % more energy consumption in 2 ach conditions compared to 0.5 ach conditions.

Techno-economic evaluation and environmental benefit of hybrid evaporative cooling system in hot-humid regions

Reducing the energy consumption of buildings is of great importance to achieve carbon neutrality targets. The air conditioning (AC) system in buildings, as a large energy consumer, should be taken into account as one of the main building service systems for energy saving integrated with energy-efficient and environmental-friendly technologies. Indirect evaporative cooler (IEC), constrained by its cooling principle, originally exerts energy saving potential in hot-arid regions. Recently, progress has been made in expanding its application to hot-humid regions. However, due to the large cooling load in hot-humid regions, an IEC-integrated hybrid system should be developed as an improved solution to effectively save energy and maintain the indoor thermal comfort. In view of the lack of a complete hybrid IEC system being reported thus far, in this study, the IEC is combined with a cooling coil unit as a primary air handling unit (IEC-PAU) for fresh air handling and supply. Accordingly, the model of the IEC-PAU with indoor fan coil units (FCUs) is constructed and incorporated into a typical office building, and the results are compared with a baseline case under hot-humid climate conditions. Comprehensive energy, economic, and environmental benefits are analyzed considering different setpoint temperatures in typical cities of the Great Bay area (GBA) of China. Results show that the proposed system could reduce the energy consumption of 4.6 kWh/m2 on average, with the acceptable thermal comfort level as they are in the reference cases. The greatest energy saving ratio is 8.3%, while the performance of the proposed system declines under the higher setpoint temperature. The saved electricity expenses can lead to the average discounted payback period of 8.2 years in the GBA cities. Furthermore, an annual greenhouse gas emission of 4.8 t on average can be diminished. In summary, this work demonstrates the feasibility of the hybrid IEC system as an effective approach for energy saving in hot-humid regions, which is promising to prompt the carbon neutrality in China.

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: <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.

Thermal performance of historic buildings in Mexico: An analysis of passive systems under the influence of climate change

The commitment to energy efficiency in buildings has become more relevant as a measure to mitigate the increase in temperature established by the Paris Climate Conference. This phenomenon has increased in historic buildings, which are not designed to maintain an acceptable level of thermal comfort for the occupants despite the recent increase in temperature, resulting in intensive energy use. This research evaluates the thermal performance of a passive cooling system in a historic religious building through a correlational method. The analysis included different occupancy levels and the climate model provided by the Intergovernmental Panel on Climate Change. The study considered meteorological data from the current scenario (2022) and two chronological progressions throughout the 21st century (2050, 2100). The meteorological database of future projections was collected by the Meteonorm software considering three climate change scenarios, specifically the Representative Concentration Pathways (RCP). The objective was to determine the effectiveness of the passive cooling system in mitigating climate change. The findings showed a reduction in radiative and conduction heat gains of 70 % in the current scenario and a decrease in temperature for the most unfavourable scenario (RCP 8.5 in 2100) between 1.4 °C and 1.9 °C. These results demonstrate the effectiveness of using efficient passive systems to mitigate climate change in temperate climates.

Prediction and optimization of thermal comfort, IAQ and energy consumption of typical air-conditioned rooms based on a hybrid prediction model

HVAC systems provide satisfactory indoor environments, but they usually consume large amounts of energy in order to achieve an acceptable thermal comfort level and indoor air quality (IAQ). Balancing thermal comfort, IAQ, and energy consumption is thus a challenging task. However, the main problem faced in such research is that it is inefficient to conduct traditional experiments or numerical simulation to obtain the optimal air supply parameters from a large number of variables. Therefore, the aim of this study is to develop a rapid prediction and optimization framework of IAQ, occupant comfort, and energy consumption. Firstly, Building Information Modeling (BIM) technology and Computational Fluid Dynamics (CFD) simulations are used to create the database containing indoor velocity, temperature and CO2 concentration for different distributions of occupants and ventilation parameters. Next, the extreme learning machine (ELM) model optimized by the grey wolf optimizer (GWO) algorithm is developed to predict the thermal comfort level and CO2 concentration, and the input parameters of the prediction models are interpolated to generate more cases. Finally, the satisfied air supply parameters for various optimization objectives are determined by combining the predicted PMV value and CO2 concentration with the energy consumption analysis. The results of the comprehensive analysis showed that the average concentration of CO2 after optimization is reduced and the |PMV|avg is reduced to less than 0.5, which is within acceptable limits. In addition, 14.34% energy saving is achieved in the illustrative example.

Downward piston ventilation assisted with a localized - Chair exhaust for mitigation of pathogen transport in educational spaces

This study proposes the integration of a localized - chair exhaust (LCE) device and a downward piston ventilation (DPV) in an educational space. The main aim is to assess the proposed system ability in providing a safe educational space similar to the case implementing the 2 m distancing between students at lower energy consumption. This allows the decrease of the DPV high supply flowrate without jeopardizing the protection level compared to the standalone DPV. A three-dimensional computational fluid dynamics (CFD) model of the educational space with DPV + LCE combination was developed as simulator software. The CFD model was validated experimentally and a parametric study was conducted to determine the best DPV supply airflow rate when assisted with LCE. The DPV flowrate should be capable of (i) preserving high protection levels, (ii) maintaining acceptable thermal comfort levels, while (iii) reducing the energy bill burden. Hence, an infected student was assumed sitting in the middle of the space and the exposure levels of the surrounding students were evaluated using the intake fraction (iF) index. It was found that for a practical use in educational spaces, the DPV system should be operated at 60 l/s per person with LCE at 20 l/s to maintain the high protection potential of the DPV system at 51% energy savings in the overall system energy consumption. Furthermore, the energy performance of the proposed system was compared to that of other ventilation systems implemented in educational spaces while offering same or better protection levels.

Numerical Design of a DSF System Subjected to Solar Energy and Applied in Building Occupied Spaces

A numerical design of a DSF (Double Skin Facade) system subjected to solar energy and applied to the heating of occupied spaces inside a building, in winter conditions, is presented in this study. The simulation is done using a building dynamic thermal response software to assess, among other parameters, the solar radiation incident on the DSF, the occupant thermal comfort level, indoor air quality level and thermal energy production. The occupant thermal comfort level is assessed by the Predicted Mean Vote index. The indoor air quality is assessed by the carbon dioxide concentration. The space considered in this study is an auditorium occupied by 210 people. The DSF system was installed on the south facade of this auditorium. The DSF system consists of 25 DSF. Each DSF consists of two surfaces, an opaque interior and a transparent exterior, separated by an air channel. This channel is used to heat the air that will be transported, through ducts, to the indoor HVAC (Heating, Ventilating and Air Conditioning) system, which is founded on a mixing ventilation system. The thermal energy produced in this way ensures an acceptable level of thermal comfort during most of the occupancy time and a level of indoor air quality close to acceptable. Therefore, it can be concluded that the HVAC system guarantees a good compromise between the thermal comfort of the occupants and the quality of the indoor air.

Determination of Optimum Envelope of Religious Buildings in Terms of Thermal Comfort and Energy Consumption: Mosque Cases

Mosques are quite different from other building types in terms of occupant type and usage schedule. For this reason, they should be evaluated differently from other building types in terms of thermal comfort and energy consumption. It is difficult and probably not even necessary to create homogeneous thermal comfort in mosques’ entire usage area, which has large volumes and various areas for different activities. Nevertheless, energy consumption should be at a minimum level. In order to ensure that mosques are minimally affected by outdoor climatic changes, the improvement of the properties of the building envelope should have the highest priority. These optimal properties of the building envelope have to be in line with thermal comfort in mosques. The proposed method will be a guide for designers and occupants in the design process of new mosques or the use of existing mosques. The effect of the thermal properties of the building envelope on energy consumption was investigated to ensure optimum energy consumption together with an acceptable thermal comfort level. For this purpose, a parametric simulation study of the mosques was conducted by varying optical and thermal properties of the building envelope for a temperature humid climate zone. The simulation results were analyzed and evaluated according to current standards, and an appropriate envelope was determined. The results show that thermal insulation improvements in the roof dome of buildings with a large volume contributed more to energy savings than in walls and foundations. The use of double or triple glazing in transparent areas is an issue that should be considered together with the solar energy gain factor. Additionally, an increasing thickness of thermal insulation in the building envelope contributed positively to energy savings. However, the energy savings rate decreased after a certain thickness. The proposed building envelope achieved a 33% energy savings compared to the base scenario.

How do paving and planting strategies affect microclimate conditions and thermal comfort in apartment complexes?

PurposeIn cities with high density, heat is often trapped between buildings which increases the frequency and intensity of heat events. Researchers have focused on developing strategies to mitigate the negative impacts of heat in cities. Adopting green infrastructure and cooling pavements are some of the many ways to promote thermal comfort against heat. The purpose of this study is to improve microclimate conditions and thermal comfort levels in high-density living conditions in Seoul, South Korea.Design/methodology/approachThis study compares six design alternatives of an apartment complex with different paving and planting systems. It also examines the thermal outcome of the alternatives under normal and extreme heat conditions to suggest strategies to secure acceptable thermal comfort levels for the inhabitants. Each alternative is analyzed using ENVI-met, a software program that simulates microclimate conditions and thermal comfort features based on relationships among buildings, vegetation and pavements.FindingsThe results indicate that grass paving was more effective than stone paving in lowering air temperature and improving thermal comfort at the near-surface level. Coniferous trees were found to be more effective than broadleaf trees in reducing temperature. Thermal comfort levels were most improved when coniferous trees were planted in paired settings.Practical implicationsLandscape elements show promise for the improvement of thermal conditions because it is much easier to redesign landscape elements, such as paving or planting, than to change fixed urban elements like buildings and roads. The results identified the potential of landscape design for improving microclimate and thermal comfort in urban residential complexes.Originality/valueThe results contribute to the literature by examining the effect of tree species and layout on thermal comfort levels, which has been rarely investigated in previous studies.

Hybrid cooling system integrating PCM-desiccant dehumidification and personal evaporative cooling for hot and humid climates

Hot and humid climates present a challenge for implementing passive cooling practices in office spaces, due to the inherent small temperature difference between day and night, which affects the utilization of thermal storage systems. Moreover, added means are required to maintain the humidity in the space at an acceptable level for comfort. The novelty of this study is to design and implement a feasible hybrid cooling system for office spaces in such climates by uniquely combining several sustainable cooling, thermal storage, and dehumidification solutions. The proposed system integrates a phase change material (PCM) thermal storage layer with a melting temperature of 25 °C to cool the supply air and a personalized evaporative cooler (PEC) to provide cooling for the occupants. The supply air humidity is controlled using a solid desiccant wheel regenerated via an auxiliary heater assisted with a Trombe wall. Mathematical models were adopted for each system component/process, solved numerically and integrated to size the system components, simulate their operation and predict the overall system's performance in an office space during the summer months of Beirut climate. The proposed system was found to achieve acceptable thermal comfort levels in the space. Moreover, it reduced the total energy cost by 87% compared with a conventional air conditioning unit over the summer period. In addition, the Trombe wall provided energy savings of 55% compared to relying only on the auxiliary heater. Hence, integrating several sustainable solutions succeeded in implementing an effective cooling system of office spaces in hot humid climates.

Evaluation of Thermal and Energy Performance in Mosque Buildings for Current Situation (Simulation Study) in Mountainous Climate of Abha City

Achieving and maintaining indoor thermal comfort is a crucial factor for energy saving and human health, especially in heavily occupied public buildings, such as mosque buildings. The acceptable level of thermal comfort should not be achieved at the expense of damaging the environment by using preventable energy depletion. This study aims to investigate what level thermal comfort is achieved and related issues in mosque buildings in Abha city, which has a semi-arid moderate/cold mountainous climate. The research involved a computer modelling investigation by using Thermal Analysis Software (TAS). A number of comparisons of the simulation results with actual measurement data in mosque buildings, such as temperature, relative humidity, and energy demand were conducted. Main factors influencing thermal comfort and PMV were investigated for the selected mosques. In addition, thermal performance of mosques’ fabrics and envelopes in terms of solar gain and heat loss/gain by conduction and its impacts on thermal comfort and energy demands were also discussed. The outcome showed some discomfort due to heat gain in summer and heat loss in winter. The results also revealed that the main factors behind heat gain or loss were the poor quality of the investigated mosque buildings’ envelopes, including walls, roofs, floors, windows, and doors.

Evaluating the perception of thermal environment in naturally ventilated schools in a warm and humid climate in Nigeria

Field study was conducted in naturally ventilated primary school buildings in a warm and humid environment in Imo State, Nigeria to determine the thermal comfort perception of young children (aged 7–12 years) and to understand the thermal conditions in the classrooms. The comfort temperature was investigated in two types of classroom buildings during the rainy and dry seasons from October 2017 to May 2018. Approximately 7050 completed valid questionnaires were collected from 330 young children repeatedly surveyed twice a day. The children answered comfort questions at the same time the indoor and outdoor thermal variables were being measured. Results indicated that the combined ‘open-space’ classrooms produced a neutral temperature of 28.8°C with comfort range, 25.2–32.3°C. The neutral temperature of the combined ‘enclosed-plan’ classrooms is 28.1°C with 25.8–30.5°C as the comfort range. The differences in the comfort perceptions may be attributed to the differences in the architectural characteristics of both categories of classroom buildings. High temperature tolerance was shown by the participating children in the study area. This article, therefore, suggests that installing air conditioning in primary schools in the warm humid environment in Nigeria may not be necessary as it could lead to unnecessary energy consumption and carbon emission. Practical application: This work is part of the main research work that pioneers research on thermal comfort in public primary school classrooms in Nigeria. The findings from this study on the acceptable indoor temperatures in naturally ventilated classrooms in the warm and humid climate in Nigeria are important information for building services engineers and architects. The young children in these classrooms can accept high indoor temperatures. The intention of this information is to discourage high energy usage in heating, ventilation and air-conditioning (HVAC) system in primary school buildings in the study area, while maintaining the acceptable thermal comfort levels.

Evaluation of Thermal Comfort in the Traditional Bourgeoisie Houses in Beirut

The increasing of energy demands has considerably increased the requirements for new and traditional buildings in different climate zones. Unprecedented heat waves have increased climate temperature, in particular, in moderate climate zones such as Lebanon. In Beirut, only the residential sector consumes 50% of total electricity consumption. HVAC (Heating, Ventilation and Air conditioning) systems are used to reach acceptable thermal comfort levels in the new residential buildings. In case of the traditional bourgeoisie houses in Beirut, there are no discussions about the use of HVAC systems to achieve the required thermal comfort level. Thus, to reach an acceptable thermal comfort level, these houses which already contain natural ventilation system shall adapt the modern thermal comfort requirements and thermal comfort strategies and technologies where their architectural features and existing materials condition the available solutions. In order to identify the best options within the possible intervention lines (envelopes, passive strategies, equipment, renewable energy systems), it is necessary to perceive the real performance of this type of houses. In this context, the article presents the results of the study of thermal performance and comfort in a three case studies located in Beirut. Detailed field data records collected are analyzed, with a view to identify the indoor thermal environment with respect to outdoor thermal environment in different seasons. Monitoring also included measurement of hygrothermal parameters and surveys of occupant thermal sensation.

Determination of thermal comfort of religious buildings by measurement and survey methods: Examples of mosques in a temperate-humid climate

Thermal comfort in buildings is an important parameter affecting the physiological and psychological conditions of the users as well as their working efficiency and activity levels. Acceptable thermal comfort levels specified in the standards are created within certain limits. This raises the question whether it is appropriate to use the same acceptable comfort ranges in different building types and climatic conditions. In this study, the design-usage of the example mosques in temperate-humid climate was evaluated by using thermal comfort level measurements and survey methods. The aim of this study is to compare the indoor thermal comfort conditions measured in mosques according to standards, to determine the thermal comfort perception of the users, to evaluate the difference between the measured and perceived thermal comfort levels. In the scope of the study, two mosques with different heating and cooling systems were measured with thermal comfort devices. The thermal sensation survey was conducted with the users on Fridays of the measurement weeks. When the thermal comfort levels that measured and perceived were compared, the indoor conditions were within acceptable ranges according to the measured results whereas the user thermal sensation survey results revealed that the environment was hotter. In order to create similar thermal comfort in the interior, it was determined that design innovations or mechanical solutions should be made for the prayer zones in the entrance areas of the mosques. In light of the findings, suggestions were made for the design of the new mosques and the usage program of the existing ones.

Energy Performance Comparison between Two Liquid Desiccant and Evaporative Cooling-Assisted Air Conditioning Systems

This study investigated the annual energy saving potential and system performance of two different evaporative cooling-based liquid desiccant and evaporative cooling-assisted air conditioning systems. One system used an indirect and direct evaporative cooler with a two-stage package to match the target supply air point. The other was equipped with a single-stage, packaged dew-point evaporative cooler that used a portion of the process air, which had been dehumidified in advance. Systems installed with the two evaporative coolers were compared to determine which one was more energy efficient and which one could provide better thermal comfort for building occupants in a given climate zone, using detailed simulation data. The detailed energy consumption data of these two systems were estimated using an engineering equation solver with each component model. The results showed that the liquid desiccant and dew-point evaporative-cooler-assisted 100% outdoor air system (LDEOAS) resulted in approximately 34% more annual primary energy consumption than that of the liquid desiccant and the indirect and direct evaporative-cooler-assisted 100% outdoor air system (LDIDECOAS). However, the LDEOAS could provide drier and cooler supply air, compared with the LDIDECOAS. In conclusion, LDIDECOAS has a higher energy saving potential than LDEOAS, with an acceptable level of thermal comfort.

Comparative Study of Building Envelope Cooling Loads in Al-Amarah City, Iraq

In recent years, the summer season in Iraq has become longer and hotter than before, leading to high cooling loads inside buildings and increased demand for electrical energy. The use of sustainable energy and insulation techniques for building envelopes are reasonable solutions for overcoming harsh weather conditions and reaching acceptable thermal comfort levels. In this study, a survey on more than 60 residential buildings in Al-Amarah City, Iraq, was conducted on 21 July 2018 to examine the nature of the most common construction materials used in the building envelopes. Furthermore, the cooling loads of building envelope elements, e.g. roof, external walls and windows, was calculated using the cooling load temperature difference/solar cooling load/cooling load factor method of ASHRAE. The results were tabulated and compared for each combination of elements. The results showed that reflective glass is the optimal choice for exterior windows. The 'clay"“insulation"“fired clay bricks"“cement mortar' and 'cement mortar"“thermo-stone bricks"“cement mortar"“gypsum mortar' combination layers performed well for roof and external wall installations, respectively. Several recommendations were deduced from this study, which can be used as guidelines for construction authorities in Al-Amarah City and individuals interested in energy-efficient buildings.

End-users’ and policymakers’ impacts on optimal characteristics of a dew-point cooler

Impacts of end-users’ behavior and policymakers’ decision on the optimal performance characteristics of a dew point cooler are investigated. Acceptable level of thermal comfort, cooling load, and the economic factors, including water and electricity tariffs, and inflation and discount rates, are considered as the effective parameters. The objective functions of the conducted multi-objective optimization, i.e., life-cycle cost, annual water consumption, and annual average coefficient of performance, in addition to the charge paid for the resource consumption throughout the first year are studied as the performance criteria. A benchmark residential building in Ahmedabad, India, is also selected as the case study. Results show that despite paying coefficient of determination penalty, the value of 15% for the maximum allowable predicted percentage dissatisfied is the best thermal comfort level from both economic and resource consumption perspectives. Moreover, in the investigated range of the inflation rate, the four introduced performance criteria change 5.4%, 51.6%, 45.6%, and 33.4% while the corresponding values for discount rate are 10.1%, 58.1%, 84.5%, and 37.1%, respectively. Therefore, performance of the optimum system is more sensitive to the discount rate.

Evaluation of thermal comfort in building transitional spaces - Field studies in Cardiff, UK

Transitional spaces have been widely applied in building designs. They may account for 10–40% of total volume in different types of buildings. Maintaining an acceptable level of thermal comfort for transitional spaces poses challenges to building designers and engineers. However, there is not in general a recommended acceptable comfort range for transitional spaces, nor are there specific thermal comfort prediction methods. This paper aims to investigate the thermal environmental performance and people's adaptive comfort in transitional spaces, by conducting field studies, which include on-site questionnaire surveys and physical measurements. Field studies were carried out for three selected case study buildings in Cardiff, each having some forms of transitional space. They were the National Assembly for Wales Senedd, the Hadyn Ellis Building and the Royal Welsh College of Music and Drama. The total responses from the questionnaire surveys were 736 and 580, for all buildings, during the summer period in 2017 and the winter period in 2018 respectively. This paper first presents the findings from the field studies, followed by in-depth analysis of human adaptability to thermal environment. Strong correlations were identified between clothing value and indoor operative temperature. People's adaptability to the thermal environment is confirmed, with nearly 80% of the respondents opting for self-adaptive actions to overcome uncomfortable situations. The identified 90% acceptability comfort band (−0.5 < TSV< +0.5) were 4.0 °C and 4.2 °C for the summer period and the winter period respectively, implying that a fine control of the indoor temperature to maintain an acceptable comfort level is not necessary.

Demand response of space heating using model predictive control in an educational office building

The building sector plays a remarkable role in decreasing of the overall global CO2 emissions since as much as 30% from the total global CO2 emission are generated in buildings. Demand response provides one possibility to tackle the problem. It can be used to decrease CO2 emissions in entire energy system in addition to providing energy cost savings for building owners and energy companies. In this study, the demand response potential was estimated in an educational office building that was heated by district heating. The potential was defined in respect of energy cost savings, energy flexibility and thermal comfort. Model predictive control was developed, which utilized the dynamic hourly district heating prices. The MPC algorithm written in the Matlab software, predicted the future heating demand while the optimization algorithm NSGA-II minimized the heating energy cost, maximized the energy flexibility and maintained acceptable thermal comfort by changing the space heating temperature setpoints. The operation of the MPC algorithm was tested in the IDA ICE 4.8 simulation software. As a result, the annual district heating energy costs could be reduced by 4.2% compared to the reference case with constant space heating temperature setpoint of 21 °C. The maximum flexibility factor attained was 14%. Acceptable level of thermal comfort was maintained throughout the simulation time.

Modelling development and analysis on the Balanced Energy Networks (BEN) in London

In the UK up to 40% of total final energy use is accounted for by the heating and hot water systems, which makes up 20% of greenhouse gas emissions. One path to low carbon heating is to electrify heat, and then meet the electricity demand via a smarter grid. This article presents a novel approach to electrifying heat based on a balanced energy network (BEN) system located at the London South Bank University (LSBU) campus. The BEN system includes borehole thermal storage, an ambient temperature heat network (heat transmission and distribution), water source heat pumps, smart hot water storage, and demand side response (DSR) service. Its thermal and electrical energy performances were mainly investigated. A novel energy performance index (TSE: total system efficiency) was also proposed and applied in assessing the performances. Several key findings were achieved as follows: (1) The TSE varied from 1.4 to 2.2 in one of the coldest months of the year, indicating a great improvement on energy efficiency. (2) The ICAX high-temperature heat pumps in BEN operate with a higher COP fluctuating between 3.1 and 3.2 with a Carnot efficiency of 0.5. (3) With an acceptable level of thermal comfort, the BEN system can reduce CO2 emissions up to 3.62 t for two weeks. (4) Corresponding with the initial design setting, 70 °C has been proved as the optimal operating output temperature of heat pump.