scholarly journals BIURO PATALPOS ŠILUMOS PRITEKIŲ TYRIMAS / INVESTIGATION OF HEAT GAINS IN AN OFFICE

2018 ◽  
Vol 10 (0) ◽  
pp. 1-6
Author(s):  
Laura Juršėnaitė ◽  
Violeta Motuzienė
Keyword(s):  
Heat Balance ◽  
Energy Demand ◽  
Information Technologies ◽  
Cooling System ◽  
Internal Heat ◽  
Energy Performance ◽  
Experimental Simulation ◽  
Maximum Heat ◽  
Room Model ◽  
The Heat Balance

Increasing the energy efficiency of buildings, heat losses through envelope and infiltration become very low, therefore, the proportion of the heat gains in the heat balance of the building increases. Due to their abundance of computer equipment, intensive lighting and the abundance of employees the information technologies’ (IT) staff offices are characterized by high internal heat gains. Formally, such offices are not distinguished when designing the building and its energy performance, values of internal heat gains are the same as for usual offices. Insufficient attention to the detailed differentiation of the heat gains may lead to the inadequate assessment of the energy performance of the building, insufficient design power of the cooling system. The aim of this work is to determine the influence of internal heat gains on the heat balance of a existing IT office. The heat gains are initially determined experimentally and compared with the values calculated in accordance with STR 2.01.02:2016, the room model is calibrated in the IDA ICE software, which is used to analyze building’s annual energy demand sensitivity to internal heat gains. It was defined that in the case of maximum heat gains, the experimental internal heat gain are 63–81% higher than the ones, calculated in accordance with norms. The annual heating demand is 31% lower, and the cooling demand is 56% higher according to the experimental simulation compared to standardized simulation results. Santrauka Didinant pastatų energinį naudingumą, šilumos nuostoliai per atitvaras ir dėl infiltracijos tampa nykstamai maži, todėl pastato šilumos balanse didėja vidiniams šilumos pritekiams tenkanti dalis. Dideliais vidiniais šilumos pritekiais pasižymi informacinių technologijų (IT) personalo biurai dėl juose gausiai naudojamos kompiuterinės įrangos, intensyvaus apšvietimo bei darbuotojų gausos. Formaliai tokie biurai, projektuojant pastatą ir jo energinį naudingumą, nėra išskiriami, jiems taikomos tokios pačios vidinių pritekių vertės kaip ir įprastiems biurams. Nepakankamas dėmesys išsamesniam šilumos pritekių diferencijavimui gali lemti tai, kad pastato naudingumas bus įvertintas netinkamai, vėsinimo sistemos bus suprojektuotos nepakankamos galios (projektinei šildymo galiai šilumos pritekiai įtakos neturi). Šio darbo tikslas yra nustatyti vidinių šilumos pritekių įtaką realaus IT biuro patalpos šilumos balansui. Šilumos pritekiai pradžioje nustatomi eksperimentiniu būdu ir lyginami su dydžiais, apskaičiuotais pagal STR 2.01.02:2016 standartą, patalpos modelis kalibruojamas IDA ICE programoje, kurioje atliekama pastato metinių energijos poreikių priklausomybės nuo vidinių šilumos pritekių parametrinė analizė. Nustatyta, kad maksimalūs paros eksperimentiniai vidiniai pritekiai yra 63–81 % didesni nei apskaičiuoti pagal reglamentą, metiniai šildymo poreikiai pagal eksperimentinius duomenis yra 31 % mažesni, o vėsinimo poreikiai 56 % didesni lyginant su gautais taikant normines pritekių vertes.

scholarly journals ASSESSMENT OF ENERGY PERFORMANCE GAP OF AN OFFICE BUILDING

2021 ◽  
Vol 13 (0) ◽  
pp. 1-6
Author(s):  
Rasa Džiugaitė-Tumėnienė ◽  
Domas Madeikis
Keyword(s):  
Energy Efficiency ◽  
Energy Demand ◽  
Internal Heat ◽  
Energy Performance ◽  
Energy Model ◽  
Indoor Climate ◽  
Performance Gap ◽  
Protection Measures ◽  
Climate Parameters

The high share of global energy costs to create an indoor climate has been of increasing interest to the global community for several decades and is increasingly the focus of policy. This paper analyses the energy performance gap between actual energy consumption and energy demand obtained during the dynamic energy simulation and building certification. To identify the energy performance gap, an existing office of energy efficiency class B was selected as a case study. The simulation program IDA Indoor Climate and Energy was used to create a dynamic energy model, based on the designed documentation and the actual indoor climate parameters recorded by the building management system. The results of the case study showed that the accuracy and reliability of the results presented by the dynamic energy model of the building directly depend on the assumptions. The correct values of the internal heat gains, indoor climate parameters, human behavior, air quality levels at different times of the day and season, HVAC system operation parameters and operation modes, specific fan powers of ventilation systems, the seasonal energy efficiency of cooling equipment and characteristics of sun protection measures have to be selected.

scholarly journals Energy Monitoring in a Heating and Cooling System in a Building Based on the Example of the Turówka Hotel

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1968 ◽  
Author(s):  
Marek Borowski ◽  
Piotr Mazur ◽  
Sławosz Kleszcz ◽  
Klaudia Zwolińska
Keyword(s):  
Energy Consumption ◽  
Energy Management ◽  
Energy Demand ◽  
Cooling System ◽  
Energy Performance ◽  
High Energy ◽  
Building Envelope ◽  
Large Variability ◽  
Heating And Cooling ◽  
And Control

The energy consumption of buildings is very important for both economic and environmental reasons. Newly built buildings are characterized by higher insulation and airtightness of the building envelope, and are additionally equipped with technologies that minimize energy consumption in order to meet legal requirements. In existing buildings, the modernization process should be properly planned, taking into account available technologies and implementation possibilities. Hotel buildings are characterized by a large variability of energy demand, both on a daily and a yearly basis. Monitoring systems, therefore, provide the necessary information needed for proper energy management in the building. This article presents an energy analysis of the Turówka hotel located in Wieliczka (southern Poland). The historical hotel facility is being modernized as part of the project to adapt the building to the requirements of a sustainable building. The modernization proposal includes a trigeneration system with a multifunctional reverse regenerator and control module using neural algorithms. The main purpose is to improve the energy efficiency of the building and adapt it to the requirements of low-energy buildings. The implementation of a monitoring system enables energy consumption to be reduced and improves the energy performance of the building, especially through using energy management systems and control modules. The proposed retrofit solution considers the high energy consumption, structure of the energy demand, and limits of retrofit intervention on façades.

scholarly journals Sensitivity analysis of peak and annual space cooling load at simplified office dynamic building model

2019 ◽  
Vol 111 ◽  
pp. 04038
Author(s):  
Vasco Zeferina ◽  
Christina Birch ◽  
Rodger Edwards ◽  
Ruth Wood
Keyword(s):  
Energy Demand ◽  
Screening Method ◽  
Peak Load ◽  
Internal Heat ◽  
Climate Change Impacts ◽  
Building Design ◽  
Energy Performance ◽  
Design Parameters ◽  
Space Cooling ◽  
Ventilation Rates

The focused investigation of building design is necessary to understand and quantify the implication of different design parameters on their energy performance. The design of future buildings is a major challenge, as current designs may be inappropriate in a future with global warming due to climate change impacts. In addition this understanding is necessary to be able to predict timing and profile of future energy demand, which is crucial for the long-term planning of energy infrastructures – particularly electricity. In this paper, the Morris Elementary Effects method is used as a screening method, to identify the key parameters of the design and operation of office buildings that affect the estimation of space cooling peak load and annual energy demand. Internal heat gains, cooling set-point and ventilation rates are identified as the parameters with larger implications for both annual and peak space cooling demand. In future climate scenarios, the magnitude of change of annual space cooling demand is significantly (around five times) larger than the change in the peak demand. Asides from the potential increase of space cooling demand in future scenarios, the sensitivity of the space cooling demand relative to the change in design parameters is potentially much larger.

scholarly journals The heat loss calculating methods of external walls in the buildings reconstruction

2018 ◽  
Vol 230 ◽  
pp. 02038 ◽  
Author(s):  
Varvara Vinnichenko ◽  
Azat Gabitov ◽  
Aleksandr Salov ◽  
Askar Gaisin ◽  
Dmitriy Kuznetsov
Keyword(s):  
Finite Element ◽  
Heat Conduction ◽  
Heat Loss ◽  
Balance Equation ◽  
Heat Balance ◽  
Operating Experience ◽  
Energy Performance ◽  
Heat Balance Equation ◽  
The Heat Balance ◽  
Window Frames

Heat loss analysis in cladding of brick buildings under reconstruction is presented. Thermograms obtained under thermovision inspection and window systems operating experience in conditions of the Republic of Bashkortostan are thoroughly studied. Live issue of increasing buildings energy performance in public utilities sector may largely be solved by replacement of existing window units made of wood to new PVC profile windows equipped with multi-glazed glass units both in brick and frame-panel old buildings. Significant heat loss occurs in junctions between the window frames and the wall in jamb areas. Therefore for the heat conduction matrix for the finite element is used the heat balance equation. Use of the software application to choose certain measures to eliminate the thermal bridges enables to get the thermotechnical calculations in the junction between the window and the exterior wall in the form of temperature fields. Practical recommendations for arrangement of heat insulation in junctions between the window frames and the wall to eliminate actual defects and for normal room conditions are made under examinations. To get the heat conduction matrix for the finite element we will use the heat balance equation.

Dynamic Analysis on Energy-Saving Effect of Distributed Cooling System in TBS

2014 ◽  
Vol 472 ◽  
pp. 1047-1051
Author(s):  
Tian Jian Yang ◽  
Yang Li
Keyword(s):  
Dynamic Analysis ◽  
Energy Saving ◽  
Dynamic Simulation ◽  
Heat Balance ◽  
Air Conditioning ◽  
Cooling System ◽  
Balance Model ◽  
Saving Effect ◽  
The Heat Balance

In order to evaluate the energy-saving effect of Distributed Cooling System (DCS) analytically, the heat balance model of DCS in a TBS is established and then dynamic simulation is employed. The numeral results show that DCS has much better energy-saving effect than traditional air conditioning (AC) and the energy-saving effect is steady all year round.

The impact of thermal mass on cold and hot climate zones of Portugal

2016 ◽  
Vol 26 (6) ◽  
pp. 733-743 ◽  
Author(s):  
Jorge S. Carlos
Keyword(s):  
Heat Capacity ◽  
Thermal Resistance ◽  
Energy Demand ◽  
Dynamic Modelling ◽  
Internal Heat ◽  
Energy Performance ◽  
Thermal Mass ◽  
Steady State Condition ◽  
Climate Conditions ◽  
The Impact

The aim of this paper is focused on the energy performance of buildings containing massive wall alternatives. The analysis comprised the comparison of the heating and cooling loads of seven characteristic wall configurations of one sample building with different dynamic internal heat capacity (ISO 13790:2008) in spite of the equal thermal resistance. The equal thermal resistance, as derived from simple steady-state condition, was imposed in order to allow research of effects solely attributed to the wall heat capacity on the building performance. A detached one floor dwelling exposed to different climate conditions in Portugal was analysed to illustrate the effect of the same wall in terms of energy demand during cold and hot weather conditions. A whole building dynamic modelling using EnergyPlus was employed for the energy analysis. The best thermal performance was obtained with massive walls that were located at the inner side, for a very heavy weight building and high building time constant.

scholarly journals Aspects of adapting the cooling installation in a food cold storage system to the applicable f-gas regulations

2021 ◽  
pp. 30-42
Author(s):  
Filip BRAŃSKI ◽  
Adam RUCIŃSKI
Keyword(s):  
Cold Storage ◽  
Heat Balance ◽  
Main Part ◽  
Cooling System ◽  
Storage System ◽  
Operating Parameters ◽  
Alternative Refrigerant ◽  
System Reconstruction ◽  
Cold Store ◽  
The Heat Balance

The paper presents the methodology of the analysis of the cooling system reconstruction in a food cold store under the regulations applicable from the beginning of 2020. They result from the so-called the F-Gas Act concerns the use of refrigerants with a low environmental impact. First, the elements of the existing regulations on the use of refrigerants were discussed. This part of article focus mainly on the F-Gas Act and the regulations it entails. Then, the refrigerants used so far in refrigeration systems were compared with substitutes, which were the only ones that have been approved for use since 2020, thanks to the low GWP index. Their properties are briefly described, along with the benefits (primarily for the environment) of their use. The main part of the work is the analysis of the reconstruction of the cooling system to use an alternative refrigerant. During the work, the construction of the cold storage was analyzed together with the system currently working in analysed location. Then, the heat balance was calculated, thanks to which it was possible to determine the demand for cold. Than, several refrigerants that meet the latest standards and application regulations were selected. Their operating parameters were examined, the possible variants of use were compared in relation to the determined demand for cooling and the most important operational features were summarized.

Impact of Internal Heat Gains on Building’s Energy Performance

2017 ◽  
Author(s):  
Vilūnė Lapinskienė ◽  
Violeta Motuzienė ◽  
Rasa Džiugaitė-Tumėnienė ◽  
Rūta Mikučionienė
Keyword(s):  
Energy Demand ◽  
Significant Proportion ◽  
Internal Heat ◽  
Working Hours ◽  
Energy Performance ◽  
Heating Season ◽  
Small Energy ◽  
Performance Simulation ◽  
Plug Loads ◽  
Heating Energy Demand

Internal heat gains from occupants, equipment and lighting contribute a significant proportion of the heat gains in an office space. Usage of ICT in offices is growing; on the other hand, their efficiency is also improving all the time. Increasing energy efficiency in buildings have led to the situation, when new, well insulated office buildings, with high internal gains within the working hours may cover low heating energy demand. Such buildings, even in heating dominated countries, such as Lithuania, often also suffer from overheating during the winter heating season. The paper presents the analysis of energy demand of the office building for various plug loads (ICT equipment) internal gains scenarios and demonstrates its influence on buildings energy performance. Simulation results enable to conclude, that when assessing sustainability and energy bills of the building, plug loads play a very important role. Meanwhile, assessing just energy performance influence is very small. Energy performance certification results show, that plug loads may influence energy performance label just for buildings corresponding A+ and A++ labels).

Performance and Affection Analysis on Cooling Module in the Vehicle Working Conditions

2014 ◽  
Vol 472 ◽  
pp. 348-352
Author(s):  
He Chang ◽  
Xiu Min Yu ◽  
Jing Hua Lv ◽  
Ming Zhou ◽  
Ge Li
Keyword(s):  
Simulation Model ◽  
Thermal Management ◽  
Working Conditions ◽  
Heat Balance ◽  
Air Conditioning ◽  
Cooling System ◽  
Balance Test ◽  
Simulation Results ◽  
Cooling Module ◽  
The Heat Balance

Cooling module simulation for vehicle has been built according to the heat balance test, and the simulation results are compared with the test data to verify the authenticity of the module. This simulation model provides an effective platform for vehicle thermal management analysis. Module is used to simulate the air conditioning running and to find how different ambient temperaturesto effect the performance of the cooling module. The air conditioning working and ambience temperaturewhichis significantly influence the performance of the cooling system.

scholarly journals HEAT BALANCE RESEARCH OF 3MW MARINE WIND TURBINE'S ENGINE ROOM

2012 ◽  
Vol 19 ◽  
pp. 362-373
Author(s):  
NA KANG ◽  
YANLONG JIANG ◽  
NIANYONG ZHOU ◽  
HONG SHI ◽  
ZHILI LIU ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Wind Turbine ◽  
Heat Balance ◽  
Heat Load ◽  
Cooling System ◽  
Turbine Cooling ◽  
Engine Room ◽  
Wind Turbine System ◽  
Volume Method ◽  
The Heat Balance

The increment of heat load in Wind Turbine's engine room could cause the system shut down. In this paper the heat balance of Wind Turbine's engine room is investigated according to the structure of the engine room, environmental operating requirements as well as heat-dissipating of different components of a 3MW Wind Turbine System. The heat load of the engine room is analyzed and the physical model is developed based on finite volume method. After that, the temperature distribution of the cabin is obtained under different conditions with/without the jet unit. The temperature distribution in engine compartments with different number and the arrangement of jet units is compared in this paper. Based on the analysis, the cabin cooling design is carried out to achieve the purpose of stopping heat gathering and keeping heat balance of the cabin. This work puts forward the heat balance maintenance and completes the corresponding research, which could be helpful for the optimization of large-capacity Wind Turbine cooling system.

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