Thermal Performance Of Residential Buildings Research Articles

Mechanical Ventilation Heat Recovery Modelling for AccuRate Home—A Benchmark Tool for Whole House Energy Rating in Australia

To manage energy-efficient indoor air quality, mechanical ventilation with a heat recovery system provides an effective measure to remove extra moisture and air contaminants, especially in bathrooms. Previous studies reveal that heat recovery technology can reduce energy consumption, and its calculation needs detailed information on the thermal performance of exhaust air. However, there are few studies on the thermal performance of bathroom exhaust air during and after showers. This study proposed a detailed thermal performance prediction model for bathroom exhaust air based on the coupled heat and mass transfer theory. The proposed model was implemented into the AccuRate Home engine to estimate the thermal performance of residential buildings with heat recovery systems. The time variation of the water film temperature and thickness on the bathroom floor can be estimated by the proposed model, which is helpful in determining whether the water has completely evaporated. Simulation results show that changing the airflow rate in the bathroom has little effect on drying the wet floor without additional heating. The additional air heater installed in the bathroom can improve floor water evaporation efficiency by 24.7% under an airflow rate of 507.6 m3/h. It also demonstrates that heat recovery can significantly decrease the building energy demand with the fresh air load increasing and contribute about 0.6 stars improvement for the houses in Hobart (heating-dominated region). It may be reduced by around 3.3 MJ/(m2·year) for the houses in other regions. With this study, guidelines for optimizing the control strategy of the dehumidification process are put forward.

Impact assessment of climate change on energy performance and thermal load of residential buildings in New Zealand

While it is evident that climate change will have an impact on the energy demand for heating and cooling in buildings, the exact extent of this impact is not yet fully understood. Quantification of future cooling and heating need in buildings provides a basis for taking appropriate measures for building climate change adaptation. The focus of this study is to examine how future climate change scenarios will impact the heating and cooling of residential buildings across different climatic regions in New Zealand. The future weather data under changing climate were generated for six climatic zones of New Zealand employing the statistical downscaling method. The study used various climate change scenarios, which represent concentration pathways (RCPs), to generate weather data. Specifically, the RCP8.5 and RCP4.5 scenarios were employed in the building performance simulations for different prototypes of residential buildings. The results showed there would be a significant change in the thermal performance of residential buildings, with a noticeable increase in cooling load and a decrease in heating load. These changes include a maximum thermal load change of 3 kWh/m2 in Auckland by 2090, 2.7 kWh/m2 in Hamilton, 8.3 kWh/m2 in Wellington, 4.2 kWh/m2 in Rotorua, 11 kWh/m2 in Christchurch, and 11.6 kWh/m2 in Queenstown. The warmer climatic zones are expected to change from a heating dominated to a cooling-dominated zone. The results indicated the importance of considering present and future climatic conditions in design and establishing a foundation for actions for the resilience of buildings to climate change.

Analysis of Thermal Performance of Naturally Ventilated Residential Building in Tropical Climate: Case Study of Phnom Penh, Cambodia

Comfort of the building is one of the important factors that is hard to achieve for architects and engineers as it depends on both physic and psychological parameter. This paper discusses these two aspects on the thermal performance of residential building in context of hothumid climate. Three different types of residential buildings including townhouse, detached house and apartment building in Phnom Penh, Cambodia were chosen as the case studies. The analysis of thermal performance of each house is based on (a) the measurement of physical parameters (air temperature, relative humidity, air velocity), (b) occupants survey to compare with data from the measurement and (c) interview with the occupants to know about their satisfaction and sensation to the physical parameters. Impact of different designs of houses on thermal performance and the importance of influential physical parameters for tropical climate is analysed. Comparison of results to the Fanger’s model also indicate the importance of air velocity in thermal comfort for tropical region. The survey shows that in natural ventilation, women in their 20s to 30s feel comfortable with the temperature of 29 to 30°C and humidity of 73 to 75%.

A thermal performance standard for residential buildings in warm climates: Lessons learned in Brazil

This paper presents the main challenges faced and lessons learned when developing a new method to assess the thermal performance of residential buildings for the recently updated Brazilian building performance standard, NBR 15575–1:2021. It touches on subjects related to the representation of occupant behavior, climate, and thermal acceptability in building performance simulation, as well as the use of reference models, key performance indicators, and performance levels in policies. NBR15575 provides a thorough procedure to analyze thermal performance, allowing buildings to be assessed while in passive operation mode and also accounting for energy needs when active operation is necessary. Multiple key performance indicators are introduced to provide a comprehensive evaluation. The main difficulty found was dealing with diversity. Given the vast scale of Brazil’s territory, a high variation in culture, climate and construction techniques is expected, thus requiring a compromise between detail and scalability. There are still many opportunities for improvement, especially regarding the representation of occupants, and adjustments of the characteristics of reference models to promote high thermal performance, considering the diverse climates, regional practices, and economic needs. This paper might help researchers and other stakeholders to develop and improve other local standards and protocols, especially for warm climates.

Sensor specifications for in-situ measurement of the temperature distribution inside the wall material for evaluating thermal performance of residential buildings

It is important to measure and ensure the thermal insulation performance of newly built or existing residential buildings to promote energy-efficient and comfortable housing throughout society. Among various in-situ measurement methods for this purpose, this study focuses on the probe insertion method, in which a borescope and a temperature sensor are inserted through a tiny hole drilled in the interior side of the wall to visually inspect and measure the temperature distribution inside the wall. In this method, the temperature sensor itself can act as a thermal bridge, which causes a deviation from the original temperature distribution inside the insulation material. In this paper, based on physical considerations and heat conduction simulation, we introduce two dominant dimensionless numbers that determine the temperature deviation: the Biot number and the newly defined Nc value. In addition, we draw schematic charts to find the temperature deviation from the introduced dimensionless numbers, and suggest a procedure to determine the required specifications of a temperature sensor that can accurately measure the temperature distribution.

The influence of envelopes in the thermal performance of residential buildings, from the perspective of bioclimatic architecture

Energy efficiency measures (EEMs) and their impact on the thermal performance of buildings as well as on the user's thermal comfort, have become the focus of several studies. Bioclimatic strategies can contribute to improving thermal performance while increasing indoor thermal comfort for users. This paper aims to verify the bioclimatic potential of two types of dwellings in three Brazilian cities. The first one is the baseline, with basic construction systems. The other includes EEMs. The method consists of the verification of bioclimatic potential by psychometric charts for indoor and outdoor conditions. The results show significant indoor discomfort caused by heat in both dwellings—thermal comfort conditions during more than 95% of annual hours in Manaus, and during 85% in São Paulo. Therefore, energy efficiency strategies such as shading, ventilation and HVAC systems are necessary to promote thermal comfort conditions in hot climates.

Passive Cooling Strategies for Improving Thermal Performance of Residential Buildings in Naya Raipur, Chhattisgarh

Passive Cooling Strategies for Improving Thermal Performance of Residential Buildings in Naya Raipur, Chhattisgarh

BIM-Based Energy Analysis and Sustainability Assessment—Application to Portuguese Buildings

Buildings are responsible for several negative impacts on the environment, most of them related to nonrenewable energy consumption, increasing the concern regarding buildings energy efficiency. In this context, computer software has been used to estimate the energy needs of the built environment, and the Building Information Modelling (BIM) methodology can be used to simplify this process. This study aims to validate a BIM-based framework to streamline the energy analysis of Portuguese buildings, based on the method of the national regulation for the thermal performance of residential buildings. Currently, designers need to spend considerable time assessing all the building characteristics and performing the mandatory calculations for energy performance analysis. It is also intended to link the results of the energy simulation with a Building Sustainability Assessment method—SBToolPT-H. The purpose is to demonstrate how it is possible to benefit from this approach to simultaneously improve building sustainability during the design stage. To do so, different case studies were modelled in Autodesk Revit and exported to a BIM energy tool to perform energy simulation analysis. The results were validated against the official assessment method of the Portuguese thermal regulation and were successfully used to assess the SBToolPT-H energy efficiency category. The research outcomes provide design teams with a reliable BIM-based framework to improve building energy performance and to develop thermal projects while enhancing building sustainability. It also increases the knowledge about the integration of sustainability assessment in the BIM environment, providing new insights for complete integration.

Effect of Phase Change Materials on the Thermal Performance of Residential Building Located in Different Cities of a Tropical Rainforest Climate Zone

This study aims to investigate the thermal performance of PCM and PCM combined with nighttime natural (NV) and mechanical ventilation (MV) applied to a residential building located in eight cities of tropical rainforest climate zone (Af). The analysis was accomplished using numerical simulations and developing a unique methodology for selecting the PCM melting temperature based on the thermal comfort limits. The thermal performance of the PCM integrated building was quantitatively evaluated using the concept of peak temperature drop. Additionally, a novel indicator of Total Temperature Drop (TTD) was introduced to determine the overall impact of the PCM and PCM combined with NV/MV on the thermal comfort conditions inside the building. The results showed that PCM 28 was the most efficient in improving the thermal performance of the building located in the Af climate zone, achieving a TTD of up to 356 °C per year. The usage of PCM 28 combined with nighttime natural ventilation improved the TTD values by up to 15%, whereas the integration of PCM 28 combined with mechanical ventilation resulted in a TTD values increase of up to 45%. Conclusively, mechanical ventilation showed its superiority over natural ventilation in the tropical rainforest climate, and PCM 28 applied together with mechanical ventilation could be used as the optimum combination for the whole climate zone.

Window to wall ratio and orientation effects on thermal performance of residential building: A case of Butwal Sub-Metropolis

The orientation and glazed surface area used for windows in a building have significant effects on its indoor thermal comfort and overall energy consumption. The increasing use of glazed windows and lack of consideration of orientation in building design have become a major problem in warm and humid regions as windows cover sensitive skin areas for the exchange of energy leading to increased solar gain inside the building. This paper describes the effect of the varied ‘area ratio of glazed window to the wall for different building orientations’ on the thermal performance of the residential building in a warm humid climatic region of Nepal. A typical residential building located in Kalikanagr of Butwal, the fast-urbanizing sub-metropolis of Western Nepal, was selected for the study from 18 houses surveyed using the purposive sampling method. Nine varying values of Window to Wall Ratio (WWR) of glazed façade ranging from 0.1 to 0.9 with a constant increment of 0.1 in north and south façades, and the change in the building orientations were considered for the detailed study. Altogether eighty different test scenarios including base case scenarios were created and annual thermal energy consumption was computed for each test scenario using the Autodesk Ecotect Analysis, 2011. Findings from the study showed that the south orientation is the most appropriate compared to the north-east for all WWR to reduce the building energy consumption and an increase in WWR also results in increased energy consumption. The study concludes the careful considerations of WWR and the south orientation during the designing of building will contribute to efficient energy consumption in residential buildings.

Thermal performance of residential building with mixed-mode and passive cooling strategies: The Brazilian context

The definition of user behavior in computer simulations for building thermal performance analysis is a challenging and complex task. People behave differently depending on their routine and culture, among many other factors. Thus, in this study, mixed-mode climatization for cooling and heating (air conditioning and natural ventilation) was analyzed considering different thermal performance indicators, construction systems and climates in Brazil. The typology analyzed was a single-family dwelling. The results showed not only how different cooling strategies can change the dwelling thermal performance, but also how this performance may be perceived differently based on the indicator. Depending on the indicator, distinct envelopes would be recommended. Also, the study demonstrated that for public policies, the stakeholders need to understand the behavior and occupancy patterns of residents who are representative of a country in order to identify, with more accuracy, the most appropriate envelope for each case. In the case of the indicators, metrics that are most easily adapted to considerer resilient according to climate changing are recommended for inclusion in standards and regulations.

The Impacts of Building Regulations on the Thermal Performance and Energy Consumption of Residential Buildings in Riyadh City-Saudi Arabia

Riyadh city is the fastest growing city in Saudi Arabia. The rapid urban growth that happened recently in Riyadh was not based on the traditional urban planning principles, which have been established and applied for the city development process. The imported building regulations have created a new urban structures and street patterns. The contemporary urban form in Riyadh city is based mainly on traffic and economic consideration with the neglect of environmental dimensions. This research aims to examine the impacts of building regulations on the thermal performance of residential buildings in Riyadh city, with the ultimate goal of establishing planning guidelines that consider the environmental conditions of the city. The methodology adopted for achieving the aim of this study consists of two phases. First, the literature related to building regulations development in Riyadh, as of 2018, was reviewed. Second, buildings energy simulation was conducted to examine the thermal performance of the typical current status of residential building blocks in Riyadh city, and then several changes to building regulations were made to investigate their impacts on the thermal performance of buildings. The results showed that the impacts of Riyadh building regulations on the thermal performance of residential buildings differ across the evaluated cases. The ratio of building height to street width, urban block street orientation, and building orientation are the main factors affecting thermal performance of buildings within urban block. The study also concludes that adjusting the ratio of building height to the distance between buildings could have a significant impact in reducing cooling loads. This study will help policy makers, planners and designers to investigate the shortcoming in the current building regulations.

Investigating Thermal Performance of Residential Buildings in Marmari Region, South Evia, Greece

In recent decades, the steady increase of energy consumption from building construction and operations cause atmospheric pollution and significant financial burden, mainly due to the high costs imposed from energy production. This study examines ways under which modern designs of a building can be applied on construction and domestication while following conventional methods of construction, compared to a building that has been constructed and domesticated under bioclimatic architecture. Particularly, two buildings were investigated in terms of the energy consumption incurred, being built on the same seaside area and period of construction and at adjacent plots of the same distance from sea for ease of comparison. The first building (A1) was constructed under the principles of bioclimatic architecture, being also facilitated with green and smart technologies. The second building (A2) was constructed under conventional construction techniques. The energy efficiency of both buildings was calculated by the “TEE KENAK” software, while specific parameters were recorded. Energy classifications of both buildings were valued and a proposed scenario and interventions unveiled the energy classification upgrading from A2 to A1. Our analysis revealed, as also found in the literature, that during thermal energy oscillating conditions, corresponding relative humidity stresses were observed, indicating that the vapor pressure handling should be taken into account towards comfort. The preliminary incremental cost evaluation and comparison of A1 and A2 energy upgrading under the criterion of simple payback period were critically discussed.

Passive cooling strategies in roof design to improve the residential building thermal performance in tropical region

Residential sector represents an important part, almost one-third of total Indonesian energy demand. The literature survey showed that the cooling and lighting systems are the largest energy consumers in this residential sector. The aim of the present paper is to evaluate the effectiveness of suitable passive cooling strategies on roof level to reduce the building energy demand on equatorial hot-humid climate region. The feedback of previous researchers have identified that the main influencing factors on building thermal comfort are the building roof design and ventilation system. In the present study, the effectiveness of three passive cooling techniques on roof level, cool roof coating, thermal insulation on ceiling and natural air ventilation on attic zone, is studied to improve thermal performance of Indonesian residential buildings. Results showed that the simultaneous implementation of these passive cooling techniques is able to significantly reduce the temperature overheating and thermal discomfort by 37.3% in tropical region.

Stepwise calibration for residential building thermal performance model using hourly heat consumption data

Model calibration plays an important role in reducing the discrepancy between the simulation value and the measured data. The calibrated building thermal performance model will better guide the building retrofit and optimized operation. At present, however, researchers often calibrate building thermal performance model based on monthly data, and there are a few studies on hourly model calibration. In this paper, a stepwise calibration method for residential building thermal performance model based on hourly heat consumption data is proposed. This method mainly includes the following two key steps: (1) Sensitivity analysis. Morris sensitivity analysis method is adopted to reduce the number of calibrated parameters and improve the efficiency of model calibration. (2) Stepwise calibration. The building thermal parameters and the occupant behavior related parameters are distinguished, and proposing a calibration method for the schedule of occupant behavior related parameters. The effects of different processing methods for occupant behavior related parameters on the accuracy of calibration results are analyzed. A case study is demonstrated in a residential building with satisfying results. The Morris sensitivity analysis method reduces the number of calibrated parameters from 14 to 6. On the basis of the calibration for building thermal parameter, three calibration schemes for different occupant behavior related parameters are compared. Compared with before calibration, the MBE and CV(RMSE) of the best calibration scheme are reduced from −81.71% and 83.89% to −2.91% and 15.90%. The results meet the limits of model calibration accuracy in ASHRAE Guideline 14, IPMVP and FEMP standards.

The effect of window opening ventilation control on residential building energy consumption

Occupant behavior in terms of the operation of natural ventilation is a significant parameter that affects the thermal performance of residential buildings. The objective of this study was to evaluate the influence of the occupant behavior regarding the window opening ventilation control and the building thermal mass on the energy consumption related to HVAC system in residential buildings in Brazil. The focus of the study was on analysing different natural ventilation operation scenarios: morning to night ventilation, automated ventilation control, and night ventilation. The combined use of a HVAC system and natural ventilation was applied using an Energy Management System that enables advanced controls during simulation in the EnergyPlus program. The results indicate that buildings with medium thermal capacity have a greater potential to provide thermal comfort for users, since using an appropriate building ventilation control. Also, appropriate building ventilation achieved through automated ventilation control combined with medium thermal inertia provided a reduction in the energy consumption for HVAC system.

Envelope Thermal Design Optimization for Urban Residential Buildings in Malawi

This study sought to optimize the envelope thermal design of free-running urban residential buildings in Malawi. It specifically set out to improve the urban residential buildings’ thermal comfort and suggest optimal envelope thermal design features for these buildings. The research study was primarily dependent on computer simulations in EnergyPlus to replicate the typical Malawian urban residential building’s thermal behaviour and then study the impacts of various envelope configurations on the thermal comfort conditions registered in the building. The simulation model was experimentally validated to check its appropriateness to the climatic design conditions prevalent in Malawi and out of the three major cities that were considered, the model was found to be appropriate for use in the two cities of Mzuzu and Lilongwe leaving out the city of Blantyre. The optimization methodology that was employed involved the use of orthogonal arrays, statistical analyses and the listing method. It was found that the optimal envelope thermal design, which registered up to 18% lower discomfort hours than that of the typical urban residential building, consists of a 50 mm concrete floor slab, 230 mm burnt brick walls with an external layer of 19 mm EPS, tiled roof with an internal layer of sarking and 50 mm EPS, double Low-E Glazing with a transparency ratio of 45% and 0.2408 m2 of adaptable operational surface area for the air bricks. Out of all the envelope features that were studied, air infiltration registered the most significant contribution towards the ultimate residential building thermal performance. It was demonstrated that controlled air infiltration through the use of operable air bricks whose operational surface area is adaptable can be very effective in enhancing the building’s comfort levels. It was further observed that excessive insulation of the building envelope generally has a detrimental effect on the indoor space thermal comfort levels.

Estimating thermal performance and energy saving potential of residential buildings using utility bills

The objective of this study is to provide a practical method for estimating the energy saving potential of residential buildings using utility bills that are relatively easy to obtain from occupied buildings. The building characteristics and utility bills for three years, 2009–2011, were sampled from 128 apartment complexes, including 52,731 individual housing units. The utility billing data contain the monthly energy use of electricity, natural gas, and district heat for each complex. The energy uses of each complex were characterized using change-point linear regression models which described energy use as a function of monthly outdoor temperature and statistical parameters. The change-point models are statistically well fitted with actual monthly energy use, and the parameters of the models are capable of characterizing the energy use of residential buildings with hydronic radiant floor heating equipment. From the results, significant opportunities for space heating energy saving are identified in the sample complexes. The most sensitive and informative parameter for space heating energy saving is heating slope. The heating slope can represent the heat loss from the envelope and the efficiency of space heating. The method developed in this study can help to quantify the thermal performance of residential buildings, and also to identify the best type of energy efficiency opportunity.

The Bio-Climatic Analysis and Thermal Performance of Residential Building in Upper Egypt A Case Study, “East El-Owauinat Region”

ABSTRACTAs a result of the change and development of Egyptian society, Egyptian governmenthas focused its attention of comprehensive development to various directio ns. One of theseattentions is housing, construction and land reclamation in Upper Egypt to go out from thenarrow valley which is about 5% of Egypt area. East El- Owauinat is one of these areas. It isan agriculture project and must be valid all the facto rs needed for sustainability. East El -Owauinat region is located at 220 28` N latitude and 280 42` E longitude. The climate of thisregion is caricaturized by; aridity, high summer daytime temperature, large diurnaltemperature variation, low relative humidity and high solar radiation reaches to about1000W/m2 on horizontal surface in summer seasons .In such environments, man losses his ability to work and to contribute effectively in thedevelopment planning due to the high thermal stress affected on him. The strategy of buildingin this regioy to understand the needs of the people but to create an indoor environment whichis suitable for healthy, and comfortable to live and work in it. Also, reduce or if possibleeliminate the energy expenditure for environmental control. In order to achieve this, attentionhas to be focused on building design which is a function of building form, orientation,location, and materials used. This study deals with the bio-climatic analysis of East El-Owauinat region and the thermal performance of building in this region to valid the EgyptianEnergy Efficiency Residential Code. The results show that, the air catcher, court and Passivecooling systems (evaporative cooling), maintained the indoor climate in the thermal huma ncomfort zone during the hottest period under the effect of climatic conditions of East El -Owauinat. Orientation, size, shape, building materials and outdoors -climatic factors influencein energy auditor of the building envelope. Also shading devices, ins ulating materials, andsmart glass achieve a harmony building with environment , and save energy by about 60%.Thermal insulation is needed for all exposed roofs and the required thermal resistance hasa minimum R-value ≥2.5 m2K/W. The required thermal resistance for walls must bebetween 0.9 and 1.3 m2K/W.

Passive design techniques: The effect of Shading devices on the thermal performance of residential buildings in Egypt

Passive design techniques: The effect of Shading devices on the thermal performance of residential buildings in Egypt