Uncertainty of Daylighting Performance of Manual Solar Shades and its Influence on Lighting Energy

2020 ◽  
pp. 77-84
Author(s):  
Jian Yao ◽  
LiYi Chen ◽  
Wu Jin

Occupant behaviour significantly influences building energy consumption. This paper is devoted to studies the uncertainty of daylighting performance and lighting energy of manual solar shades on the south facade. A developed stochastic model for manual solar shades was used for co-simulation by BCVTB. Results show that uncertainty of shade action was not suppressed by the shade behaviour model with very weak relationship between different simulation outputs. Uncertainty of daylighting performance is 15.08 % while lighting energy uncertainty is 10.38 %. Although this level of energy uncertainty is not very significant, it influences economic analysis of manual solar shades and therefore, occupant related uncertainty should be taken into consideration when predicting energy performance of manual shades.

Author(s):  
Heangwoo Lee ◽  
Janghoo Seo

While previous research has shown the use of attachable air-caps on windows to efficiently reduce a building’s energy consumption, the air-caps considered had to be attached to the entire window’s surface, thus limiting the occupants’ view and creating the inconvenience of needing to detach and attach the air-caps. In this study, a window-mounted air-cap roller module using Velcro tape that may be easily attached, detached, and rolled up or down was developed and performance tested in a full-scale test bed. It was found that as the area of the air-caps attached on a window increased, the required indoor lighting energy increased. However, the window insulation improved, thus reducing the cooling and heating energy needed. Attaching the air-caps to the entire window surface effectively reduced the building’s energy consumption, but views through the window may be disturbed. Thus, the developed window-mounted air-caps enable an occupant to reduce the building energy consumption and maintain their view according to their need. The findings of this study may contribute to a reduction in building energy consumption without sacrificing a pleasant indoor environment. Further studies may be needed to verify their efficacy under varying indoor and outdoor conditions.


Author(s):  
Guanjing Lin ◽  
David E. Claridge

Commissioning services have proven successful in reducing building energy consumption, but the optimal energy performance obtained by commissioning may subsequently degrade. Automated Building Commissioning Analysis Tool (ABCAT), which combines a calibrated simulation with diagnostic techniques, is a simple and cost efficient tool that can help maintain the optimal building energy performance after building commissioning. It can continuously monitor whole building energy consumption, warn operation personnel when an HVAC system problem has increased energy consumption, and assist them in identifying the possible cause(s) of the problem. This paper presents the results of a retrospective implementation of ABCAT on five buildings, each of which has at least three years of post-commissioning daily energy consumption data, on the Texas A&M University campus. The methodology of ABCAT is reviewed and the implementation process of ABCAT on one building is specifically illustrated. Eighteen faults were detected in 15 building-years of consumption data with a defined fault detection standard. The causes of some of the detected faults are verified with historical documentation. The remaining fault diagnoses remain unconfirmed due to data quality issues and incomplete information on maintenance performed in the buildings.


2019 ◽  
Vol 111 ◽  
pp. 04027
Author(s):  
Aymeric Novel ◽  
Francis Allard ◽  
Patrice Joubert

Energy performance guarantee projects aim at achieving a given energy consumption in real life conditions. Building energy consumption monitoring during operation phase often reveals that energy consumption is sensitive to building spaces use and systems operation quality, especially for buildings with high energy performance characteristics [7]. Other investigations show the impact of building users’ behaviour on energy consumption [28]. These factors must be added to climate factors for energy consumption prediction during operation phase. Number of factors and possible combinations is very high. Building energy modeling is limited regarding this issue and metamodeling has been used to solve this problem [25]. We developed metamodels that are polynomial functions using D-optimal design of experiment (DOE) approach. Such metamodels can become operational tools to use in the IPMVP framework, associated with a M&V plan. This paper shows the application of the method on a cultural building that comprises numerous systems and usages. We obtain a reliable metamodel of the energy consumption as a function of climate, operation, and space use factors. which meets IPMVP [11] and ASHRAE Guideline 14 [3] modeling uncertainties criteria. We also determine the global uncertainty resulting from predictors’ uncertainties propagation and modelling uncertainty associated with the metamodel.


2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Atefeh Mohammadpour ◽  
Mohammad Mottahedi ◽  
Shideh Shams Amiri ◽  
Somayeh Asadi ◽  
David Riley ◽  
...  

Building energy modeling is essential to estimate energy consumption of buildings. Predicting building energy consumption benefits the owners, designers, and facility managers by enabling them to have an overview of building energy consumption and can help them to determine building energy performance during the design phase. This paper focuses on two different shapes of commercial building, H and rectangle to estimate energy consumption in buildings in three different climate zones, cold, hot-humid, and mixed-humid. To address this, DOE-2 building simulation software was used to build and simulate individual commercial building configurations that were generated using Monte Carlo simulation techniques. Ten thousand simulations for each building shape and climate zone were conducted to develop a comprehensive dataset covering the full range of design parameters. 


Author(s):  
Rasool Koosha ◽  
Fatemeh Shahsavari

Abstract Recent literature on building energy performance simulation leans toward implementing uncertainty analysis (UA), instead of deterministic solutions, to handle ever-existing and pivotal uncertainties in building design decision-making process. Variations in weather temperature, degradation of building envelope material properties over time, and random behavior of occupants, among all, are the key sources of uncertainty in building energy consumption predictions. The UA couples to the sensitivity analysis (SA) to identify the most influential inputs on the uncertainties of the building energy consumption. This paper describes a newly-developed UA and SA predictive tool for building energy performance simulations. Energy performance simulations are based on a resistance-capacitance thermal model for the building. For a hypothetical residential building in College Station, Texas, USA, the present work describes and compares predicted probability distribution and sensitivity indexes produced by the UA-SA tool using a transient (dynamic) response analysis (TRA) and static response analysis (SRA). For brevity, the analysis considers uncertainty only for the exterior walls’ parameters including thickness, thermal conductivity, heat transfer coefficient, density, and heat capacity; i.e., a five-dimensional problem is solved. Compared to the TRA, predictions from the SRA underestimate the annual energy consumption up to 30%; however, SRA is significantly faster. Nonetheless, sensitivity indexes from the SRA and TRA closely match.


2019 ◽  
Vol 111 ◽  
pp. 04045
Author(s):  
Marko G. Ignjatović ◽  
Bratislav D. Blagojević ◽  
Mirko M. Stojiljković ◽  
Aleksandar S. Anđelković ◽  
Milena B. Blagojević ◽  
...  

One of the possible ways to improve balance between building energy consumption and occupant thermal comfort in existing buildings is to use simulation-assisted operation of HVAC systems. Simulation-assisted operation can be formulated as a type of operation that implements knowledge of future disturbance acting on the building and that enables operating the systems in such a way to fulfill given goals, which in nature can often be contradictory. The most important future conditions on building energy consumption are weather parameters and occupant behavior and expectations of thermal environment. In order to achieve this type of operation, optimization methods must be applied. Methodology to create HVAC system operation strategies on a daily basis is presented. Methodology is based on using building energy performance simulation software EnergyPlus, available weather data, global sensitivity analysis, and custom developed software with particle swarm optimization method applied over the moving horizon. Global sensitivity analysis is used in order to reduce number of independent variables for the optimization process. The methodology is applied to office part of real combined-type building located in Niš, Serbia. Use of sensitivity analysis shows that the reduced number of independent variables for the optimization would lead to similar thermal comfort and energy consumption, with significant computer runtime reduction.


2019 ◽  
Vol 11 (23) ◽  
pp. 6872 ◽  
Author(s):  
Pathomthat Chiradeja ◽  
Atthapol Ngaopitakkul

The building envelope has a direct impact on the overall energy consumption of a building. Thus, an improvement in the building envelope using energy-efficient material can yield the desired energy performance. This study is based on the materials and compositions used in building envelopes in compliance with the building energy code of Thailand. The building under study is an educational building located in Bangkok, Thailand. Both the energy and the economic aspects of retrofitted building envelopes are discussed in this study. The energy performance was evaluated by calculating the thermal transfer value and whole building energy consumption using the building energy code (BEC) software. The simulation was done under the assumption that the building envelope in the case study building was retrofitted with different materials and compositions. The study determines the feasibility of retrofitting buildings using energy-efficient material by utilizing the discounted payback period and internal rate of return (IRR) as indicators. The results show that retrofitted building envelopes in every case can reduce the whole building energy consumption. In the best envelope configuration, energy consumption can decrease by 65%. In addition, the economic potential is also high, with an IRR value of approximately 15% and a payback period of 23 less than nine years. These finding indicate that a building envelope made with energy-efficient material can achieve good results for both energy performance and economic feasibility.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1181 ◽  
Author(s):  
Bo Rang Park ◽  
Jongin Hong ◽  
Eun Ji Choi ◽  
Young Jae Choi ◽  
Choonyeob Lee ◽  
...  

The present study sets out to review the thermal and optical properties of electrochromic windows (ECWs) through an analysis of the improvement in the energy performance of a building resulting from their application. The performance analysis was based on the change in the room temperature according to the solar transmittance and the orientation of the ECWs, the energy consumptions of the building’s heating/cooling systems, and that of the building’s lighting according to the visible light transmittance (VLT). To achieve this, the Quick Energy Simulation Tool (eQUEST), a building energy interpretation program, was used. The solar heat gain coefficient (SHGC) of the ECWs was found to be significantly reduced. This had the effect of lowering the room temperature in summer, such that the effect on the summer cooling energy consumption was also remarkable. However, with a reduction in the VLT, the lighting energy consumption increased. The net result of the changes in the heating/cooling and lighting energy consumptions was a reduction of about 11,207 kWh/yr (8.89%). The ECWs were found to realize a greater reduction in a building’s energy consumption than was possible with windows glazed with low-E coated glass.


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