scholarly journals Energy use of buildings in relation to occupancy rates

2021 ◽  
Vol 2069 (1) ◽  
pp. 012217
Author(s):  
H Davidsson ◽  
S K Chowdary ◽  
N Gentile ◽  
B Berggren ◽  
J Kanters

Abstract This paper presents basic data of the energy demand for district heating and plug loads logged by a building management system of an energy-efficient academic building located in Lund, Sweden. The data refers to the years 2019 and 2020 when occupancy varied significantly due to the Corona pandemic. The data shows that the building energy demand adapts poorly to fluctuating occupancy rates. With a possible increase of smart working in the future, building codes should account for more fluctuating occupancy rates in the modelling of the energy demand of buildings.

2020 ◽  
Vol 160 ◽  
pp. 01004 ◽  
Author(s):  
Stanislav Chicherin ◽  
Lyazzat Junussova ◽  
Timur Junussov

Proper adjustment of domestic hot water (DHW) load structure can balance energy demand with the supply. Inefficiency in primary energy use prompted Omsk DH company to be a strong proponent of a flow controller at each substation. Here the return temperature is fixed to the lowest possible value and the supply temperature is solved. Thirty-five design scenarios are defined for each load deviation index with equally distributed outdoor temperature ranging from +8 for the start of a heating season towards extreme load at temperature of -26°C. All the calculation results are listed. If a flow controller is installed, the customers might find it suitable to switch to this type of DHW supply. Considering an option with direct hot water extraction as usual and a flow controller installed, the result indicates that the annual heat consumption will be lower once network temperatures during the fall or spring months are higher. The heat load profiles obtained here may be used as input for a simulation of a DH substation, including a heat pump and a tank for thermal energy storage. This design approach offers a quantitative way of sizing temperature levels in each DH system according to the listed methodology and the designer's preference.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4954
Author(s):  
Mohammad AlHashmi ◽  
Gyan Chhipi-Shrestha ◽  
Kh Md. Nahiduzzaman ◽  
Kasun Hewage ◽  
Rehan Sadiq

Rapid population growth has led to significant demand for residential buildings around the world. Consequently, there is a growing energy demand associated with increased greenhouse gas (GHG) emissions. The residential building energy demand in arid countries such as Saudi Arabia is supplied with fossil fuel. The existing consumption pattern of fossil fuels in Saudi Arabia is less sustainable due to the depletion of fossil fuel resources and resulting environmental impacts. Buildings built in hot and arid climatic conditions demand high energy for creating habitable indoor environments. Enormous energy is required to maintain a cool temperature in hot regions. Moreover, climate change may have different impacts on hot climatic regions and affect building energy use differently. This means that different building interventions may be required to improve the performance of building energy performance in these geographical regions, thereby reducing the emissions of GHGs. In this study, this framework has been applied to Saudi Arabia, a hot and arid country. This research proposes a community–government partnership framework for developing low-carbon energy in residential buildings. This study focuses on both the operational energy demand and a cost-benefit analysis of energy use in the selected geographical regions for the next 30 years (i.e., 2050). The proposed framework primarily consists of four stages: (1) data collection on energy use (2020 to 2050); (2) setting a GHG emissions reduction target; (3) a building intervention approach by the community by considering cost, energy, and GHG emissions using the Technique for Order of Performance by Similarity to the Ideal Solution (TOPSIS) to select the best combinations in each geographical region conducting 180 simulations; and (4) a clean energy approach by the government using grey relational analysis (GRA) to select the best clean energy system on the grid. The clean energy approach selected six different renewable power generation systems (i.e., PV array, wind turbine, hybrid system) with two storage systems (i.e., battery bank and a combination of electrolyte, fuel cell, and hydrogen tank storage). This approach is designed to identify the best clean energy systems in five geographical regions with thirty scenario analyses to define renewable energy-economy benefits. This framework informs through many engineering tools such as residential building energy analysis, renewable energy analysis, multi-criteria decision analysis (MCDA) techniques, and cost-benefit analysis. Integration between these engineering tools with the set of energy policies and public initiatives is designed to achieve further directives in the effort to reach greater efficiency while downsizing residential energy demands. The results of this paper propose that a certain level of cooperation is required between the community and the government in terms of financial investments and the best combinations of retrofits and clean energy measures. Thus, retrofits and clean energy measures can help save carbon emissions (enhancing the energy performance of buildings) and decrease associated GHG emissions, which can help policy makers to achieve low-carbon emission communities.


Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 642
Author(s):  
Mark Kyeredey Ansah ◽  
Xi Chen ◽  
Hongxing Yang

Reducing the lifecycle energy use of buildings with renewable energy applications has become critical given the urgent need to decarbonize the building sector. Multi-objective optimizations have been widely applied to reduce the operational energy use of buildings, but limited studies concern the embodied or whole lifecycle energy use. Consequently, there are issues such as sub-optimal design solutions and unclear correlation between embodied and operational energy in the current building energy assessment. To address these gaps, this study integrates a multi-objective optimization method with building energy simulation and lifecycle assessment (LCA) to explore the optimal configuration of different building envelopes from a lifecycle perspective. Major contributions of the study include the integrated optimization which reflects the dynamics of the whole lifecycle energy use. Insights from the study reveal the optimal configuration of PV and composite building façades for different regions in sub-Saharan Africa. The lifecycle energy use for the optimized building design resulted in 24.59, 33.33, and 36.93% energy savings in Ghana, Burkina Faso, and Nigeria, respectively. Additionally, PV power generation can efficiently cover over 90% of the total building energy demand. This study provides valuable insights for building designers in sub-Saharan Africa and similar areas that minimize lifecycle energy demand.


Author(s):  
N. Fumo ◽  
P. J. Mago ◽  
L. M. Chamra

Cooling, Heating and Power (CHP) systems are a form of distributed generation that uses internal combustion prime-power engines to generate electricity while recovering heat for other uses. CHP is a promising technology for increasing energy efficiency through the use of distributed electric and thermal energy recovery-delivery systems at or near end-user sites. Although this technology seems to be economically feasible, the evaluation and comparison of CHP systems cannot be restricted to economical considerations only. Standard economic analysis, such as life cycle economic analysis, does not take in consideration all the benefits that can be obtained from this technology. For this reason, several aspects to perform a non-conventional evaluation of CHP systems have to be considered. Among the aspects to be included in a non-conventional evaluation are: power reliability, power quality, environmental quality, energy-efficient buildings, fuel source flexibility, brand and marketing benefits, protection from electric rate hikes, and benefits from promoting energy management practices. Some benefits of these non-economical evaluations can be transferred into an economic evaluation but others give intangible potential to the technology. This paper focus on a non-conventional evaluation based on energy-efficient buildings, which is associated to energy conservation and improvement of the building energy performance rating for government energy programs like Energy Star and Leadership in Energy and Environmental Design (LEED). Results show that the use of CHP systems could improve the Energy Star Rating in more than 50 points. The Energy Star Rating is significant on the LEED Rating as a building can score up to 10 points of the 23 available in the Energy & Atmosphere category on energy efficiency alone. As much as 8 points can be obtained in this category due to the Energy Star rating increment from the use of CHP systems. Clearly the use of CHP systems will help building owners to reach the benefits from these energy programs while improving the overall energy use and energy cost.


2021 ◽  
Author(s):  
Pouriya Jafarpur

The study describes the results of climate change impact assessment on building energy use in Toronto, Canada. Accordingly, three future weather data sets are generated and applied to the energy simulation of 16 building prototypes. Both statistical and dynamical downscaling techniques are used to generate the future weather files. The results indicate an average decrease for the future in the range of 18-33% in heating EUI, and an average increase of 16-126% in cooling EUI, depending on the baseline climate and building type. In addition, the GHG emissions for each building model are presented. It is concluded that the application of future weather files for building performance simulation leads to a better quantification of building energy demand in the future than a historical weather file. Furthermore, the results demonstrate the need to modify and adapt existing building modelling regulations and to plan future building according to the future climate.


2021 ◽  
Vol 2042 (1) ◽  
pp. 012019
Author(s):  
G Peronato ◽  
R Boghetti ◽  
J H Kämpf

Abstract Aggregated building energy demand is a useful indicator for urban energy planning. It can be used by planners and decision-makers to identify clusters of high energy demand in a given urban area and efficiently plan, for example, district heating networks. Various data sources exist at the pan-European level describing land use and built areas. Combined with statistical data, such maps have been used in previous research for estimating building energy performance aggregated at the hectare level, using engineering assumptions. In this paper, we show that large-scale land-use maps alone can be used for predicting annual building energy demand with an accuracy comparable to the one of previous engineering models. We hence present a preliminary method based on Convolutional Neural Networks at different spatial resolutions. The resulting model was trained and tested in an area of about 170 km1 in Geneva (Switzerland) using a local annual heating demand dataset comprising 16239 buildings. On a 300-m aggregation tile, the obtained mean error (14.3%) is significantly reduced compared to the one of a simple linear model (37.2%). Using solely land-use data, we also achieve similar results for a 100-m tile as those of an engineering model from the literature.


2021 ◽  
pp. 1420326X2110501
Author(s):  
Shambalid Ahady ◽  
Nirendra Dev ◽  
Anubha Mandal

Buildings are significant consumers of energy and producer of greenhouse gases worldwide, and serious efforts have been put into designing energy-efficient buildings. Significant technological advances have been achieved in developed countries; however, advances have rarely been adopted in developing countries like Afghanistan. Such trends emerge from the lack of research in designing energy-efficient buildings to local conditions, practices and materials. This research focused on building energy modelling and simulation to evaluate the energy performance impact of different shading and orientation. The research design follows a case study over an actual seven-storey multi-apartment residential building in the city of Mazar-I-Sharif, Afghanistan, using primary field data and dynamic simulation. Findings demonstrated that neighbouring structures have a positive correlation with a cooling demand. Meanwhile, south is the optimal orientation to face the building's glazed façade, saving up to 7.4% of cooling and 9.7% of heating energy. Moreover, movable shading devices installed on the building's openings in the summer season reduce the building energy load up to 19%, with a total energy cost reduction of AFN. 188,448 ($2447.37 US) annually. The study underlines the vast research scope in customizing building designs to Afghanistan's climatic conditions and other developing countries, thus contributing to buildings’ sustainability.


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