scholarly journals Office Building Tenants’ Electricity Use Model for Building Performance Simulations

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5541
Author(s):  
Andrea Ferrantelli ◽  
Helena Kuivjõgi ◽  
Jarek Kurnitski ◽  
Martin Thalfeldt
Keyword(s):  
Energy Use ◽  
Office Building ◽  
Building Performance ◽  
Substantial Portion ◽  
Critical Importance ◽  
Simple Method ◽  
Heating And Cooling ◽  
Electricity Use ◽  
The Impact

Large office buildings are responsible for a substantial portion of energy consumption in urban districts. However, thorough assessments regarding the Nordic countries are still lacking. In this paper we analyse the largest dataset to date for a Nordic office building, by considering a case study located in Stockholm, Sweden, that is occupied by nearly a thousand employees. Distinguishing the lighting and occupants’ appliances energy use from heating and cooling, we can estimate the impact of occupancy without any schedule data. A standard frequentist analysis is compared with Bayesian inference, and the according regression formulas are listed in tables that are easy to implement into building performance simulations (BPS). Monthly as well as seasonal correlations are addressed, showing the critical importance of occupancy. A simple method, grounded on the power drain measurements aimed at generating boundary conditions for the BPS, is also introduced; it shows how, for this type of data and number of occupants, no more complexities are needed in order to obtain reliable predictions. For an average year, we overestimate the measured cumulative consumption by only 4.7%. The model can be easily generalised to a variety of datasets.

scholarly journals Data-driven analysis of electricity use for office buildings: a Norwegian case study

2021 ◽  
Vol 246 ◽  
pp. 04005
Author(s):  
Yuemin Ding ◽  
Yiyu Ding ◽  
Natasa Nord
Keyword(s):  
Energy Use ◽  
Polynomial Regression ◽  
Primary Energy ◽  
Office Building ◽  
Data Driven ◽  
Monitoring And Control ◽  
Improve Energy Efficiency ◽  
Electricity Use ◽  
And Control ◽  
The Impact

Buildings are major consumers of primary energy and main contributors to carbon emission. To improve energy efficiency, it is essential to understand the characteristics of energy use in buildings. This study uses an in-use office building with digital systems for monitoring and control in Trondheim, Norway, as the study case. Based on data collected from this office building, a data-driven analysis was conducted to capture the characteristics of electricity use of different parts in the office building. The approaches used in this study included statistical analysis and polynomial regression. The impact of occupancy level on the total electricity use, the electricity use in office areas, and that in corridors & meeting rooms was also studied. The hourly electricity use profiles were obtained for ventilation fans and the cantina. In the end, the electricity use characteristics and existing issues in this office building were discussed.

scholarly journals Impact of office tenants’ electricity use on the cost-optimal solutions in a cold climate

2021 ◽  
Vol 246 ◽  
pp. 05001
Author(s):  
Helena Kuivjõgi ◽  
Liina Laas ◽  
Andrea Ferrantelli ◽  
Martin Thalfeldt
Keyword(s):  
Input Data ◽  
Energy Use ◽  
Energy Performance ◽  
Cold Climate ◽  
Office Building ◽  
Optimal Solutions ◽  
Pv System ◽  
Electricity Use ◽  
The Cost ◽  
The Impact

The buildings’ energy performance requirements in Estonia are based on cost-optimality analysis according to the EPBD and pre-defined building performance simulation (BPS) input data from EN 16798-1:2019. Previous studies have shown that the real electricity use of office building tenants differs from the currently used input data in BPS in Estonia – less in total energy use, but more in the shape of the profiles. The aim of this work is to investigate what is the impact of these differences on the cost-optimal solutions, which are identified based on BPS and the self-consumption of the photovoltaic panel (PV) systems. This study describes the energy performance and construction cost analysis of a new office building in Tallinn, Estonia. BPS based on the EN 16798-1 and a model derived from measurements in a real building were conducted and cost-optimal building solutions identified. The variables were building envelope insulation thickness, air handling unit size and effectiveness, electrical lighting control principles and PV system nominal power. The calculated energy use of the building with the two different sets of input data differed significantly. However, the set of cost-optimal solutions identified with EN 16798-1:2019 input data had minor differences from the set of solutions identified with the more realistic model. The decrease of net present value over 20-year period for cost-optimal solution was 11-14 €/m2 compared to the designed building.The realistic office tenants’ electricity model increased the calculated self-consumption of the PV system from 95% to 100%.

Numerical Modelling of a District Scale Groundwater Heat Pump Operation: Case Study from Colchester, UK

2021 ◽  
Author(s):  
Taha Sezer ◽  
Abubakar Kawuwa Sani ◽  
Rao Martand Singh ◽  
David P. Boon
Keyword(s):  
Large Scale ◽  
District Level ◽  
Thermal Plume ◽  
Injection Wells ◽  
Term Operation ◽  
Heating And Cooling ◽  
Groundwater Heat Pump ◽  
The Impact

<p>Groundwater heat pumps (GWHP) are an environmentally friendly and highly efficient low carbon heating technology that can benefit from low-temperature groundwater sources lying in the shallow depths to provide heating and cooling to buildings. However, the utilisation of groundwater for heating and cooling, especially in large scale (district level), can create a thermal plume around injection wells. If a plume reaches the production well this may result in a decrease in the system performance or even failure in the long-term operation. This research aims to investigate the impact of GWHP usage in district-level heating by using a numerical approach and considering a GWHP system being constructed in Colchester, UK as a case study, which will be the largest GWHP system in the UK. Transient 3D simulations have been performed pre-construction to investigate the long-term effect of injecting water at 5°C, into a chalk bedrock aquifer. Modelling suggests a thermal plume develops but does not reach the production wells after 10 years of operation. The model result can be attributed to the low hydraulic gradient, assumed lack of interconnecting fractures, and large (>500m) spacing between the production and injection wells. Model validation may be possible after a period operational monitoring.</p>

scholarly journals A Complementary Approach to Traditional Energy Balances for Assessing Energy Efficiency Measures in Final Uses: The Case of Space Heating and Cooling in Argentina

2020 ◽  
Vol 12 (16) ◽  
pp. 6563
Author(s):  
Roque G Stagnitta ◽  
Matteo V Rocco ◽  
Emanuela Colombo
Keyword(s):  
Energy Consumption ◽  
Energy Use ◽  
Primary Energy ◽  
Embodied Energy ◽  
Space Heating ◽  
Output Analysis ◽  
Final Energy ◽  
Heating And Cooling ◽  
Energy Balances ◽  
The Impact

Energy balances have been historically conceived based on a supply-side perspective, providing neither detailed information about energy conversion into useful services nor the effects that may be induced by the application of policies in other sectors to energy consumption. This article proposes an approach to a thorough assessment of the impact of efficiency policies on final energy uses, focusing on residential space heating and cooling, and capable of: (1) quantifying final useful services provided and (2) accounting for the global impact of efficiency policies on final energy use, taking advantage of Input–Output analysis. This approach is applied in five cities of Argentina. Firstly, the quantity of energy service provided (i.e., level of thermal comfort) for each city is evaluated and compared with the defined target. It is found out that heating comfort is guaranteed approximately as established, whereas in the cooling case the provision is twice the established level. Secondly, primary energy consumption of heating and cooling services is evaluated before and after different efficiency improvement policies. The results show that the major primary energy saving (52%) is obtained from the upgrading appliances scenario and reflect the importance of accounting for embodied energy in goods and services involved in interventions.

Evaluating Supply Chain Energy Use in a Smart Grid Paradigm

2011 ◽  
Author(s):  
Amip J. Shah ◽  
Kiara Corrigan
Keyword(s):  
Supply Chain ◽  
Value Chain ◽  
Energy Use ◽  
Small Subset ◽  
Time Data ◽  
Cost Structures ◽  
Energy Footprint ◽  
Electricity Use ◽  
Geographic Diversity

A key paradigm shift resulting from the intersection of the information technology (IT) and utility sectors is the availability of real-time data regarding energy use across different industries. Historically, ascertaining the energy costs across the value chain of a given product or service was a laborious and expensive task, requiring many months of data collection; several proxies or approximations for cases where measured data might not be cost-effectively available; and even then, the resulting energy footprint could have significant uncertainty based on time-of-measurement, geographic diversity of manufacturing sites, etc. As dynamic energy pricing begins to take hold and environmental externalities begin to be priced into existing cost structures, the ability to optimize a given value chain for minimal energy use becomes increasingly attractive. In this paper, we discuss an approach for leveraging dynamically available data alongside historical n-tier supply chain models to avail the ability for such optimization. The approach is illustrated for the case study of a computer manufacturer, where we find that metering electricity use at a small subset of sites can allow for a reasonable estimate of the total energy use across the supply chain.

Roof Cover Impact on Cooling Energy Use of Office Buildings

2014 ◽  
Author(s):  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Simulation Analysis ◽  
Calculation Model ◽  
Office Building ◽  
Climate Zones ◽  
Building Energy Use ◽  
Detailed Simulation ◽  
Simplified Calculation ◽  
The Impact

This paper analyzes the impact of roof covers on office building energy use for representative US climate zones. In particular, the study presented in the paper investigates the potential annual cooling energy use savings that roof covers could provide using whole-building simulation analysis to evaluate the performance of a 2-story office building in five US locations. Three parameters of the roof covers including their size, height, and transmittance, are considered in the analysis. The simulation results indicate that while roof covers had similar affects on buildings in all climate zones, their impact in reducing cooling energy usage is different and is more pronounced in cooler climates. Specifically, roof covers could potentially achieve cooling energy savings of up to: 25% in Houston, 33% in Atlanta, 31% in Nashville, 38% in Chicago, and 41% in Madison. Based on the detailed simulation analysis results, a simplified calculation model is developed to help the estimation of cooling energy savings as a function of the roof cover size, height, and transmittance.

Analysis of Electrical Energy Savings From Daylighting Through Skylights

Solar Energy ◽  
2005 ◽  
Author(s):  
Abdelkarim Nemri ◽  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Simulation Analysis ◽  
Control Strategies ◽  
Electrical Energy ◽  
Office Building ◽  
Analysis Tool ◽  
Energy Saving Potential ◽  
Lighting Energy ◽  
The Impact

This paper provides a simplified analysis tool to assess the energy saving potential of daylighting for commercial buildings through skylights. Specifically, the impact of daylighting is investigated for various fenestration opening sizes, glazing types, control strategies, and geographic locations. A top floor of a prototypical office building has been considered in the analysis. The results obtained for the office building can be applied to other types of buildings such as retails stores, schools, and warehouses. Based on the simulation analysis results, it was determined that skylight to floor ratio more than 0.3 does not affect significantly the lighting energy savings. An optimum value of skylight to floor area ratio was found to be 0.2 to minimize the annual total building energy use.

scholarly journals Impact of Typical Faults Occurring in Demand-controlled Ventilation on Energy and Indoor Environment in a Nordic Climate

2020 ◽  
Vol 172 ◽  
pp. 09006
Author(s):  
Kamilla Heimar Andersen ◽  
Sverre B. Holøs ◽  
Aileen Yang ◽  
Kari Thunshelle ◽  
Øystein Fjellheim ◽  
...  
Keyword(s):  
Indoor Environment ◽  
Energy Use ◽  
Qualitative Interviews ◽  
Building Performance ◽  
Local Approach ◽  
Performance Simulation ◽  
Building Performance Simulation ◽  
Controlled Ventilation ◽  
Demand Controlled Ventilation ◽  
The Impact

This study evaluates typical faults occurring in demand-controlled ventilation (DCV) system and the impact on three output results: energy use, thermal comfort, and indoor air quality. The methodologies used in this study were qualitative interviews of selected Norwegian Heating Ventilation Air Condition (HVAC) system experts and numerical modeling using the building performance simulation tool IDA ICE. The faults deduced from the qualitative interviews were modeled as the fault's different consequences to account for a large variety of faults. With a Norwegian school classroom as a case study, a local approach applying a one-at-a-time (OAT) simulation was used to perform an analysis of the extreme fault conditions that can occur. The results from the fault modeling demonstrated that greater attention is needed to avoid faults in the HVAC systems due to its impact on the indoor environment quality and energy efficiency of buildings.

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