scholarly journals The calculation of the thermal mode of a room with automatic regulation of climate systems

Vestnik MGSU ◽  
2020 ◽  
pp. 585-591
Author(s):  
Oleg D. Samarin
Keyword(s):  
Heat Flow ◽  
Heat Supply ◽  
Climate System ◽  
Automatic Regulation ◽  
Thermal Mode ◽  
Indoor Climate ◽  
Indoor Temperature ◽  
Ongoing Research ◽  
Analytical Expression ◽  
Climate Systems

Introduction. The ongoing research of the indoor temperature, regulated by automatically operating climate systems, remains relevant if focused on identification of dependencies which are sufficiently accurate with regard for the majority of essential factors and represented in the engineering format. The mission of the research is to identify a dependency between indoor temperature and time in case of irregular heat supply in the context of prorated heat flow regulation by indoor climate systems. The exponential nature of this dependency serves as the research hypothesis. Materials and methods. The author has employed and analyzed the principal equations connecting the most important constituents of a heat flow in a room that has automated climate systems in the context of discontinuous changes. The author has employed a computational model of a non-steady temperature environment of a ventilated room. The proposed model is based on the solution of a system of differential equations describing heat conductivity and transfer on indoor surfaces. The author has composed and analytically solved the general differential equation describing the indoor thermal balance with regard for the climate system’s feedback. Results. The author has developed an analytical expression describing the indoor space heating rate in case of prorated temperature regulation by the climate system and irregular heat supply. The analytical expression represents an exponential function of the square root of the time span starting from the moment of a heat supply spike. The author used a residential house in Moscow to analyze the nature of indoor temperature fluctuations with and without heat regulation. Conclusions. The author has proven that an indoor temperature rate is mainly driven by the relation between the transmission coefficient of a climate system and the thermal inertia of “massive” building envelopes in case of irregular thermal exposure. The author makes the point that a simplified analytical solution is proven true by the results of the analysis performed with the help of a numerical model. It’s been identified that the ultimate value of an indoor temperature increment is determined as the relation between the heat gain value and the parameter which is proportionate to the transfer coefficient.

scholarly journals Predicting Indoor Temperature Distribution Based on Contribution Ratio of Indoor Climate (CRI) and Mobile Sensors

Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 458
Author(s):  
Yanan Zhao ◽  
Zihan Zang ◽  
Weirong Zhang ◽  
Shen Wei ◽  
Yingli Xuan
Keyword(s):  
Temperature Distribution ◽  
Relative Error ◽  
Prediction Accuracy ◽  
Prediction Method ◽  
Mobile Sensors ◽  
Average Relative Error ◽  
Contribution Ratio ◽  
Mobile Sensor ◽  
Indoor Climate ◽  
Indoor Temperature

In practical building control, quickly obtaining detailed indoor temperature distribution is necessary for providing satisfying personal comfort and improving building energy efficiency. The aim of this study is to propose a fast prediction method for indoor temperature distribution without knowing the thermal boundary conditions in practical applications. In this method, the index of contribution ratio of indoor climate (CRI), which represents the independent contribution of each heat source to the temperature distribution, has been combined with the air temperature collected by one mobile sensor at the height of the working area. Based on a typical office model, the effectiveness of using mobile sensors was discussed, and the influence of its acquisition height and acquisition distance on the prediction accuracy was analyzed as well. The results showed that the proposed prediction method was effective. When the sensors fixed on the wall were used to predict the indoor temperature distribution, the maximum average relative error was 27.7%, whereas when the mobile sensor was used to replace the fixed sensors, the maximum average relative error was 4.8%. This indicates that using mobile sensors with flexible acquisition location can help promote both reliability and accuracy of temperature prediction. In the human activity area, data from a set of mobile sensors were used to predict the temperature distribution at four heights. The prediction accuracy was 2.1%, 2.1%, 2.3%, and 2.7%, respectively. However, the influence of acquisition distance of mobile sensors on prediction accuracy cannot be ignored. The distance should be large enough to disperse the distribution of the acquisition points. Due to the influence of airflow, some distance between the acquisition points and the room boundaries should be given.

scholarly journals Development of engineering calculator for heating systems

2021 ◽  
Vol 263 ◽  
pp. 04001
Author(s):  
Andrei Melekhin
Keyword(s):  
Heat Flow ◽  
Heat Carrier ◽  
Heat Supply ◽  
Water Systems ◽  
Heat Energy ◽  
Thermal Loads ◽  
Calculation Algorithm ◽  
Systematic Analysis ◽  
Building Projects ◽  
Heating Systems

The author has developed an engineering calculator for calculating the heat flow for heating buildings according to the enlarged parameters of the object. The algorithm of the calculator is based on the method of determining the amount of heat energy and heat carrier in water systems of municipal heat supply. The author carried out a systematic analysis of thermal loads on heating of buildings in Russia according to the data of implemented building projects. With this in mind, new coefficients a, n were calculated to determine the specific heating characteristics of the building for newly constructed buildings. The algorithm for calculating the heating of buildings according to the enlarged parameters of the object is corrected. The calculation algorithm is implemented in the software

scholarly journals A multiple Linear Regression Model to predict indoor temperature trend in historic buildings for book conservation: the case study of “Sala del Dottorato” in Palazzo Murena, Italy

2021 ◽  
Vol 2069 (1) ◽  
pp. 012142
Author(s):  
Elisa Moretti ◽  
Maria Giulia Proietti ◽  
Ettore Stamponi
Keyword(s):  
Linear Regression ◽  
Regression Model ◽  
Multiple Linear Regression ◽  
Linear Regression Model ◽  
Multiple Linear Regression Model ◽  
Temperature Trend ◽  
Critical Conditions ◽  
Historic Buildings ◽  
Indoor Climate ◽  
Indoor Temperature

Abstract The indoor climate of historic buildings is governed by the desire to preserve them, their interiors and to ensure human comfort. For preservation of cultural heritage and libraries, relative humidity and temperature are very important parameters, including their amplitudes and changes rate in time. In the present study an experimental campaign of thermo-hygrometric parameters inside of “Sala del Dottorato”, located in Palazzo Murena (Perugia), is carried out. In this room a great number of rare and ancient books are preserved. The paper deals with the study and the evaluation of the correlation between outdoor and indoor microclimate conditions in the room, to ensure the proper conservation of the books; it is aimed at understanding how the two parameters follow outdoor variations and how the hygrothermal inertia of the building can mitigate these variations. This is done, specifically for temperature, which is the most critical aspect. Thanks to a continuous monitoring system for indoor and outdoor thermo-hygrometric parameters, a Multiple Linear Regression model is developed in order to predict and analyse the indoor temperature trend. This model allows to estimate a future forecast of this parameter and to predict in advance critical conditions for correct conservation.

scholarly journals Indoor climate and energy performance in nearly zero energy day care centers and school buildings

2019 ◽  
Vol 111 ◽  
pp. 02003 ◽  
Author(s):  
Kaiser Ahmed ◽  
Kalle Kuusk ◽  
Henrik Heininen ◽  
Endrik Arumägi ◽  
Targo Kalamees ◽  
...  
Keyword(s):  
Energy Use ◽  
Ventilation System ◽  
Energy Performance ◽  
Physical Parameters ◽  
Airflow Rate ◽  
Full Time ◽  
Indoor Climate ◽  
Indoor Temperature ◽  
Measured Energy ◽  
Time Operation

This study presents the assessment of actual indoor climate condition and energy performance in eight NZEB school and daycare centers of NERO H2020 project. Physical parameters such as indoor temperature, relative humidity, CO2, airflow rate and temperature were measured during heating and cooling seasons, in parallel with an occupants’ questionnaires survey. Besides, calculated and measured energy data was collected from energy performance certificates and energy bills. Thermal comfort and IAQ were assessed based on categories in EN15251 standard with color footprints. Results showed that all the buildings had good or excellent indoor climate during the heating season. However, a large percentage of occupied hours were categorized as category IV during the cooling season, which mainly occurred due to too low indoor temperature caused by the low outdoor temperature during the measurement period. Also, all buildings achieved low CO2 levels. Moreover, the conducted questionaries’ survey showed good correlation with measured results for all buildings except in one building, which had odor and noise problems. In contrast, the measured energy use in 5 buildings out of 7 was increased by factor 2.1-3.0 compared to calculated annual energy use due to a full-time operation of the ventilation system and presence of hot kitchens.

Guess-Work and Reasonings on Centennial Evolution of Surface Air Temperature in Russia. Part IV: Towards Economic Estimations of Climate-Related Damages from the Bifurcation Analysis Viewpoint

2016 ◽  
Vol 26 (12) ◽  
pp. 1630033 ◽  
Author(s):  
Yury Kolokolov ◽  
Anna Monovskaya
Keyword(s):  
Bifurcation Analysis ◽  
Time Window ◽  
Self Regulation ◽  
Climate Dynamics ◽  
Climate System ◽  
The Novel ◽  
Time Pattern ◽  
Local Climate ◽  
Climate Systems ◽  
Qualitative Changes

The paper completes the cycle of the research devoted to the development of the experimental bifurcation analysis (not computer simulations) in order to answer the following questions: whether qualitative changes occur in the dynamics of local climate systems in a centennial timescale?; how to analyze such qualitative changes with daily resolution for local and regional space-scales?; how to establish one-to-one daily correspondence between the dynamics evolution and economic consequences for productions? To answer the questions, the unconventional conceptual model to describe the local climate dynamics was proposed and verified in the previous parts. That model (HDS-model) originates from the hysteresis regulator with double synchronization and has a variable structure due to competition between the amplitude quantization and the time quantization. The main advantage of the HDS-model is connected with the possibility to describe “internally” (on the basis of the self-regulation) the specific causal effects observed in the dynamics of local climate systems instead of “external” description of three states of the hysteresis behavior of climate systems (upper, lower and transient states). As a result, the evolution of the local climate dynamics is based on the bifurcation diagrams built by processing the data of meteorological observations, where the strange effects of the essential interannual daily variability of annual temperature variation are taken into account and explained. It opens the novel possibilities to analyze the local climate dynamics taking into account the observed resultant of all internal and external influences on each local climate system. In particular, the paper presents the viewpoint on how to estimate economic damages caused by climate-related hazards through the bifurcation analysis. That viewpoint includes the following ideas: practically each local climate system is characterized by its own time pattern of the natural qualitative changes in temperature dynamics over a century, so, any unified time window to determine the local climatic norms seems to be questionable; the temperature limits determined for climate-related technological hazards should be reasoned by the conditions of artificial human activity, but not by the climatic norms; the damages caused by such hazards can be approximately estimated in relation to the average annual profit of each production. Now, it becomes possible to estimate the minimal and maximal numbers of the specified hazards per year in order, first of all, to avoid unforeseen latent damages. Also, it becomes possible to make some useful relative estimation concerning damage and profit. We believe that the results presented in the cycle illustrate great practical competence of the current advances in the experimental bifurcation analysis. In particular, the developed QHS-analysis provides the novel prospects towards both how to adapt production to climatic changes and how to compensate negative technological impacts on environment.

Impact of Hydrophobic Additives on Properties of Clay Plaster

2016 ◽  
Vol 824 ◽  
pp. 92-99
Author(s):  
Barbora Lišková ◽  
Petr Jelínek ◽  
Milan Ostrý
Keyword(s):  
Service Life ◽  
Significant Role ◽  
Indoor Climate ◽  
Indoor Temperature ◽  
Hydrophobic Materials ◽  
Increase Service Life ◽  
Cost Efficient ◽  
The Stability ◽  
Mixture Samples

Use of clay plasters in the exterior forces owners to conduct frequent maintenance of the plaster’s surface, which may be damaged by the weather. This paper describes partial results of the research, which strives to develop cost-efficient hydrophobic additives to increase service life of exterior clay plasters. We have chosen 7 hydrophobic materials and added them to the reference prefabricated plaster mixture. Samples of the enhanced plaster were tested to evaluate the additives’ impact on the overall mechanical, thermal and moisture characteristics of the plaster. Long-term testing of the best hydrophobic additives will follow to verify their properties in real buildings. Clay plasters play a significant role for the healthy indoor climate due to the influence on the stability of the indoor temperature and humidity.

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