scholarly journals Energy Conservation Potential of Economizer Controls Using Optimal Outdoor Air Fraction Based on Field Study

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5038
Author(s):  
Goopyo Hong ◽  
Chul Kim ◽  
Jun Hong
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Temperature Control ◽  
Energy Savings ◽  
Cooling System ◽  
Energy Performance ◽  
Outdoor Air ◽  
Humid Climate ◽  
Differential Enthalpy ◽  
The Impact

In commercial buildings, HVAC systems are becoming a primary driver of energy consumption, which already account for 45% of the total building energy consumption. In the previous literature, researchers have studied several energy conservation measures to reduce HVAC system energy consumption. One of the effective ways is an economizer in air-handling units. Therefore, this study quantified the impact of the outdoor air fraction by economizer control type in cooling system loads based on actual air-handling unit operation data in a hospital. The optimal outdoor air fraction and energy performance for economizer control types were calculated and analyzed. The result showed that economizer controls using optimal outdoor air fraction were up to 45% more efficient in cooling loads than existing HVAC operations in the hospital. The energy savings potential was 6–14% of the differential dry-bulb temperature control, 17–27% of the differential enthalpy control, 8–17% of the differential dry-bulb temperature and high-limit differential enthalpy control, and 16–27% of the differential enthalpy and high-limit differential dry-bulb temperature control compared to the no economizer control. The result of this study will contribute to providing a better understanding of economizer controls in the hospital when the building operates in hot-humid climate regions.

Impact of roof shading on building energy performance in warm & humid climatic places of India

2020 ◽  
pp. 50-64
Author(s):  
Kuladeep Kumar Sadevi ◽  
Avlokita Agrawal
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Energy Performance ◽  
General Assumption ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Passive Cooling ◽  
Base Case ◽  
U Value ◽  
The Impact

With the rise in awareness of energy efficient buildings and adoption of mandatory energy conservation codes across the globe, significant change is being observed in the way the buildings are designed. With the launch of Energy Conservation Building Code (ECBC) in India, climate responsive designs and passive cooling techniques are being explored increasingly in building designs. Of all the building envelope components, roof surface has been identified as the most significant with respect to the heat gain due to the incident solar radiation on buildings, especially in tropical climatic conditions. Since ECBC specifies stringent U-Values for roof assembly, use of insulating materials is becoming popular. Along with insulation, the shading of the roof is also observed to be an important strategy for improving thermal performance of the building, especially in Warm and humid climatic conditions. This study intends to assess the impact of roof shading on building’s energy performance in comparison to that of exposed roof with insulation. A typical office building with specific geometry and schedules has been identified as base case model for this study. This building is simulated using energy modelling software ‘Design Builder’ with base case parameters as prescribed in ECBC. Further, the same building has been simulated parametrically adjusting the amount of roof insulation and roof shading simultaneously. The overall energy consumption and the envelope performance of the top floor are extracted for analysis. The results indicate that the roof shading is an effective passive cooling strategy for both naturally ventilated and air conditioned buildings in Warm and humid climates of India. It is also observed that a fully shaded roof outperforms the insulated roof as per ECBC prescription. Provision of shading over roof reduces the annual energy consumption of building in case of both insulated and uninsulated roofs. However, the impact is higher for uninsulated roofs (U-Value of 3.933 W/m2K), being 4.18% as compared to 0.59% for insulated roofs (U-Value of 0.33 W/m2K).While the general assumption is that roof insulation helps in reducing the energy consumption in tropical buildings, it is observed to be the other way when insulation is provided with roof shading. It is due to restricted heat loss during night.

Assessment of Different Natural Ventilation Strategies for an Educational Building on the Warm-Humid Climate of Guayaquil, Ecuador

2015 ◽  
Author(s):  
R. David Beltrán ◽  
Juan Kastillo ◽  
Isabel Miño-Rodríguez ◽  
Carlos Naranjo-Mendoza ◽  
Carlos Ávila
Keyword(s):  
Energy Consumption ◽  
Natural Ventilation ◽  
Energy Savings ◽  
Main Concern ◽  
Humid Climate ◽  
The Real ◽  
Ventilation Strategies ◽  
Definition Of ◽  
The Impact ◽  
Real State

Natural ventilation has been studied as an effective strategy in order to reduce energy consumption without compromising occupant’s hygrothermal comfort in warm-humid climates. However, the main concern about the current state of art in the use of Building Energy Simulation (BES) as an approach to natural ventilation is the definition of input data which usually do not represent the real state of the buildings in the studied region. Within this context, the main contribution of this research is to propose a methodology through which the real state of buildings can be evaluated. By this analysis, valid input parameters was found to exploit the capabilities of BES and CFD simulations to fulfill the main objective of this study, which is to assess the impact of natural ventilation strategies in the energy consumption of HVAC systems and occupants hygrothermal comfort. Four natural ventilation strategies were evaluated: single sided ventilation, cross ventilation, solar chimney and double façade. The results show that the exclusive use of natural ventilation is ineffective to ensure hygrothermal comfort in a building with high thermal loads in a warm-humid climate like Guayaquil. However, by using a hybrid system (natural ventilation/dehumidification and cooling) cooling energy consumption can be reduced in up to 10.6% without compromising occupant’s hygrothermal comfort. Due to the promising results regarding energy savings, further research will aim to evaluate the impact of other passive strategies in energy consumption.

scholarly journals Impact of the COVID-19 Pandemic on the Energy Use at the University of Almeria (Spain)

2021 ◽  
Vol 13 (11) ◽  
pp. 5843
Author(s):  
Mehdi Chihib ◽  
Esther Salmerón-Manzano ◽  
Mimoun Chourak ◽  
Alberto-Jesus Perea-Moreno ◽  
Francisco Manzano-Agugliaro
Keyword(s):  
Energy Consumption ◽  
Energy Use ◽  
Energy Savings ◽  
Electricity Consumption ◽  
Energy Performance ◽  
Energy Sector ◽  
Wide Range ◽  
University Buildings ◽  
The University ◽  
The Impact

The COVID-19 pandemic has caused chaos in many sectors and industries. In the energy sector, the demand has fallen drastically during the first quarter of 2020. The University of Almeria campus also declined the energy consumption in 2020, and through this study, we aimed to measure the impact of closing the campus on the energy use of its different facilities. We built our analysis based upon the dataset collected during the year 2020 and previous years; the patterns evolution through time allowed us to better understand the energy performance of each facility during this exceptional year. We rearranged the university buildings into categories, and all the categories reduced their electricity consumption share in comparison with the previous year of 2019. Furthermore, the portfolio of categories presented a wide range of ratios that varied from 56% to 98%, the library category was found to be the most influenced, and the research category was found to be the least influenced. This opened questions like why some facilities were influenced more than others? What can we do to reduce the energy use even more when the facilities are closed? The university buildings presented diverse structures that revealed differences in energy performance, which explained why the impact of such an event (COVID-19 pandemic) is not necessarily relevant to have equivalent variations. Nevertheless, some management deficiencies were detected, and some energy savings measures were proposed to achieve a minimum waste of energy.

scholarly journals Industrial Decarbonization by a New Energy-Baseline Methodology. Case Study

2020 ◽  
Vol 12 (5) ◽  
pp. 1960
Author(s):  
Rosaura Castrillón-Mendoza ◽  
Javier M. Rey-Hernández ◽  
Francisco J. Rey-Martínez
Keyword(s):  
Energy Consumption ◽  
Energy Management ◽  
Energy Efficient ◽  
Energy Savings ◽  
Energy Performance ◽  
High Energy ◽  
Industrial Sector ◽  
Raw Material ◽  
Management Plans ◽  
The Impact

The main target of climate change policies in the majority of industrialized countries is to reduce energy consumption in their facilities, which would reduce the carbon emissions that are generated. Through this idea, energy management plans are developed, energy reduction targets are established, and energy-efficient technologies are applied to achieve high energy savings, which are environmentally compatible. In order to evaluate the impact of their operations and investments, companies promote measures of performance in their energy management plans. An integral part of measuring energy performance is the establishment of energy baselines applicable to the complete facility that provide a basis for evaluating energy efficiency improvements and incorporating energy performance indicators. The implementation of energy management systems in accordance with the requirements of ISO Standard 50001 is a contribution to the aim and strategies for improving cleaner production in industries. This involves an option for the industry to establish energy benchmarks to evaluate performance, predict energy consumption, and align production with the lowest possible consumption of primary and secondary forms of energy. Ultimately, this goal should lead to the manufacturing of cleaner products that are environmentally friendly, energy efficient, and are in accordance with the global environmental targets of cleaner manufacturing. This paper discusses an alternative for establishing energy baselines for the industrial sector in which several products are produced from a single raw material, and we determined the energy consumption of each product and its impact on the overall efficiency of the industry at the same time. The method is applied to the plastic injection process and the result is an energy baseline (EBL) in accordance with the requirements of ISO 50001, which serves as a reference for determining energy savings. The EBL facilitates a reduction in energy consumption and greenhouse gas emissions in sectors such as plastics, a sector which accounts for 15% of Colombia’s manufacturing GDP.

scholarly journals Improving Building Energy Performance Using Dual VAV Configuration Integrated with Dedicated Outdoor Air System

Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 466
Author(s):  
Nabil Nassif ◽  
Iffat Ridwana
Keyword(s):  
Energy Consumption ◽  
Air Temperature ◽  
Energy Savings ◽  
Energy Performance ◽  
Office Building ◽  
Effective Control ◽  
Cooling Load ◽  
Outdoor Air ◽  
System A ◽  
Cooling Loads

As building systems account for almost half of the total energy consumed by the building sector to provide space heating, cooling, and ventilation, efficiently designing these systems can be the key to energy conservation in buildings. Dual VAV systems with an effective control strategy can substantially reduce the energy consumption in buildings, providing a significant scope of further research on this system configuration. This paper proposes to utilize the warm air duct of the dual VAV system as a dedicated outdoor air (DOA) unit when no heating is required, which allows the cooling load to be effectively distributed between two ducts. A specific control sequence is proposed with different supply air temperature reset strategies to estimate the heating, cooling loads, and fan power energy consumption of the proposed system. A simple two-zone office building is taken as a preliminary case study to simulate the airflow rates and fan power of a single duct VAV and proposed dual VAV systems to illustrate the concept. Finally, a larger multi-zone office building is simulated to measure the annual heating, cooling loads, and fan power energy and compare the energy savings among the systems. The results show significant fan power reduction ranging from 1.7 to 9% and notable heating energy reduction up to 76.5% with a small amount of cooling load reduction varying from 0.76 to 2.56% depending on the different locations for the proposed dual VAV systems. Further energy savings from different supply air temperature reset strategies demonstrate the opportunity of employing them according to climates and case studies. The proposed dual VAV system proves to have the potential to be adapted in buildings for the purpose of sustainability and energy savings.

Evaluation of Air-Side Economizer Use in a Compute-Intensive Data Center

2009 ◽  
Author(s):  
Michael K. Patterson ◽  
Don Atwood ◽  
John G. Miner
Keyword(s):  
New Mexico ◽  
Temperature Control ◽  
Environmental Conditions ◽  
Data Center ◽  
Energy Savings ◽  
Cooling System ◽  
Lessons Learned ◽  
Information And Communications Technology ◽  
The Impact

Moore’s Law continues to drive increased compute capability and greater performance per watt in today’s and future server platforms. However the increased demand for compute services has outstripped these gains and the energy consumption in the data center continues to rise. The challenge for the data center operator is to limit the operational costs and reduce the energy required to run the Information and Communications Technology (ICT) equipment and the supporting infrastructure. The cooling systems can represent a large portion of the energy use in the support infrastructure. There is significant focus in industry today on applying advanced cooling technologies to reduce this energy. One potential solution is the use of air-side economizers in the cooling system. This technology can provide a reduction in cooling energy by being able to maintain the required temperatures in the data center with the mechanical refrigeration turned off, significantly reducing the PUE for the data center. This paper reviews recent industry activities around the recommended environmental conditions in the data center, the impact to the ICT equipment of air-side economizers, where they can best be applied, and provides data from a case study recently concluded at Intel’s site in New Mexico. In that case study servers from an engineering compute data center were split into a standard configuration (closed system, tight temperature control) and a very aggressive air-side economization section (open system, significant out-door air quantities, moderate temperature control). Both sections performed equally well over a year long on-line test, with significant energy savings potential demonstrated by economizer side. The American Society of Air-conditioning Heating and Refrigerating Engineers (ASHRAE) has recently published new ICT-vendor consensus-based recommendations for the environmental conditions in data centers. These new limits are discussed in light of the successful experiment run in New Mexico as the revised operational envelop allows a far greater number of hours per year when a data center can be run in “free-cooling” mode to obtain the energy savings. Server design features as well as lessons learned from the experiment and their applicability to the potential use of air-side economizers is also discussed.

scholarly journals Energy Performance Assessment of Innovative Building Solutions Coming from Construction and Demolition Waste Materials

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1226
Author(s):  
Beatriz Fraga-De Cal ◽  
Antonio Garrido-Marijuan ◽  
Olaia Eguiarte ◽  
Beñat Arregi ◽  
Ander Romero-Amorrortu ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Energy Demand ◽  
Energy Savings ◽  
Flow Analysis ◽  
Weather Conditions ◽  
Energy Performance ◽  
Construction And Demolition Waste ◽  
The European Union ◽  
Demolition Waste ◽  
The Impact

Prefabricated solutions incorporating thermal insulation are increasingly adopted as an energy conservation measure for building renovation. The InnoWEE European project developed three technologies from Construction and Demolition Waste (CDW) materials through a manufacturing process that supports the circular economy strategy of the European Union. Two of them consisted of geopolymer panels incorporated into an External Thermal Insulation Composite System (ETICS) and a ventilated façade. This study evaluates their thermal performance by means of monitoring data from three pilot case studies in Greece, Italy, and Romania, and calibrated building simulation models enabling the reliable prediction of energy savings in different climates and use scenarios. Results showed a reduction in energy demand for all demo buildings, with annual energy savings up to 25% after placing the novel insulation solutions. However, savings are highly dependent on weather conditions since the panels affect cooling and heating loads differently. Finally, a parametric assessment is performed to assess the impact of insulation thickness through an energy performance prediction and a cash flow analysis.

scholarly journals A Fundamental Study on the Development of New Energy Performance Index in Office Buildings

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2064
Author(s):  
Jin-Hee Kim ◽  
Seong-Koo Son ◽  
Gyeong-Seok Choi ◽  
Young-Tag Kim ◽  
Sung-Bum Kim ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Requirement ◽  
Energy Performance ◽  
Office Buildings ◽  
Light Transmittance ◽  
Wall Structure ◽  
Fundamental Study ◽  
Future Studies ◽  
U Value ◽  
The Impact

Recently, there have been significant concerns regarding excessive energy use in office buildings with a large window-to-wall ratio (WWR) because of the curtain wall structure. However, prior research has confirmed that the impact of the window area on energy consumption varies depending on building size. A newly proposed window-to-floor ratio (WFR) correlates better with energy consumption in the building. In this paper, we derived the correlation by analyzing a simulation using EnergyPlus, and the results are as follows. In the case of small buildings, the results of this study showed that the WWR and energy requirement increase proportionally, and the smaller the size is, the higher the energy sensitivity will be. However, results also confirmed that this correlation was not established for buildings approximately 3600 m2 or larger. Nevertheless, from analyzing the correlation between the WFR and the energy requirements, it could be deduced that energy required increased proportionally when the WFR was 0.1 or higher. On the other hand, the correlation between WWR, U-value, solar heat gain coefficient (SHGC), and material property values of windows had little effect on energy when the WWR was 20%, and the highest effect was seen at a WWR of 100%. Further, with an SHGC below 0.3, the energy requirement decreased with an increasing WWR, regardless of U-value. In addition, we confirmed the need for in-depth research on the impact of the windows’ U-value, SHGC, and WWR, and this will be verified through future studies. In future studies on window performance, U-value, SHGC, visible light transmittance (VLT), wall U-value as sensitivity variables, and correlation between WFR and building size will be examined.

People or Systems: Does Productivity Enhancement Matter More than Energy Management in LEED Certified Buildings?

2021 ◽  
Vol 13 (24) ◽  
pp. 13863
Author(s):  
Yana Akhtyrska ◽  
Franz Fuerst
Keyword(s):  
Energy Consumption ◽  
Energy Management ◽  
Energy Use ◽  
Management Practices ◽  
Energy Savings ◽  
Occupant Comfort ◽  
Energy Use Intensity ◽  
Using Data ◽  
Advanced Metering ◽  
The Impact

This study examines the impact of energy management and productivity-enhancing measures, implemented as part of LEED Existing Buildings Operations and Management (EBOM) certification, on source energy use intensity and rental premiums of office spaces using data on four major US markets. Energy management practices, comprised of commissioning and advanced metering, may reduce energy usage. Conversely, improving air quality and occupant comfort in an effort to increase worker productivity may in turn lead to higher overall energy consumption. The willingness to pay for these features in rental office buildings is hypothesised to depend not only on the extent to which productivity gains enhance the profits of a commercial tenant but also on the lease arrangements for passing any energy savings to the tenant. We apply a difference-in-differences method at a LEED EBOM certification group level and a multi-level modelling approach with a panel data structure. The results indicate that energy management and indoor environment practices have the expected effect on energy consumption as described above. However, the magnitude of the achieved rental premiums appears to be independent of the lease type.

scholarly journals Determination of Optimum Envelope of Religious Buildings in Terms of Thermal Comfort and Energy Consumption: Mosque Cases

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6597
Author(s):  
Ahmet Bircan Atmaca ◽  
Gülay Zorer Gedik ◽  
Andreas Wagner
Keyword(s):  
Thermal Properties ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Thermal Insulation ◽  
Energy Savings ◽  
Gain Factor ◽  
Building Envelope ◽  
Comfort Level ◽  
Humid Climate ◽  
Savings Rate

Mosques are quite different from other building types in terms of occupant type and usage schedule. For this reason, they should be evaluated differently from other building types in terms of thermal comfort and energy consumption. It is difficult and probably not even necessary to create homogeneous thermal comfort in mosques’ entire usage area, which has large volumes and various areas for different activities. Nevertheless, energy consumption should be at a minimum level. In order to ensure that mosques are minimally affected by outdoor climatic changes, the improvement of the properties of the building envelope should have the highest priority. These optimal properties of the building envelope have to be in line with thermal comfort in mosques. The proposed method will be a guide for designers and occupants in the design process of new mosques or the use of existing mosques. The effect of the thermal properties of the building envelope on energy consumption was investigated to ensure optimum energy consumption together with an acceptable thermal comfort level. For this purpose, a parametric simulation study of the mosques was conducted by varying optical and thermal properties of the building envelope for a temperature humid climate zone. The simulation results were analyzed and evaluated according to current standards, and an appropriate envelope was determined. The results show that thermal insulation improvements in the roof dome of buildings with a large volume contributed more to energy savings than in walls and foundations. The use of double or triple glazing in transparent areas is an issue that should be considered together with the solar energy gain factor. Additionally, an increasing thickness of thermal insulation in the building envelope contributed positively to energy savings. However, the energy savings rate decreased after a certain thickness. The proposed building envelope achieved a 33% energy savings compared to the base scenario.

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