scholarly journals Comparison and analyses of two thermal performance evaluation models for a public building

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 916-926
Author(s):  
Xuemei Sun ◽  
Saihong Zhu ◽  
Hengxuan Zhu ◽  
Runze Duan ◽  
Jin Wang
Keyword(s):  
Water Temperature ◽  
Thermal Performance ◽  
Building Envelope ◽  
Thermal Mass ◽  
Heating Season ◽  
Mass Model ◽  
Indoor Temperature ◽  
Public Building ◽  
Evaluation Models ◽  
Supply Water

Abstract Recently, investigations on building thermal inertia are mainly involved with the materials of the building envelope. Usually, other influencing factors are ignored, such as room ventilation, indoor heat storage, indoor cold source, indoor heat source and human behavior. In this paper, two models based on thermodynamics are given to evaluate building thermal performance. One is thermal mass model, and the other one is thermal reserve coefficient model. Based on thermal response testing data in a non-heating season, the thermal mass model was adopted to classify the envelope type, and the delay rules between the indoor temperature and the outdoor meteorological parameters are analyzed. In a heating season, the delay rules among the outdoor temperature, indoor temperature and supply water temperature are obtained by changing the supply water temperature. Thermal performance of the targeted building is evaluated with the thermal reserve coefficient model. For the same public building, two evaluation models tend to be consistent. These two evaluation models presented in this paper can be applied for the optimal design of buildings envelope.

scholarly journals Preparation of microencapsulated PCMs for energy saving and thermal comfort of buildings

2021 ◽  
Vol 23 (09) ◽  
pp. 277-287
Author(s):  
Ashraf Mohamed Heniegal ◽  
◽  
Omar Mohamed Omar Ibrahim ◽  
Nour Bassim Frahat ◽  
Mohamed Amin ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Chemical Interaction ◽  
Spherical Shape ◽  
Building Envelope ◽  
Scanning Calorimetry ◽  
Indoor Temperature ◽  
New Techniques ◽  
Consumption Energy ◽  
Local Materials ◽  
Regular Spherical Shape

Energy improvement techniques for buildings are among the modern studies that concentrate on new techniques and methods of saving energy and improving the thermal performance in buildings. This research aims to prepare microencapsulated-PCMs (micro-PCMs) by using local materials and studied the influence of using micro-PCMs on thermal performance improvement and PCMs leakage problems improvement. The micro-PCMs of paraffin wax were prepared as the core PCMs materials while the melamine-formaldehyde polymer as the shell. The micro-PCMs were characterized through scanning electron-microscopy (SEM), energy-dispersive X-ray (EDX) spectrometry, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. Analysis results showed the prepared micro-PCMs present a regular spherical shape and confirm that the formation composite of the shell effectively encapsulated the cores. Furthermore, the absence of chemical interaction between the MF and the PW components. The micro-PCM have potential for architectural applications in the building-envelope to store thermal energy, provide indoor-temperature at the comfortable range, and reduce the consumption energy in buildings.

scholarly journals Experimental study on the dynamic thermal response of a radiant floor system in an office building

2021 ◽  
Vol 246 ◽  
pp. 10003
Author(s):  
Jing Ren ◽  
Meng Su ◽  
Xintian Zhao ◽  
Jiying Liu ◽  
Shoujie Song
Keyword(s):  
Water Temperature ◽  
Thermal Performance ◽  
Cooling System ◽  
Dynamic Change ◽  
Thermal Response ◽  
Characteristic Parameter ◽  
Intermittent Control ◽  
Cooling Mode ◽  
Floor System ◽  
Supply Water

The dynamic thermal performance of radiant terminal plays an important role in the design and control of radiant cooling system, which is shown as the dynamic thermal response of radiant floor system (RFS) under imposed control. In this paper, the field measurement method was used to study the dynamic thermal response of RFS. The RFS was activated in summer and the supply water temperature was regulated in winter to make dynamic change of thermal performance. The floor surface temperature was selected as the characteristic parameter to describe the dynamic heat transfer performance of the system, and response time τ95 and time constant τ63 were used to quantify the dynamic thermal response. The maximum τ95 was 13.5 h and τ95/τ63 was greater than or equal to 2 in the cooling mode, while τ95 and τ63 were both less than 10 h and τ95/τ63 was 1.6 in the heating mode. As a result, there was no significant lessening of temperature change rate, and the thermal response of RFS was faster under intermittent control of supply water temperature in winter. Therefore, the study aims at providing reference for making intermittent control strategy by using the dynamic thermal performance of radiant system.

scholarly journals Total Solar Reflectance Optimization of the External Paint Coat in Residential Buildings Located in Mediterranean Climates

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2729
Author(s):  
Tiago Souto ◽  
Margarida Almeida ◽  
Vítor Leal ◽  
João Machado ◽  
Adélio Mendes
Keyword(s):  
Thermal Performance ◽  
Energy Savings ◽  
Residential Buildings ◽  
Thermal Characteristics ◽  
Residential Building ◽  
Building Envelope ◽  
R Software ◽  
Indoor Temperature ◽  
Solar Reflectance ◽  
Parametric Studies

This work addresses the effect of the total solar reflectance (TSR) value of paints applied in residential buildings upon their thermal performance. A semi-detached residential building was modeled in the ESP-r software, and taken as the basis for parametric studies which assessed the effects of variations in (i) the TSR values; (ii) the thermal characteristics of the building envelope; (iii) the location/climate; and: (iv) the way how the indoor temperature is controlled. The parametric studies were used to find optimal TSR values for each combination of Location + Building envelope characteristics (mainly the existence of thermal insulation). It was concluded that paints having a carefully chosen TSR value lead to better indoor thermal temperatures if the buildings have no mechanical heating or cooling, or to energy savings of up to 32% if they do.

scholarly journals Use of Dissimilar Walling Systems on Residential Building Envelopes for Improving Their Thermal Performance

2009 ◽  
Vol 4 (2) ◽  
pp. 107-125
Author(s):  
Katherine Gregory ◽  
Behdad Moghtaderi ◽  
Adrian Page
Keyword(s):  
Energy Consumption ◽  
Thermal Performance ◽  
Residential Building ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Thermal Mass ◽  
Building Envelopes ◽  
Numerical Predictions ◽  
Brick Veneer ◽  
East And West

This paper summarises the results of a combined numerical, statistical and experimental study concerned with the use of dissimilar walling systems on the external parts of a given building envelope. The rational behind this “hybrid wall” concept, as opposed to conventional approaches where identical walls are used in a building envelope, is to achieve a more effective distribution of thermal mass across the envelope and, hence, improve the overall thermal performance of the building. The effectiveness of the “hybrid wall” concept was investigated using a series of hypothetical building modules of common Australian residential constructions, namely Light Weight (LW), Brick Veneer (BV), Reverse Brick Veneer (RBV) and Cavity Brick (CB). These designs were examined numerically using a commercial energy rating tool known as “AccuRate”, statistically using JMP software and experimentally using a novel bench-scale setup developed as part of this study. The performance of each design was evaluated by its energy consumption. The numerical predictions and experimental data highlighted that the east and west walls have the most impact on the energy consumption under Australian climatic conditions. It was found that considerable reductions in the energy consumption could be achieved in cases where the hybrid wall concept was implemented through the use of high thermal mass insulated walls on the east and west sides of the building envelope.

COMPARATIVE STUDY OF ENERGY CONSUMPTION FOR AIR CONDITIONING BETWEEN RESIDENTIAL BUILDINGS WITH TWO DIFFERENT SUBFLOORING SYSTEMS

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
H. Albayyaa ◽  
D. Hagare ◽  
S. Saha
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Residential Buildings ◽  
Energy Performance ◽  
Building Envelope ◽  
Embodied Energy ◽  
Relative Advantage ◽  
Thermal Mass ◽  
Mass Model ◽  
Modern House

Energy consumed by heating, ventilation and air conditioning account for about 40% of the total energy used in an average Australian home. The main feature that categorizes the construction systems is the thermal mass as it contributes directly to the thermal performance of the entire house. High thermal mass flooring and walls are most appropriate in climate with high diurnal (day-night) temperature ranges. High thermal mass construction system has higher embodied energy but this can offset by reducing heating and cooling energy consumption over the life span of the house. The optimum design, in terms of desirable heat gain or loss, can be achieved by considering the building orientation, thermal mass and careful design of the building envelope including roof, walls, windows and floor systems. To demonstrate relative advantage in terms of energy conservation between houses with different construction systems and thermal mass, two model houses which are detached dwelling with a floor area of 200 sqm and with two levels and four bedrooms were selected in this study. One of the model houses represented modern house with brick veneer walls and concrete slab-on-ground flooring (high thermal mass Model). The second model house represented old house with fibro walls and raised subfloor (low thermal mass Model). The analysis has been carried out using computer software (IDA ICE). The energy performance of the buildings were computed and compared. The results show that the modern house consumed 53% less energy compared to old house and hence the former is significantly cost effective over the long run.

Effect of Building Materials on Numerical Simulation of the District Heating within the Typical Building in Beijing

2012 ◽  
Vol 246-247 ◽  
pp. 360-364
Author(s):  
Fao Feng ◽  
Xun Li ◽  
De Ping Ding ◽  
Zhuang Xie
Keyword(s):  
Numerical Simulation ◽  
Root Mean Square Error ◽  
Water Temperature ◽  
Mean Square Error ◽  
Root Mean Square ◽  
Building Materials ◽  
Mean Square ◽  
Indoor Temperature ◽  
Return Water ◽  
Supply Water

In order to reduce energy consumption and analyze energy-saving potential of building materials, the principle of the energy equilibrium is applied to establish the relationship between outdoor temperature, supply and return water temperature of heating system. A numerical simulation model of supply and return water temperature is deduced. Based on the predicted air temperatures and observed indoor temperature from Haiyuan community,a simulation experiment is executed. The experiments show that the root mean square error between simulated indoor temperature and required temperature (20°C) is 0.26°C, root mean square error between predicted and observed supply water temperature is 3.76°C. When the heat transfer coefficient is decreased by 10%, the predicted supply water temperature and return water temperature is decreased 3.8% and 3.2%, respectively. This means the prediction model has a good quality.

scholarly journals Online Implementation of a Soft Actor-Critic Agent to Enhance Indoor Temperature Control and Energy Efficiency in Buildings

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 997
Author(s):  
Davide Coraci ◽  
Silvio Brandi ◽  
Marco Savino Piscitelli ◽  
Alfonso Capozzoli
Keyword(s):  
Energy Consumption ◽  
Temperature Control ◽  
Weather Conditions ◽  
Heating System ◽  
Building Envelope ◽  
Indoor Temperature ◽  
Model Free ◽  
Occupancy Patterns ◽  
Online Implementation ◽  
Indoor Temperature Control

Recently, a growing interest has been observed in HVAC control systems based on Artificial Intelligence, to improve comfort conditions while avoiding unnecessary energy consumption. In this work, a model-free algorithm belonging to the Deep Reinforcement Learning (DRL) class, Soft Actor-Critic, was implemented to control the supply water temperature to radiant terminal units of a heating system serving an office building. The controller was trained online, and a preliminary sensitivity analysis on hyperparameters was performed to assess their influence on the agent performance. The DRL agent with the best performance was compared to a rule-based controller assumed as a baseline during a three-month heating season. The DRL controller outperformed the baseline after two weeks of deployment, with an overall performance improvement related to control of indoor temperature conditions. Moreover, the adaptability of the DRL agent was tested for various control scenarios, simulating changes of external weather conditions, indoor temperature setpoint, building envelope features and occupancy patterns. The agent dynamically deployed, despite a slight increase in energy consumption, led to an improvement of indoor temperature control, reducing the cumulative sum of temperature violations on average for all scenarios by 75% and 48% compared to the baseline and statically deployed agent respectively.

scholarly journals The Effect of the Thermal Mass of the Building Envelope on Summer Overheating of Dwellings in a Temperate Climate

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4117
Author(s):  
Tadeusz Kuczyński ◽  
Anna Staszczuk ◽  
Piotr Ziembicki ◽  
Anna Paluszak
Keyword(s):  
Building Materials ◽  
Heat Waves ◽  
Residential Buildings ◽  
Building Envelope ◽  
Temperate Climate ◽  
Maximum Temperature ◽  
Thermal Mass ◽  
Occupant Behavior ◽  
Average Maximum ◽  
Night Ventilation

The main objective of this paper is to demonstrate the effectiveness of increasing the thermal capacity of a residential building by using traditional building materials to reduce the risk of its excessive overheating during intense heat waves in a temperate climate. An additional objective is to show that the use of this single passive measure significantly reduces the risk of overheating in daytime rooms, but also, though to a much lesser extent, in bedrooms. Increasing the thermal mass of the room from light to a medium heavy reduced the average maximum daily temperature by 2.2K during the first heat wave and by 2.6K during the other two heat waves. The use of very heavy construction further reduced the average maximum temperature for the heat waves analyzed by 1.4K, 1.2K and 1.7K, respectively, giving a total possible reduction in maximum daily temperatures in the range of 3.6 °C, 3.8 °C and 4.3 °C. A discussion of the influence of occupant behavior on the use of night ventilation and external blinds was carried out, finding a significant effect on the effectiveness of the use of both methods. The results of the study suggest that in temperate European countries, preserving residential construction methods with heavy envelopes and partitions could significantly reduce the risk of overheating in residential buildings over the next few decades, without the need for night ventilation or external blinds, whose effectiveness is highly dependent on individual occupant behavior.

scholarly journals Influence of Indoor Temperature Exposure on Emergency Department Visits Due to Infectious and Non-Infectious Respiratory Diseases for Older People

2021 ◽  
Vol 18 (10) ◽  
pp. 5273
Author(s):  
Chien-Cheng Jung ◽  
Nai-Tzu Chen ◽  
Ying-Fang Hsia ◽  
Nai-Yun Hsu ◽  
Huey-Jen Su
Keyword(s):  
Emergency Department ◽  
Respiratory Diseases ◽  
Significant Risk ◽  
Cumulative Effect ◽  
Emergency Department Visits ◽  
Heating Season ◽  
Indoor Temperature ◽  
Distributed Lag ◽  
Poisson Function ◽  
Temperature Exposure

Previous studies have demonstrated that outdoor temperature exposure was an important risk factor for respiratory diseases. However, no study investigates the effect of indoor temperature exposure on respiratory diseases and further assesses cumulative effect. The objective of this study is to study the cumulative effect of indoor temperature exposure on emergency department visits due to infectious (IRD) and non-infectious (NIRD) respiratory diseases among older adults. Subjects were collected from the Longitudinal Health Insurance Database in Taiwan. The cumulative degree hours (CDHs) was used to assess the cumulative effect of indoor temperature exposure. A distributed lag nonlinear model with quasi-Poisson function was used to analyze the association between CDHs and emergency department visits due to IRD and NIRD. For IRD, there was a significant risk at 27, 28, 29, 30, and 31 °C when the CDHs exceeded 69, 40, 14, 5, and 1 during the cooling season (May to October), respectively, and at 19, 20, 21, 22, and 23 °C when the CDHs exceeded 8, 1, 1, 35, and 62 during the heating season (November to April), respectively. For NIRD, there was a significant risk at 19, 20, 21, 22, and 23 °C when the CDHs exceeded 1, 1, 16, 36, and 52 during the heating season, respectively; the CDHs at 1 was only associated with the NIRD at 31 °C during the cooling season. Our data also indicated that the CDHs was lower among men than women. We conclude that the cumulative effects of indoor temperature exposure should be considered to reduce IRD risk in both cooling and heating seasons and NIRD risk in heating season and the cumulative effect on different gender.

Sign in / Sign up

Export Citation Format

Share Document