The Experts below are selected from a list of 20511 Experts worldwide ranked by ideXlab platform

Juha Jokisalo - One of the best experts on this subject based on the ideXlab platform.

  • effects of night ventilation on indoor air quality in Educational Buildings a field study
    WOS, 2021
    Co-Authors: Sami Lestinen, Risto Kosonen, Juha Jokisalo, Simo Kilpelainen, Maria Valkonen, Pertti Pasanen
    Abstract:

    Night ventilation methods have been used in Educational Buildings to guarantee indoor air quality at the beginning of occupied periods. A typical method has been to pre-start ventilation 2 h before the space usage. Another selection has been to ventilate a building continuously during the night with a minimum airflow rate that can dilute material emissions. In this study, the pre-started, continuous, and intermittent ventilation methods were compared by assessing indoor air quality in field measurements. The daytime ventilation was operating normally. The test periods lasted for 2 weeks. Indoor air quality was assessed by measuring the total volatile organic compounds and microbial concentrations using the quantitative polymerase chain reaction method. Additionally, the thermal conditions, carbon dioxide, and pressure differences over the building envelope were measured. The results show that the night ventilation strategy had negligible effects on microbial concentrations. In most cases, the indoor air microbial concentrations were only a few percent of those found outdoors. The averaged concentration of total volatile organic compounds was at the same level with all the night ventilation methods at the beginning of the occupied periods in the mornings. The concentrations reached a minimum level after 2-h ventilation. The concentrations of total volatile organic compounds were higher during the day than at night. This reveals that space usage had the largest effect on the total volatile organic compounds. Generally, the results show that continuous night ventilation does not significantly affect the biological and chemical contaminants. Consequently, a 2-h flushing period is long enough to freshen indoor air before occupancy.

  • cost optimal energy performance renovation measures of Educational Buildings in cold climate
    Applied Energy, 2016
    Co-Authors: Tuomo Niemelä, Risto Kosonen, Juha Jokisalo
    Abstract:

    Abstract The paper discusses cost-efficient energy performance renovation measures for typical Educational Buildings built in the 1960s and 1970s in cold climate regions. The study analyzes the impact of different energy renovation measures on the energy efficiency and economic viability in a Finnish case study Educational building located in Lappeenranta University of Technology (LUT) campus area. The main objective of the study was to determine the cost-optimal energy performance renovation measures to meet the proposed national nearly zero-energy building (nZEB) requirements, which are defined according to the primary energy consumption of Buildings. The main research method of the study was simulation-based optimization (SBO) analysis, which was used to determine the cost-optimal renovation solutions. The results of the study indicate that the minimum national energy performance requirement of new Educational Buildings (E primary  ⩽ 170 kWh/(m 2 ,a)) can be cost-effectively achieved in deep renovations of Educational Buildings. In addition, the proposed national nZEB-targets are also well achievable, while improving the indoor climate (thermal comfort and indoor air quality) conditions significantly at the same time. Cost-effective solutions included renovation of the original ventilation system, a ground source heat pump system with relatively small dimensioning power output, new energy efficient windows and a relatively large area of PV-panels for solar-based electricity production. The results and conclusions of this study can be generalized to similar climates and techno-economic environments.

  • economic viability of energy efficiency measures in Educational Buildings in finland
    Advances in Building Energy Research, 2013
    Co-Authors: Kari Alanne, Juha Jokisalo, Jutta Schade, Ivo Martinac, Arto Saari, Targo Kalamees
    Abstract:

    The economic viability of novel energy-efficient design concepts has been evaluated in Finnish Educational Buildings. The total energy consumption of representative target Buildings with each desig ...

Alessandro Franco - One of the best experts on this subject based on the ideXlab platform.

  • multi objective optimization of hvac operation for balancing energy use and occupant comfort in Educational Buildings
    Energies, 2021
    Co-Authors: Alessandro Franco, Carlo Bartoli, Paolo Conti, Lorenzo Miserocchi, Daniele Testi
    Abstract:

    The paper provides a methodology for the optimal control of heating, ventilation, and air conditioning (HVAC) systems used in public Buildings, with the purpose of obtaining high comfort and safety standards along with energy efficiency. The combination of the two concurrent objectives of minimizing energy use and guaranteeing high standards of occupant comfort is obtained by means of multi-objective optimization, in which a comfort model is combined along with a dynamic energy model of the building. The use of dynamic setpoints for the HVAC and the inclusion of comfort indicators represent a step forward, compared to the current design and operation procedures suggested by technical standards. The utilization of the proposed methodology is tested with reference to a case study, represented by an academic building used by the University of Pisa for Educational purposes, whose extensive and variable occupancy can help to emphasize the importance of comfort in the operation of HVAC systems in different climatic conditions and with different occupancy profiles. We show how this optimization brings interesting results in terms of energy-saving (up to 30%), obtaining an increased comfort level (of more than 25%) compared to the operating conditions suggested by technical standards.

  • measurement of co2 concentration for occupancy estimation in Educational Buildings with energy efficiency purposes
    Journal of building engineering, 2020
    Co-Authors: Alessandro Franco, Francesco Leccese
    Abstract:

    Abstract The measurement of CO2 concentration is a relevant indicator for defining the occupation of indoor spaces. The real-time knowledge of occupation of such spaces is relevant both for maintaining indoor air quality standards and for energy efficiency purposes connected with the operation of heating, ventilation, and air-conditioning (HVAC) systems. The exact knowledge of occupation allows for rapid feedback from and the regulation of an HVAC system and the ventilation rate. Interesting applications include Educational Buildings and other Buildings of the civil sector (e.g., shopping centres and hospitals). This paper provides the results of an experimental analysis in different classrooms of a university campus under real operating conditions, in different periods of the year, and with different kinds of activities. The correlation between the CO2 concentration and occupancy profiles of the spaces is then analysed. Some graphical trends of the CO2 concentrations in these indoor spaces are provided to determine the most important variables affecting such concentrations. The basic elements of the mathematical models for estimating the occupation of classrooms in relation to increases in CO2 concentration are also discussed and analysed.

Faris Abdullah Almaziad - One of the best experts on this subject based on the ideXlab platform.

  • techno economic assessment of energy retrofitting Educational Buildings a case study in saudi arabia
    Sustainability, 2020
    Co-Authors: Mohammad B Hamida, Wahhaj Ahmed, Muhammad Asif, Faris Abdullah Almaziad
    Abstract:

    The Buildings and construction sector accounts for the majority of the energy consumption in the Kingdom of Saudi Arabia (KSA). For a sustainable future, energy consumption in the sector should be reduced and existing Buildings need to be energy retrofitted. A number of studies present energy retrofitting of residential Buildings in KSA; however, there is a lack of studies presenting retrofitting of Educational Buildings. Thus, the aim of this study is to adopt a BIM-based approach to assess Energy Conservation Measures (ECMs) in a prototypical Government-built Educational building in Dammam, KSA. The methodology consists of six prime steps, (1) case study data collection, (2) energy auditing, (3) proposing ECMs, (4) BIM model development, (5) energy assessment, and (6) economic assessment. The energy audit revealed several inefficiencies in the building construction and operation and four ECMs were proposed and simulated. It was found that annual energy consumption can be reduced by 22.7% in the Educational building, and the investment for the four ECMs is paid back in 2.7 years only. Therefore, implementing the proposed ECMs is a viable option to energy retrofit such Educational Buildings in the country, and the presented BIM-based approach can be adopted to efficiently conduct the energy retrofitting process.

Francesco Leccese - One of the best experts on this subject based on the ideXlab platform.

  • advancement on thermal comfort in Educational Buildings current issues and way forward
    Sustainability, 2021
    Co-Authors: Giulia Lamberti, Fabio Fantozzi, Giacomo Salvadori, Francesco Leccese, Philomena M Bluyssen
    Abstract:

    The thermal environment in Educational Buildings is crucial to improve students’ health and productivity, as they spend a considerable amount of time in classrooms. Due to the complexity of Educational Buildings, research performed has been heterogeneous and standards for thermal comfort are based on office studies with adults. Moreover, they rely on single dose-response models that do not account for interactions with other environmental factors, or students’ individual preferences and needs. A literature study was performed on thermal comfort in Educational Buildings comprising of 143 field studies, to identify all possible confounding parameters involved in thermal perception. Educational stage, climate zone, model adopted to investigate comfort, and operation mode were then selected as confounding parameters and discussed to delineate the priorities for future research. Results showed that children often present with different thermal sensations than adults, which should be considered in the design of energy-efficient and comfortable Educational environments. Furthermore, the use of different models to analyse comfort can influence field studies’ outcomes and should be carefully investigated. It is concluded that future studies should focus on a more rational evaluation of thermal comfort, also considering the effect that local discomfort can have on the perception of an environment. Moreover, it is important to carefully assess possible relationships between HVAC systems, building envelope, and thermal comfort, including their effect on energy consumption. Since several studies showed that the perception of the environment does not concern thermal comfort only, but it involves the aspects of indoor air, acoustic, and visual quality, their effect on the health and performance of the students should be assessed. This paper provides a way forward for researchers, which should aim to have an integrated approach through considering the positive effects of indoor exposure while considering possible individual differences.

  • measurement of co2 concentration for occupancy estimation in Educational Buildings with energy efficiency purposes
    Journal of building engineering, 2020
    Co-Authors: Alessandro Franco, Francesco Leccese
    Abstract:

    Abstract The measurement of CO2 concentration is a relevant indicator for defining the occupation of indoor spaces. The real-time knowledge of occupation of such spaces is relevant both for maintaining indoor air quality standards and for energy efficiency purposes connected with the operation of heating, ventilation, and air-conditioning (HVAC) systems. The exact knowledge of occupation allows for rapid feedback from and the regulation of an HVAC system and the ventilation rate. Interesting applications include Educational Buildings and other Buildings of the civil sector (e.g., shopping centres and hospitals). This paper provides the results of an experimental analysis in different classrooms of a university campus under real operating conditions, in different periods of the year, and with different kinds of activities. The correlation between the CO2 concentration and occupancy profiles of the spaces is then analysed. Some graphical trends of the CO2 concentrations in these indoor spaces are provided to determine the most important variables affecting such concentrations. The basic elements of the mathematical models for estimating the occupation of classrooms in relation to increases in CO2 concentration are also discussed and analysed.

Jiayu Chen - One of the best experts on this subject based on the ideXlab platform.

  • assessing occupants energy load variation through existing wireless network infrastructure in commercial and Educational Buildings
    Energy and Buildings, 2014
    Co-Authors: Jiayu Chen
    Abstract:

    Abstract Providing energy-consumption feedback has proven to be an effective approach for changing people's behavior and has led to significant energy-consumption reductions in residential Buildings. However, providing feedback in commercial and Educational Buildings is challenging because of the difficulty in tracking occupants’ behaviors and their corresponding energy usage – especially for temporary occupants. To make providing such feedback possible in commercial and Educational Buildings, this paper presents the framework for a coupled system that uses residents’ wireless devices’ Wi-Fi connection and disconnection events to detect occupancy and then benchmarks energy loads against these events to monitor the energy use of occupants. A preliminary experiment implemented the proposed approach in a small-scale Educational building to ascertain whether Wi-Fi network connection/disconnection events can be an effective indicator of energy load variation. The experiment's results confirmed the positive relationship between the Wi-Fi connection events and energy load increase; these results also indicated that the number of Wi-Fi connections cannot directly represent the magnitude of the energy load. A validation test was also conducted to assess the robustness of the coupled system in terms of the impact of users’ schedules (AM/PM), their length of stay (long-term/temporary), and the locations of access points.

  • assessing occupants energy load variation in commercial and Educational Buildings occupancy detecting approach based on existing wireless network infrastructure
    2014 Construction Research Congress: Construction in a Global Network CRC 2014, 2014
    Co-Authors: Jiayu Chen, Changbum R Ahn
    Abstract:

    Providing energy-consumption feedback has the potential to change people’s behavior, a reality that has led to significant energy-usage reductions in residential Buildings. However, it is challenging to provide feedback in commercial and Educational Buildings because it is difficult to track occupants’ behaviors and their corresponding energy usage—especially for temporary occupants. In order to make providing such feedback possible in commercial and Educational Buildings, this paper presents a coupled system that monitors the energy load for occupants who have WiFi-enabled devices. The system benchmarks energy loads using an energy monitoring system that simultaneously detects occupancy and roughly estimates the residents’ location through Wi-Fi access points. A preliminary experiment was conducted in an Educational building to illustrate the data processing procedure and to test the validity of the system. The experiment results suggest the event of wireless connection is a valid indication of energy load variation. The proposed system is the prototype of a coupled system that, in the future, will be able to estimate individual’s energy load through an indoor positioning system and, in turn, provide corresponding energyconsumption feedback.