scholarly journals Architectural Sustainability on the Impacts of Different Air-Conditioning Operational Profiles and Temperature Setpoints on Energy Consumption: Comparison between Mosques with and Without HVLS Fan in the City Center Mosques

2021 ◽  
Vol 21 (2) ◽  
pp. 19-38
Author(s):  
Nur Amalina Syairah Mohamed ◽  
Zalina Shari ◽  
Nur Dalilah Dahlan ◽  
Ibiyeye Aminat Idowu
Keyword(s):  
Energy Consumption ◽  
Energy Cost ◽  
Air Conditioning ◽  
High Volume ◽  
Energy Performance ◽  
Energy Impact ◽  
Operational Profile ◽  
Operational Characteristics ◽  
Daily Prayer ◽  
The City

The use of air-conditioning (AC) in conjunction with high-volume, low-speed (HVLS) fan has become a trend in retrofitted mosque buildings in Malaysia to improve thermal comfort conditions. However, the energy impact of operating AC and HVLS fan simultaneously is unknown. This study compares the annual energy consumptions between mosques with and without HVLS fan installed and investigates the optimum temperature setpoints and operational profile to improve the mosques' energy efficiency. The comparison using the Building Energy Index (BEI) did not clearly show the superiority between the two groups in terms of energy performance. The study found that both studied mosques could produce around 1-4.9% energy reduction when the AC temperature setpoint was increased by 1˚C and could result in the highest cost-saving of about 4.9% when the temperature was set at 27˚C. A 30-minute AC operation during each daily prayer, except Subuh, could save between 14.8-16.7% annual energy consumption and about 15.15-16.6% annual energy cost. The paper concludes that the selection of 24-27˚C temperature setpoints with a 30-minute AC operational profile during prayers time with consideration Friday prayers and Ramadhan activities produced 18.4-20.6% savings in energy cost. This study calls for reevaluations of AC temperature setpoints configuration standards and operational characteristics in mosque buildings to reduce the buildings' energy consumption. This paper contributes to the development of future energy standards for mosque designs and operations in Malaysia.

scholarly journals Assessing the energy performance of VAV and VRF air conditioning systems in an office building located in the city of Florianópolis

2020 ◽  
Vol 20 (2) ◽  
pp. 261-283
Author(s):  
Vanessa Cavalcanti Paes Duarte ◽  
Ana Paula Melo ◽  
Roberto Lamberts
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Energy Use ◽  
Load Ratio ◽  
Energy Performance ◽  
Office Building ◽  
Coefficient Of Performance ◽  
Partial Load ◽  
Air Conditioning Systems ◽  
The City

Abstract The objective of this study is to analyze the energy performance of two types of water-cooled air conditioning systems, variable air volume (VAV) and variable refrigerant flow (VRF), in terms of their cooling energy use through building simulation. These systems were designed to operate in an office building located in the city of Florianópolis, Brazil. The analysis involved the application of two building use schedules: a) constant and b) variable. Moreover, an analysis of the coefficient of performance (COP) and partial load ratio (PLR), and the percentage of operating hours for each range of cooling COP and PLR for each air conditioning system, allowed the system cooling efficiency to be assessed and the results to be related to the annual energy consumption. The coefficient of performance of VAV and VRF is 6.7 and 5.0, respectively, but the VRF system presented the lowest energy consumption for both schedules. The difference in the cooling energy consumption values for the VRF and VAV systems, for the variable schedule compared with the constant schedule, is mainly influenced by the partial load performance during the hottest period of the year.

scholarly journals Hybrid-Model-Based Deep Reinforcement Learning for Heating, Ventilation, and Air-Conditioning Control

2021 ◽  
Vol 8 ◽  
Author(s):  
Huan Zhao ◽  
Junhua Zhao ◽  
Ting Shu ◽  
Zibin Pan
Keyword(s):  
Reinforcement Learning ◽  
Energy Consumption ◽  
Hybrid Model ◽  
Learning Process ◽  
Energy Cost ◽  
Air Conditioning ◽  
Electricity Price ◽  
Learning Efficiency ◽  
Model Based ◽  
Model Free

Buildings account for a large proportion of the total energy consumption in many countries and almost half of the energy consumption is caused by the Heating, Ventilation, and air-conditioning (HVAC) systems. The model predictive control of HVAC is a complex task due to the dynamic property of the system and environment, such as temperature and electricity price. Deep reinforcement learning (DRL) is a model-free method that utilizes the “trial and error” mechanism to learn the optimal policy. However, the learning efficiency and learning cost are the main obstacles of the DRL method to practice. To overcome this problem, the hybrid-model-based DRL method is proposed for the HVAC control problem. Firstly, a specific MDPs is defined by considering the energy cost, temperature violation, and action violation. Then the hybrid-model-based DRL method is proposed, which utilizes both the knowledge-driven model and the data-driven model during the whole learning process. Finally, the protection mechanism and adjusting reward methods are used to further reduce the learning cost. The proposed method is tested in a simulation environment using the Australian Energy Market Operator (AEMO) electricity price data and New South Wales temperature data. Simulation results show that 1) the DRL method can reduce the energy cost while maintaining the temperature satisfactory compared to the short term MPC method; 2) the proposed method improves the learning efficiency and reduces the learning cost during the learning process compared to the model-free method.

scholarly journals Hygrothermal performance of the building envelope with low environmental impact: case of a hemp concrete envelope

2021 ◽  
Vol 2069 (1) ◽  
pp. 012006
Author(s):  
A Kabore ◽  
W Maref ◽  
C O Plamondon
Keyword(s):  
Environmental Impact ◽  
Air Conditioning ◽  
Energy Performance ◽  
Building Envelope ◽  
Glass Wool ◽  
Mould Growth ◽  
Cement Block ◽  
Hygrothermal Performance ◽  
The City

Abstract This document is a case study of hemp-based materials integrated into the building envelope for African and North American’s applications. The objective is to evaluate the energy performance of hemp concrete for construction in Montreal, Canada, where heating predominates and in Dori, Burkina Faso, where air conditioning predominates. The effect of thermal and hygrothermal comfort of hemp concrete, glass wool, cement block and compressed earth brick walls were simulated to quantify the benefits on overheating during the hottest months for the city of Dori and the risk of mould growth in the walls of the building in winter for the city of Montreal.

Impacts of Air Conditioning Equipment Sizing on Energy Performance of US Office Buildings

2021 ◽  
pp. 1-24
Author(s):  
Franklin Chiu ◽  
Moncef Krarti
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Energy Performance ◽  
Office Buildings ◽  
Peak Demand ◽  
Capital Costs ◽  
Wide Range ◽  
Ac Systems ◽  
Equipment Sizing ◽  
Conditioning Equipment

Abstract The paper summarizes the results of a systematic and comprehensive analysis to investigate the impacts of inadequate sizing air conditioning (AC) systems on the overall energy consumption of medium and large office buildings located in representative US cities. The effects of proper sizing on the overall and disaggregated AC systems are evaluated in terms of energy consumption, peak demand, equipment run-time, and indoor thermal comfort. The presented analysis covers the performance a wide range of AC equipment components that serve US office buildings including packaged rooftop units as well as central cooling plants. The analysis results indicate that oversizing penalties can be significant on the annual energy consumption and electrical peak demand as well as capital costs for both medium and large office buildings. In particular, the reliance on simplified calculation methods and rules-of-thumb to determine equipment capacities can lead to significantly oversizing AC systems for office buildings in the vast majority of US climates and can result in increases of annual energy consumption and electrical peak demand of up to 29%. Moreover, oversizing increases capital costs required for air conditioning office buildings and extends cycling periods and associated structural stresses and failures of AC equipment.

scholarly journals Vehicle Electrification Impacts on Energy Consumption for Different Connected-Autonomous Vehicle Scenario Runs

2019 ◽  
Vol 11 (1) ◽  
pp. 9
Author(s):  
Ehsan Sabri Islam ◽  
Ayman Moawad ◽  
Namdoo Kim ◽  
Aymeric Rousseau
Keyword(s):  
Energy Consumption ◽  
Travel Behavior ◽  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Transportation System ◽  
Regional Energy ◽  
Energy Impact ◽  
Potential Factors ◽  
The Impact ◽  
The City

Transportation system simulation is a widely accepted approach to evaluate the impact of transport policy deployment. In developing a transportation system deployment model, the energy impact of the model is extremely valuable for sustainability and validation. It is expected that different penetration levels of Connected-Autonomous Vehicles (CAVs) will impact travel behavior due to changes in potential factors such as congestion, miles traveled, etc. Along with such impact analyses, it is also important to further quantify the regional energy impact of CAV deployment under different factors of interest. The objective of this paper is to study the energy consumption of electrified vehicles in the future for different penetration levels of CAVs deployment in the City of Chicago. The paper will further provide a statistical analysis of the results to evaluate the impact of the different penetration levels on the different electrified powertrains used in the study.

scholarly journals Determining the Modelling Input Parameters for Heating, Ventilation, and Air Conditioning Systems in New Zealand Commercial Buildings

2021 ◽  
Author(s):  
◽  
Anthony Gates
Keyword(s):  
Energy Consumption ◽  
New Zealand ◽  
Air Conditioning ◽  
Energy Performance ◽  
Hvac Systems ◽  
Commercial Buildings ◽  
Hvac System ◽  
Input Parameters ◽  
Parameter Values ◽  
The Ideal

<p>Template energy calculation models that have been produced by the Building Energy End-use Study (BEES) team are used to quickly and reliably model commercial buildings and calculate their energy performance. The template models contain standardised equipment, lighting, and occupancy loads; cooling and heating requirements are calculated using an ideal loads air system. Using seven buildings, Cory et al. 2011a have demonstrated that the template models have the potential to closely match the monthly energy performance of detailed (individually purpose built) models and the real buildings. Three of these models were within the ±5% acceptable tolerance to be considered calibrated. The four template models that were not within the acceptable tolerance have been identified to have complex Heating, Ventilation, and Air Conditioning (HVAC) systems that the ideal loads air systems could not replicate. Because HVAC systems consume one of the largest proportions of energy in commercial buildings, this has a significant impact on the reliability of the template models. To address this issue, a set of detailed HVAC systems were needed to replace the ideal loads air systems. Due to HVAC system parameters not being collected by the BEES team and the lack of published modelling input parameters available, it is unknown what values are reasonable to use in the models. This study used a Delphi survey to collect real building information of the commonly installed HVAC systems in New Zealand commercial buildings. The survey formed a consensus between HVAC engineers that determined what the most commonly installed systems are and their associated performance values. The outcome of the survey was a documented set of system types and modelling input parameters that are representative of New Zealand HVAC systems. The responses of the survey were used to produce a set of HVAC system templates that replace the ideal loads air systems. The HVAC template models updated the software default parameter values with values that are representative of commonly installed systems in New Zealand. The importance of the updated input values was illustrated through a comparison of the calculated monthly energy consumption. The resulting difference in energy consumption using the updated parameter values is typically <5% monthly; at worst it is 75% for Variable Air Volume (VAV) system in the Wellington climate during June.</p>

scholarly journals Alternativa energética sustentable mediante la utilización de aislantes térmicos de diferentes materiales en edificaciones con sistemas de aire acondicionado

2020 ◽  
pp. 1-8
Author(s):  
Edzel Jair Casados-López ◽  
Alvaro Casados-Sánchez ◽  
Raúl Cruz-Vicencio ◽  
Alvaro Horst-Sánche
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Energy Savings ◽  
Cooling Load ◽  
Test Models ◽  
Scale Models ◽  
Conditioning Equipment ◽  
Actual Energy Consumption ◽  
Reduction Of Co2 ◽  
The City

A methodology is proposed for calculating the cooling load and the energy consumption of air conditioning equipment in three scale models of buildings under study, using the ASHRAE CLTD / SCL / CLF method. The building in which the mentioned method is used are three scale models of buildings located in the city of Poza Rica, state of Veracruz, Mexico. This method is applied in order to obtain the cooling load as exact as possible and thus avoid oversizing in air conditioning equipment, and by using thermal insulation, achieve a decrease in energy consumption and thus contribute to the reduction of CO2 emissions, to energy saving and therefore to sustainable development. The cooling load is calculated by applying the proposed methodology to three cases: model A, B and C. The results for the three test models, object of this study, are compared. Measurements of energy consumption are made to perform the error analysis of the actual energy consumption with respect to that calculated using the method. Finally, energy savings are quantified, in the cases mentioned.

Building Energy Simulation for LEED Qualification on a Commercial Building in China

2012 ◽  
Vol 193-194 ◽  
pp. 258-269 ◽  
Author(s):  
Ching Hin Law ◽  
Jian Kun Yang ◽  
Xiang Yang Jiang
Keyword(s):  
Energy Consumption ◽  
Energy Cost ◽  
Building Energy ◽  
Energy Performance ◽  
Energy Simulation ◽  
Building Energy Simulation ◽  
Commercial Building ◽  
Simulation Process

This research introduced and implemented building energy simulation via a case study of a commercial project in China, by considering the green features which can reduce the annual energy consumption of this building. This simulation process was based on the requirement described within LEED EA c1 Optimize Energy Performance. The result concluded that more than 39.41% of energy cost was reduced and thus the project can obtain 16 points from this credit.

scholarly journals Energy Performance Comparison between Liquid-Desiccant-Assisted Air Conditioning System and Dedicated Outdoor Air System in Different Climatic Regions

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1798
Author(s):  
Su Liu ◽  
Sang-Tae No ◽  
Jae-Weon Jeong
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Building Design ◽  
Energy Performance ◽  
Parallel System ◽  
Office Buildings ◽  
Outdoor Air ◽  
Liquid Desiccant ◽  
Climatic Regions ◽  
Air System

The main purpose of this research is to analyze and compare the energy performance of two different novel air conditioning systems; one is a dedicated outdoor air system (DOAS) with a parallel system and the other is a heat-pump-integrated liquid-desiccant and evaporative-cooling-assisted 100% outdoor air system (HPLD-IDECOAS). It was assumed that office buildings served by each system were located in six cities representing four different climatic regions in China. The hourly thermal loads of the office buildings meeting the local building design codes of each selected city were predicted by the TRNSYS 18 software package. The hourly thermal load data were imported into the commercial engineering equation solver (EES) program to estimate the operating energy consumption of each system via detailed energy simulations performed using valid system simulation models. The results show that the HPLD-IDECOAS has higher energy-saving potential than the DOAS with a parallel system in climate regions with high humidity, whereas, in dry regions, the difference in energy consumption between the two systems was not significant.

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.

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