scholarly journals Energy Efficiency – Indoor Air Quality Dilemma in Educational Buildings

2020 ◽  
Author(s):  
◽  
Līva Asere
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Air Quality ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Gas Emissions ◽  
Educational Buildings ◽  
Ventilation Systems

The largest energy consumer in Europe is the building sector, which uses about 40 % of total energy consumption and generates around 36 % of total CO2 emissions in the EU [1], [2]. Rising trends in energy consumption can be observed globally due to the demand of citizens for increased comfort, wider use of electrical equipment as well as other reasons. As energy consumption increases, climate change is promoted. In a number of areas energy could be used more efficiently, minimizing its consumption and, thus, resulting in a reduction of greenhouse gas emissions. To achieve carbon neutrality in 2050 in Europe Union, ambitious targets have been set, such as improving energy efficiency by 41 %, using 100 % of renewable energy sources and reducing greenhouse gas emissions of 80 % to 100 % [1], [3], [4]. Energy efficient buildings help to reduce heat consumption. State and local authorities need to set an example by improving the energy efficiency of their own buildings in order to encourage changes in other buildings as well. Moreover, the introduction of energy efficiency measures in buildings owned by the public sector contributes to the objectives of national climate policy. However, increasing energy efficiency has resulted in buildings becoming more airtight and natural ventilation systems need to be replaced by mechanical ventilation. However, this, in turn, leads to additional energy consumption costs. To avoid cost increases, building managers do not operate or operate unsatisfactory ventilation systems creating unfavourable indoor air quality. This creates a dilemma of energy efficiency and indoor air quality, which reduces performance of building occupants. This dilemma reduces pupils’ performance in educational buildings, reducing their chances of obtaining a good education and in the future working with higher added value which in turn reduces the country’s gross domestic product. The objective of the Thesis is to perform an assessment on energy efficiency – indoor air quality dilemma in educational buildings, its impact analyses on national prosperity, and to propose a solution to the prevention of the dilemma. The Thesis is based on six thematic joint scientific publications. The thesis consists of an introduction and three chapters. Four hypotheses have been formulated in the work that are further studied by various research methods, including system dynamic modelling, measurements in real sites and cost-benefit analysis. The thesis begins with an introduction continuing with a literature review of the topics. Chapter 2 presents the study methods. Chapter 3 examines the results obtained during the study and at the end of the Thesis, the findings are summarised according to the hypotheses.

scholarly journals Energy Efficiency – Indoor Air Quality Dilemma in Educational Buildings: A Possible Solution

2020 ◽  
Vol 24 (1) ◽  
pp. 357-367
Author(s):  
Liva Asere ◽  
Andra Blumberga
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Pv System ◽  
Educational Buildings ◽  
Electricity Tariff

AbstractThe energy efficiency – indoor air quality dilemma is well known and the main drawback to operate the mechanical ventilation is electricity costs as concluded from previous studies. Educational buildings are one of the places where future taxpayers spend a lot of time. This paper aims to study an alternative solution on how to reduce energy efficiency – indoor air quality dilemma in educational buildings by adopting systems that use renewable energy sources. A typical education building in Latvia is taken as a case study by changing it from a consumer to prosumer. This building type has a specific electricity usage profile that makes the choice of photovoltaics (PV) power quite challenging so the various power options have been analysed and used for an electricity solution. Also, the more decentralised preference is chosen – disconnect from a public heating provider and using a local system with a pellet boiler. Educational buildings using PV can reduce the electricity tariff, but the payback periods are still not very satisfactory without subsidies. The average electricity tariff per month varies between scenarios and the best one is for the scenario with 30 kW installed power. The educational building partly using 16 kW PV system reduces not only its bill for electricity but also reduces CO2 emissions by around 36 tons. The education buildings as energy prosumers using renewable energy sources are reducing GHG emissions by having high indoor air quality.

scholarly journals The Applicability of Coanda Effect Hysteresis for Designing Unsteady Ventilation Systems

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Aldona Skotnicka-Siepsiak
Keyword(s):  
Mechanical Ventilation ◽  
Energy Efficiency ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Residential Buildings ◽  
Coanda Effect ◽  
Air Jet ◽  
Coandǎ Effect ◽  
Ventilation Systems

Energy-saving ventilation systems are designed to improve the energy efficiency of buildings. Low energy efficiency in buildings poses a considerable problem that needs to be addressed. Mechanical ventilation with heat recovery has gained increased popularity in recent years. Mechanical ventilation has numerous advantages, including easy adjustment and control, high indoor air quality and elimination of indoor pollutants. Mixing ventilation is the most popular type of mechanical ventilation, in particular in residential buildings. Unsteady ventilation is a type of mixing ventilation that involves stronger mixing effects and smaller vertical temperature gradients to improve indoor air quality (IAQ) and minimize energy consumption. This study examines the possibility of controlling and modifying Coanda effect hysteresis (CEH) to generate unsteady flow and simulate the conditions of unsteady mixing ventilation. The experiment was performed on a self-designed test bench at the University of Warmia and Mazury in Olsztyn. It demonstrated that an auxiliary nozzle can be applied at the diffuser outlet to control CEH and the angles at which the air jet becomes attached to and separated from the flat plate positioned directly behind the nozzle. The study proposes an innovative mixing ventilation system that relies on CEH. The potential of the discussed concept has not been recognized or deployed in practice to date. This is the first study to confirm that an auxiliary nozzle by the diffuser outlet can be operated in both injection and suction mode to control CEH. In the future, the results can be used to design a new type of nozzles for unsteady ventilation systems that are based on CEH control.

scholarly journals Research on Best Solution for Improving Indoor Air Quality and Reducing Energy Consumption in a High-Risk Radon Dwelling from Romania

2021 ◽  
Vol 18 (23) ◽  
pp. 12482
Author(s):  
Ion-Costinel Mareș ◽  
Tiberiu Catalina ◽  
Marian-Andrei Istrate ◽  
Alexandra Cucoș ◽  
Tiberius Dicu ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Heat Recovery ◽  
Natural Ventilation ◽  
High Efficiency ◽  
Ventilation System ◽  
Radon Level

The purpose of this article is the assessment of energy efficiency and indoor air quality for a single-family house located in Cluj-Napoca County, Romania. The studied house is meant to be an energy-efficient building with thermal insulation, low U-value windows, and a high efficiency boiler. Increasing the energy efficiency of the house leads to lower indoor air quality, due to lack of natural ventilation. As the experimental campaign regarding indoor air quality revealed, there is a need to find a balance between energy consumption and the quality of the indoor air. To achieve superior indoor air quality, the proposed mitigation systems (decentralized mechanical ventilation with heat recovery combined with a minimally invasive active sub-slab depressurization) have been installed to reduce the high radon level in the dwelling, achieving an energy reduction loss of up to 86%, compared to the traditional natural ventilation of the house. The sub-slab depressurization system was installed in the room with the highest radon level, while the local ventilation system with heat recovery has been installed in the exterior walls of the house. The results have shown significant improvement in the level of radon decreasing the average concentration from 425 to 70 Bq/m 3, respectively the carbon dioxide average of the measurements being around 760 ppm. The thermal comfort improves significantly also, by stabilizing the indoor temperature at 21 °C, without any important fluctuations. The installation of this system has led to higher indoor air quality, with low energy costs and significant energy savings compared to conventional ventilation (by opening windows).

scholarly journals Interaction between Thermal Comfort, Indoor Air Quality and Ventilation Energy Consumption of Educational Buildings: A Comprehensive Review

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 591
Author(s):  
Lin-Rui Jia ◽  
Jie Han ◽  
Xi Chen ◽  
Qing-Yun Li ◽  
Chi-Chung Lee ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Well Being ◽  
Design Parameters ◽  
Considerable Proportion ◽  
Comprehensive Review ◽  
Educational Buildings

Thermal comfort and indoor air quality (IAQ) of educational buildings can affect students’ academic performance and well-being and are closely related to ventilation energy consumption. Demands of the indoor environmental quality within the classroom generally vary with the education levels and result in ventilation energy consumption accounting for a considerable proportion of the total energy use in bulk educational buildings. Its huge energy-saving potential is attracting worldwide attention from scholars and governments. Therefore, appropriate operation strategies of ventilation systems should be adopted to effectively reduce energy consumption without sacrificing thermal comfort and IAQ. However, the absence of relevant standards and guidelines for designing a quality classroom environment considering the special features of educational buildings remains an important research question. This study conducts a comprehensive review to determine research gaps and identify future directions for the interaction between thermal comfort, IAQ and ventilation energy consumption for educational buildings. The review results show that: (1) The thermal comfort prediction model should consider the influences of genders, ages and socioeconomic backgrounds; (2) The mixed-mode ventilation coupling the natural and mechanical approaches is preferred given its advantage of lower energy consumption and improved thermal comfort, but its control strategies need further exploration; (3) Optimizing passive design parameters of buildings (e.g., window to wall ratios, window orientations and sun shading installations) can significantly reduce the ventilation demands while maintaining indoor thermal comfort; (4) More studies are required for investigating thermal comfort in educational buildings during the heating period; and (5) IAQ of university buildings clearly requires further studies, especially on bacterial and fungal aerosol pollutants, for a more comprehensive assessment of the built environment.

Analysing Nexus between Economic Growth, GHG Emissions, and Energy Consumption for India

2021 ◽  
Vol 17 (1) ◽  
pp. 1-16
Author(s):  
Asim Hasan ◽  
Rahil Akhtar Usmani
Keyword(s):  
Economic Growth ◽  
Energy Consumption ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Carbon Emissions ◽  
Series Data ◽  
Gas Emissions ◽  
Current Time ◽  
Causal Influence ◽  
Integration Test

Rising greenhouse gas emissions is an important issue of the current time. India’s massive greenhouse gas emissions is ranked third globally. The escalating energy demand in the country has opened the gateway for further increase in emissions. Recent studies suggest strong nexus between energy consumption, economic growth, and carbon emissions. This study has the objective to empirically test the aforementioned interdependencies. The co-integration test and multivariate vector error correction model (VECM) are used for the analysis and the Granger Causality test is used to establish the direction of causality. The time-series data for the period of 1971–2011 is used for the analysis. The results of the study confirm strong co-integration between variables. The causality results show that economic growth exerts a causal influence on carbon emissions, energy consumption exerts a causal influence on economic growth, and carbon emissions exert a causal influence on economic growth. Based on the results, the study suggests a policy that focuses on energy conservation and gradual replacement of fossil fuels with renewable energy sources, which would be beneficial for the environment and the society.

scholarly journals The Dichotomy between Indoor Air Quality and Energy Efficiency in Light of the Onset of the COVID-19 Pandemic

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 791
Author(s):  
Gaetano Settimo ◽  
Pasquale Avino
Keyword(s):  
Energy Efficiency ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Great Increase

Recently, there has been a great increase in the importance of issues related to energy efficiency [...]

scholarly journals Impact of Cycle Time and Payload of an Industrial Robot on Resource Efficiency

Robotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 33
Author(s):  
Florian Stuhlenmiller ◽  
Steffi Weyand ◽  
Jens Jungblut ◽  
Liselotte Schebek ◽  
Debora Clever ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Energy Consumption ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Resource Efficiency ◽  
Life Cycle Costs ◽  
Gas Emissions ◽  
Cycle Times ◽  
The Individual

Modern industry benefits from the automation capabilities and flexibility of robots. Consequently, the performance depends on the individual task, robot and trajectory, while application periods of several years lead to a significant impact of the use phase on the resource efficiency. In this work, simulation models predicting a robot’s energy consumption are extended by an estimation of the reliability, enabling the consideration of maintenance to enhance the assessment of the application’s life cycle costs. Furthermore, a life cycle assessment yields the greenhouse gas emissions for the individual application. Potential benefits of the combination of motion simulation and cost analysis are highlighted by the application to an exemplary system. For the selected application, the consumed energy has a distinct impact on greenhouse gas emissions, while acquisition costs govern life cycle costs. Low cycle times result in reduced costs per workpiece, however, for short cycle times and higher payloads, the probability of required spare parts distinctly increases for two critical robotic joints. Hence, the analysis of energy consumption and reliability, in combination with maintenance, life cycle costing and life cycle assessment, can provide additional information to improve the resource efficiency.

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