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).

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 Tenant-based measured electricity use in 4 large office buildings in Tallinn, Estonia

2021 ◽  
Vol 246 ◽  
pp. 04001 ◽  
Author(s):  
Andrea Ferrantelli ◽  
Hans Kristjan Aljas ◽  
Vahur Maask ◽  
Martin Thalfeldt
Keyword(s):  
Input Data ◽  
Electricity Consumption ◽  
Internal Heat ◽  
Working Hours ◽  
Energy Performance ◽  
Office Buildings ◽  
Building Performance Simulation ◽  
Electricity Use ◽  
Internal Gain ◽  
Simulation Input

The energy performance assessment of buildings during design is usually based on energy simulations with pre-defined input data from standards and legislations. Typically, the internal gain values and profiles are based on EN 16798–1. However, studies have shown that the real electricity use of plug load and lighting varies more smoothly than in the profiles of EN 16798–1 where zero occupancy outside working hours is assumed. This might result in sub-optimal building solutions due to inadequate building performance simulation input data. The aim of this work is to structure and analyse data from a total of 196 electricity meters in 4 large office buildings in Tallinn, Estonia. Typically, 3 to 8 electricity meters were installed per floor with the consumption coming mainly from plug loads and electric lighting. The data had been gathered between the years 2016–2020 with either 1 or 24 hour time steps, depending on the building and the electricity meter. 3 out of the 4 buildings had an average normalized energy usage slightly below the modelling value calculated according to EN16798–1. Some office spaces stood out with an abnormally high electricity consumption, however, the 24-hour distributions were fairly compact, meaning quite steady consumption patterns. When looking at the dispersion of energy consumption per 24h, averaged over all given offices in a building, no outliers stood out, either. This means that there are not many days when the average consumption and internal heat gains of all offices were simultaneously well below the mean. Additionally, major events like holidays and the COVID19-induced lockdown show up well on the graphs, but also planned changes in occupancy can be seen.

scholarly journals PCSP’s Diagonal Tie Connectors Thermal Bridges Impact on Energy Performance and Operational Cost: Case Study of a High-Rise Residential Building in Estonia

2020 ◽  
Vol 172 ◽  
pp. 08006
Author(s):  
Martin Kiil ◽  
Martin-Sven Käärid ◽  
Paul Klõšeiko ◽  
Karl-Villem Võsa ◽  
Raimo Simson ◽  
...  
Keyword(s):  
Energy Demand ◽  
Residential Building ◽  
Energy Performance ◽  
Relative Increase ◽  
Dynamic Simulations ◽  
Climatic Regions ◽  
High Rise ◽  
Thermal Bridge ◽  
Heating Energy Demand ◽  
Air Circulation

This study analyses the effect of air circulation around diagonal tie connectors in precast sandwich panels on heating energy demand, energy performance value and heating costs of a sample residential building. Dynamic simulations were performed using 4 different climatic boundary conditions: Estonian test reference year, Estonian 48-year weather dataset as well as data from Eastern Germany and Northern Finland. The results show that the effect of the thermal bridge is most noticeable in total room heating energy demand (increase of 10.3%), while the influence on energy performance value was 1.1%. The relative increase of total room heating energy demand was similar (7.0-10.3%) in all studied climatic regions.

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.

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 Energy, Economic, and Environmental Performance of a Single-Family House in Chile Built to Passivhaus Standard

2021 ◽  
Vol 13 (3) ◽  
pp. 1199
Author(s):  
Camilo Bravo-Orlandini ◽  
José M. Gómez-Soberón ◽  
Claudia Valderrama-Ulloa ◽  
Francisco Sanhueza-Durán
Keyword(s):  
Energy Consumption ◽  
Environmental Performance ◽  
Energy Demand ◽  
Energy Use ◽  
Initial Step ◽  
Energy Performance ◽  
Primary Energy ◽  
Single Family ◽  
Passive Strategies ◽  
Heating Energy Demand

The energy consumption of buildings accounts for 22% of total global energy use and 13% of global greenhouse gas emissions. In this context, this study aims to evaluate the energy, economic, and environmental performance of housing in Chile built according to the Passivhaus (PH) standard. The standard was applied to housing in eight representative climate zones with a single-family residence as reference. The analysis incorporated passive strategies, which are considered as pillars of the PH. The energy performance was analyzed using the Passive House Planning Package software (PHPP), version 9.6a. The results showed that when every passive strategy is implemented, the heating energy demand decreases by 93%, while the refrigeration demand is nonexistent. These results were achieved through a 37% increase in the overall initial budget investment, which will be amortized over an 11-year period. In this way, the primary energy consumption is reduced by 32% and, correspondingly, CO2 emissions are reduced by 39%. In modern Chile, it is difficult (but not impossible) to incorporate PH. However, governmental programs and aids could represent an initial step. Therefore, this research will help to identify strategies for incorporating PH in Chile, with the aim of improving the energy performance of housing.

scholarly journals Identification of Environmental and Contextual Driving Factors of Air Conditioning Usage Behaviour in the Sydney Residential Buildings

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 122
Author(s):  
Bongchan Jeong ◽  
Jungsoo Kim ◽  
Zhenjun Ma ◽  
Paul Cooper ◽  
Richard de Dear
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Energy Use ◽  
Residential Buildings ◽  
Significant Proportion ◽  
Building Energy ◽  
Energy Performance ◽  
Time Of Day ◽  
Performance Simulation ◽  
Building Energy Performance

Air conditioning (A/C) is generally responsible for a significant proportion of total building energy consumption. However, occupants’ air conditioning usage patterns are often unrealistically characterised in building energy performance simulation tools, which leads to a gap between simulated and actual energy use. The objective of this study was to develop a stochastic model for predicting occupant behaviour relating to A/C cooling and heating in residential buildings located in the Subtropical Sydney region of Australia. Multivariate logistic regression was used to estimate the probability of using A/C in living rooms and bedrooms, based on a range of physical environmental (outdoor and indoor) and contextual (season, day of week, and time of day) factors observed in 42 Sydney region houses across a two-year monitoring period. The resulting models can be implemented in building energy performance simulation (BEPS) tools to more accurately predict indoor environmental conditions and energy consumption attributable to A/C operation.

scholarly journals Sensitivity analysis of heating a typical UK dwelling and implications for retrofit design

2021 ◽  
Vol 2042 (1) ◽  
pp. 012148
Author(s):  
Kate Simpson ◽  
Peter Childs ◽  
Jennifer Whyte
Keyword(s):  
Sensitivity Analysis ◽  
Energy Demand ◽  
Energy Performance ◽  
Space Heating ◽  
Set Point ◽  
Model Based ◽  
Domestic Energy ◽  
Heating Energy Demand ◽  
The Impact ◽  
Retrofit Design

Abstract The aim of this research is to quantify the impact of heating set point on space heating energy demand for a typical UK dwelling. Retrofit includes fabric energy efficiency improvements. Energy performance certificates (EPCs) inform the householder of typical savings per measure, but this has previously been found to inaccurately estimate space heating energy demand, leading to errors in 'typical savings' presented to householders. The most sensitive inputs have been found to be temperature set point, followed by fabric efficiency. The BREDEM methodology assumes a temperature of 21°C for nine hours a day, rather than ~16°C and ~20°C found in research. The methods used to inform this study are local sensitivity analysis of the domestic energy model, based on a typical dwelling example with calibrated inputs. This is done using an open calibrated Python model, based on BREDEM. The impact of heating patterns on space heating energy demand are modelled pre retrofit; according to differing heating set points, following wall and loft fabric upgrade and full fabric upgrade. The BREDEM heating set point assumptions lead to space heating energy demand predicted ~50-100 kWh/m2/yr higher than real heating set points. Implications for retrofit design and EPCs are discussed.

Performance Simulation of External Metal Mesh Screen Devices: A Case Study

2016 ◽  
Vol 861 ◽  
pp. 151-159
Author(s):  
Georgios Gourlis ◽  
Farhang Tahmasebi ◽  
Ardeshir Mahdavi
Keyword(s):  
Energy Demand ◽  
Residential Buildings ◽  
Energy Performance ◽  
Metal Mesh ◽  
Performance Simulation ◽  
European Climate ◽  
Mesh Screen ◽  
Detailed Simulation ◽  
Shading Device ◽  
The Impact

Early design decisions with regard to building facade characteristics play a significant role in the resulting building's thermal performance. In this context, external metal mesh screens -used as a permanent second facade skin- are a rather new shading alternative, particularly in non-residential buildings. It has been suggested that such products can filter excessive incident solar radiation while maintaining the facade’s transparent quality. Given the multifaceted implications of this shading device for building energy performance, we undertook a detailed simulation-based study to evaluate the impact of metal mesh screens on annual energy demand for heating, cooling and electric lighting in different European climate zones. Possible design variations were considered in terms of mesh screen translucency, window to wall ratio and facade orientation. The feasibility of using such a shading strategy to provide passive cooling during summer was also explored, along with suitable ventilation scenarios. Toward this end, we examined a number of existing approaches to simulate metal mesh screens and identified their capabilities and limitations. A typical office space was tested in three European locations, taking local building construction standards into account. The results of this study can help planners in their choice of the appropriate shading strategy and provide recommendations for the application of metal mesh screens according to the climatic and architectural criteria.

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.

Sign in / Sign up

Export Citation Format

Share Document