scholarly journals Analysis of selected input data impact on energy demand in office building - case study

2018 ◽  
Vol 222 ◽  
pp. 01015 ◽  
Author(s):  
Joanna Sinacka ◽  
Katarzyna Ratajczak

In the building designing process special attention should be paid to energy calculations - with analysis of different input data low energy or passive house can be obtained and decision of which parameters can or cannot be changed may be made. The following input data was analysed: shape factor A/V, glazed area, internal heat gains, air tightness, efficiency of heat recovery. The results show that the input data for the energy calculations are crucial for the obtained result.

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 156
Author(s):  
Paige Wenbin Tien ◽  
Shuangyu Wei ◽  
John Calautit

Because of extensive variations in occupancy patterns around office space environments and their use of electrical equipment, accurate occupants’ behaviour detection is valuable for reducing the building energy demand and carbon emissions. Using the collected occupancy information, building energy management system can automatically adjust the operation of heating, ventilation and air-conditioning (HVAC) systems to meet the actual demands in different conditioned spaces in real-time. Existing and commonly used ‘fixed’ schedules for HVAC systems are not sufficient and cannot adjust based on the dynamic changes in building environments. This study proposes a vision-based occupancy and equipment usage detection method based on deep learning for demand-driven control systems. A model based on region-based convolutional neural network (R-CNN) was developed, trained and deployed to a camera for real-time detection of occupancy activities and equipment usage. Experiments tests within a case study office room suggested an overall accuracy of 97.32% and 80.80%. In order to predict the energy savings that can be attained using the proposed approach, the case study building was simulated. The simulation results revealed that the heat gains could be over or under predicted when using static or fixed profiles. Based on the set conditions, the equipment and occupancy gains were 65.75% and 32.74% lower when using the deep learning approach. Overall, the study showed the capabilities of the proposed approach in detecting and recognising multiple occupants’ activities and equipment usage and providing an alternative to estimate the internal heat emissions.


Author(s):  
Stephen Burke ◽  
Johnny Kronvall ◽  
Magnus Wiktorsson ◽  
Per Sahlin ◽  
Anders Ljungberg

2021 ◽  
Vol 13 (0) ◽  
pp. 1-6
Author(s):  
Rasa Džiugaitė-Tumėnienė ◽  
Domas Madeikis

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.


2020 ◽  
Vol 28 (1) ◽  
pp. 20-24
Author(s):  
Martin Jamnický ◽  
Roman Rabenseifer

AbstractThis article proposes to contribute to the discussion on environmental product declarations for buildings. Using a simple life-cycle analysis of a low-energy detached house and CO2-equivalent emissions as a comparative unit, the case study presented illustrates the problems with the initial input data related to embodied energy and a definition of the criteria for an assessment of the environmental quality of buildings. The actual case study compares the expected energy demand of a detached house in the course of its service life and the energy input (embodied energy) necessary for its assembly and for the manufacture of the individual building products. The operation of the building during its service life is described using a computer-aided building performance simulation. The input data related to the embodied energy are based on information from classical works on life cycle analyses. In addition, the article discusses the limits of building envelope improvements in terms of the thickness of thermal insulation and also stresses the increasing significance of embodied energy in the environmental assessment of buildings.


2021 ◽  
Vol 13 (17) ◽  
pp. 9491
Author(s):  
Manuel Carpio ◽  
David Carrasco

The increase in energy consumption that occurs in the residential sector implies a higher consumption of natural resources and, therefore, an increase in pollution and a degradation of the ecosystem. An optimal use of materials in the thermal envelope, together with efficient measures in the passive architectural design process, translate into lower energy demands in residential buildings. The objective of this study is to analyse and compare, through simulating different models, the impact of the shape factor on energy demand and CO2 emissions depending on the type of construction solution used in the envelope in a cold oceanic climate in South Chile. Five models with different geometries were considered based on their relationship between exposed surface and volume. Additionally, three construction solutions were chosen so that their thermal transmittance gradually complied with the values required by thermal regulations according to the climatic zone considered. Other parameters were equally established for all simulations so that their comparison was objective. Ninety case studies were obtained. Research has shown that an appropriate design, considering a shape factor suitable below 0.767 for the type of cold oceanic climate, implies a decrease in energy demand, which increased when considering architectural designs in the envelope with high values of thermal resistance.


2019 ◽  
Vol 11 (17) ◽  
pp. 4574
Author(s):  
Katsaprakakis ◽  
Kagiamis ◽  
Zidianakis ◽  
Ambrosini

This article presents the computational simulation process and the operation algorithms of the VAV and VRV systems, for indoor space conditioning, with extensive physical cooling and heat recovery. Through the introduction of appropriate operation algorithms, the article aims to highlight the high energy saving potential on indoor space conditioning, by exploiting physical cooling and heat recovery processes. The proposed algorithms are evaluated with a case study for a hydro power plant building located in the area of Lugano, Switzerland, with significant cooling needs for the whole year, due to high internal heat gains from indoor electrical equipment. This fact enables physical cooling during winter, for the cooling load coverage, and heat recovery, for the concurrent heating load coverage in different thermal zones of the building. Analytical operation algorithms are developed for a VAV and a VRV system. Both algorithms are computationally simulated. With the VAV system, 86.1% and 63.7% of the annual cooling and heating demand, respectively are covered by physical cooling and heat recovery. With the VRV system, 58.5% of the annual heating demand is covered by heat recovery. The set-up cost of the VAV system is almost twice higher than the set-up cost of the VRV system.


2018 ◽  
Vol 7 (3.7) ◽  
pp. 39
Author(s):  
Farzaneh Moayedi ◽  
Noor Amila Wan Abdullah Zawawi ◽  
Mohd Shahir Liew

Global warming mitigation is used as a requisite key to promote approaches and sustainable policies in developing countries that aim to minimize the level of carbon emission in built environment. In the past few years, energy demand has grown enormously in Malaysia. CO2 emission from energy consumption, mainly from electricity is a stark condemnation of commercial sector. Building operational energy particularly the thermal aspect, is the dominant factor that used to be highlighted and investigated due to the fact that it is the main proportion of operational energy consumption in buildings. The rate of energy dissipation in building components depends on design and environmental conditions. Accordingly, actions need to be taken in order to promote the quality of buildings in terms of heat exchanges, which can lead to a significant energy saving. Using of appropriate thermal insulation is effective way to diminish greenhouse gas emissions by reducing energy consumption. Therefore, the aim of the study is to investigate and determine the total amount of energy consumption from an office building. For reliability purposes, energy consumption from operation of baseline building was compared with the eco-friendly existing office building. Results show that, after implementation of sustainable solutions in the case study, operational energy consumption was successfully reduced to a grate extend. 


2021 ◽  
Author(s):  
Cassandra Kani-Sanchez

There is a need to better understand the performance characteristics of HR VRF systems in a cold climate. This study involved the development of a HR VRF system model in EnergyPlus, using field data from a two-storey case study office building. Using the model, this study investigated calibration with site information, climate variations, VRF indoor terminal unit reconfiguration for heat recovery improvements, right-sizing HR VRF outdoor units to raise part-load ratios, and comparing the HR VRF system to other HVAC systems for system efficiency. Challenges with achieving model calibration led to recommendations for monitoring system design and EnergyPlus modelling improvements.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shuangjun Li ◽  
Shuai Deng ◽  
Li Zhao ◽  
Weicong Xu ◽  
Xiangzhou Yuan ◽  
...  

Abstract The special report of the Intergovernmental Panel on Climate Change’s (IPCC) on global warming of 1.5 °C marks a critical point in climate negotiations, which emphasizes the importance to control the CO2 level in the atmosphere. The current technology cluster of CO2 capture is still energy-intensive which results in a substantial increase in costs, thus the efficient conversion among various forms of energy is the major topic of research. Considering that most of the existing research are primarily based on the viewpoint of energy conservation on a specific case study, the results thus could not be efficiently generalized as a condensed mechanism of energy dissipation. In this work, the entropy generation evaluation of a 4-step temperature swing adsorption (TSA) process was presented as a sample. The values and contribution distributions of various entropy generation in the thermodynamic cycle were calculated to evaluate the major energy dissipation. The results on contribution distribution of entropy generation and heat required were compared, the entropy generation distribution contributed by heat transfer decreases from 63.27% to 53.72% with internal heat recovery (IHR) method integrated. Thus the entropy generation saving potential of IHR method could be proved.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6170
Author(s):  
Jakob Carlander ◽  
Bahram Moshfegh ◽  
Jan Akander ◽  
Fredrik Karlsson

12.9% of the energy use in the EU originates from the commercial and public sector. It has therefore become a priority to optimize energy efficiency in these buildings. The purpose of this study has been to explore how energy demand in a new office building is affected by different internal heat gains, location, orientation, and façade design, and also to see how different indicators can change perspective on energy efficiency. The study was performed with simulations in IDA-ICE with different façade design and changes in internal heat gains (IHG), orientation, and location. Energy demand was then compared to two different indicators. Using a façade designed to lower solar heat gains had little effect on energy demand in the north of Sweden, but slightly more effect further south. The amount of internal heat gains had significant effect on energy demand. Making deeper studies on design and internal heat gains should therefore be prioritized in the beginning of new building projects so the most energy-efficient design can be chosen. When the indicator kWh/m2 was used, the cases with low internal heat gains were perceived as the most energy efficient, while when kWh/(m2 × hpers) (hpers = hours of use) was used, the cases with high occupancy and low electricity use were considered to be the most energy efficient. Therefore, revising the standardized indicator is of great importance.


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