scholarly journals SIMULATION ON THERMAL COMFORT AND ENERGY CONSERVATION FOR DISPLACEMENT VENTILATION IN A RESIDENTIAL ROOM : Effect of air change rate and positoin of air inlet/outlet

2003 ◽  
Vol 68 (565) ◽  
pp. 83-90
Author(s):  
Lei XU ◽  
Weijun GAO ◽  
Toshio OJIMA
Keyword(s):  
Energy Conservation ◽  
Thermal Comfort ◽  
Displacement Ventilation ◽  
Change Rate ◽  
Air Inlet ◽  
Air Change Rate

New concepts for the ventilation of shopping centers: Reducing air change rate, applying active chilled beams and elevating cold water supply temperature

2017 ◽  
Vol 26 (2) ◽  
pp. 208-225 ◽  
Author(s):  
Paul Mathis ◽  
Henning Freitag ◽  
Daniela Hegemann ◽  
Martin Schmidt ◽  
Dirk Müller
Keyword(s):  
Air Quality ◽  
Water Supply ◽  
Thermal Comfort ◽  
Cold Water ◽  
Experimental Studies ◽  
Heat Removal ◽  
Primary Energy ◽  
Change Rate ◽  
New Concepts ◽  
Air Change Rate

New concepts of removing the cooling loads in shopping centres are presented in a multi-disciplinary study. In air-quality experiments, we found that the air change rate (ACR) in shops can be reduced significantly, while still maintaining acceptable air quality. Dilution curves of typical odour-intensive retail goods were measured, which show that ACRs can be reduced down to 1.75 h−1 without impacting odour perception significantly. Then, the standard ventilation systems were replaced by air–water systems, namely active chilled beams, which allow for a combined supply of fresh air and heat removal via the water circuit. To realize low ACRs in the shops, experimental studies for developing high-induction active chilled beam systems are presented. Finally, CFD simulations were conducted in a generic shop. Aspects like room air flow, odour propagation and thermal comfort were investigated. The cold water supply was assumed to be generated in a renewable way, leading to high cold water supply temperatures. Feasible ventilation configurations with ACRs as low as 1.1 h−1 have been identified without deteriorating either air quality or thermal comfort. Primary energy consumption was assessed according to German standards and was reduced by up to 67% with the presented approach.

The Impact of Gymnasium Form’s Tilting Side Interfaces on Natural Ventilation and Thermal Comfort of Exercise Site

2014 ◽  
Vol 587-589 ◽  
pp. 490-497
Author(s):  
Jin Li ◽  
Yuan You
Keyword(s):  
Thermal Comfort ◽  
Wind Velocity ◽  
Natural Ventilation ◽  
Change Rate ◽  
Symmetrical Mode ◽  
Air Change Rate ◽  
Window Opening ◽  
Symmetrical Model ◽  
Ventilation Strategies ◽  
The Impact

To improve air change rate and exercise site’s thermal comfort of gymnasium under natural ventilation in hot and humid areas, taking Guangzhou as an example, symmetrical model, unsymmetrical model, and unsymmetrical model with corbel table were simulated and calculated with Fluent and other software. The result indicates that, compared with symmetrical mode, unsymmetrical model and unsymmetrical model with corbel table can improve exercise site’s wind velocity and integral air change rate, and the latter model improves more. Based on unsymmetrical model with corbel table, window-opening ventilation strategies for competition are further put forward. In the end, it discusses about the influence towards thermal comfort of exercise site by natural ventilation in different form models and different use modes.

scholarly journals Influence of the Airflow in a Solar Passive Building on the Indoor Air Quality and Thermal Comfort Levels

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 766 ◽  
Author(s):  
Eusébio Conceição ◽  
João Gomes ◽  
Hazim Awbi
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Numerical Study ◽  
Change Rate ◽  
Comfort Levels ◽  
Air Change Rate ◽  
Typical Summer ◽  
Shading Devices

The influence of the airflow in a solar passive building on the indoor air quality and thermal comfort levels was investigated. The numerical study for a university library was conducted using a software that simulates the building thermal behavior with complex topology, in transient conditions, for evaluating the indoor air quality and occupants’ thermal comfort levels for typical summer and winter days. Solar radiation was used as a renewable energy source to increase simultaneously the thermal comfort and air quality levels and reduce building energy consumption. Regarding the solar passive building, consideration was given to all of the building structure envelope, shading devices and interior details, while in the solar active building active ventilation was used. To analyze the airflow that simultaneously provides the best indoor air quality and thermal comfort levels, a new integral methodology based on the minimization of the total number of uncomfortable hours was used. The results show that it was possible to determine an air change rate that ensures a good compromise between thermal comfort and indoor air quality. An optimal air change rate of two and three renewals per hour had been determined, respectively, for winter and summer conditions.

scholarly journals Building Retrofit and Energy Conservation/Efficiency Review: A Techno-Environ-Economic Assessment of Heat Pump System Retrofit in Housing Stock

2021 ◽  
Vol 13 (2) ◽  
pp. 983
Author(s):  
Mustapha Mukhtar ◽  
Bismark Ameyaw ◽  
Nasser Yimen ◽  
Quixin Zhang ◽  
Olusola Bamisile ◽  
...  
Keyword(s):  
Energy Conservation ◽  
Thermal Comfort ◽  
Heat Pump ◽  
Cooling System ◽  
Commercial Buildings ◽  
Optimization Techniques ◽  
Hot Water ◽  
Environmental Benefits ◽  
Pump System ◽  
Air Conditioners

The world has not been able to achieve minimum greenhouse gas emissions in buildings’ energy consumptions because the energy and emissions optimization techniques have not been fully utilized. Thermal comfort is one of the most important issues for both residential and commercial buildings. Out of the 40% of global energy consumed by buildings, a large fraction is used to maintain their thermal comfort. In this study, a comprehensive review of the recent advancements in building energy conservation and efficiency application is presented based on existing high-quality research papers. Additionally, the retrofit of the heating/cooling and hot water system for an entire community in Cyprus is presented. This study aims to analyze the technical and environmental benefits of replacing existing electric heaters for hot water with heat pump water heating systems and the use of heat pump air conditioners for thermal comfort in place of the existing ordinary air conditioners for space heating and cooling. One administrative building, 86 apartments (including residential and commercial) buildings, and a restaurant building is retrofitted, and the feasibility of the project is determined based on three economic indicators, namely; simple payback period (SPP), internal rate of return (IRR), and net present value (NPV). The electrical energy required by the hot water systems and the heating/cooling system is reduced by 263,564 kWh/yr and 144,825 kWh/yr, respectively. Additionally, the retrofit project will reduce Cyprus’ CO2 emission by 121,592.8 kg yearly. The SPP, IRR, and NPV for the project show that the retrofit is economically feasible.

scholarly journals Comparison of Downdraught and Up Draft Passive Air Conduction Systems (PACS) in a Winery Building

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 259
Author(s):  
Ádám László Katona ◽  
István Ervin Háber ◽  
István Kistelegdi
Keyword(s):  
Air Conditioning ◽  
Natural Ventilation ◽  
Dynamics Simulation ◽  
Computational Fluid Dynamics Simulation ◽  
General Applicability ◽  
Change Rate ◽  
Air Change Rate ◽  
Simulation Based ◽  
Ventilation Performance ◽  
Air Conduction

A huge portion of energy consumption in buildings comes from heating, ventilation, and air conditioning. Numerous previous works assessed the potential of natural ventilation compared to mechanical ventilation and proved their justification on the field. Nevertheless, it is a major difficulty to collect enough information from the literature to make decisions between different natural ventilation solutions with a given situation and boundary conditions. The current study tests the passive air conduction system (PACS) variations in the design phase of a medium-sized new winery’s cellar and production hall in Villány, Hungary. A computational fluid dynamics simulation based comparative analysis enabled to determine the differences in updraft (UD) and downdraught (DD) PACS, whereby the latter was found to be more efficient. While the DD PACS performed an air change range of 1.02 h−1 to 5.98 h−1, the UD PACS delivered −0.25 h−1 to 12.82 h−1 air change rate. The ventilation performance of the DD version possessed lower amplitudes, but the distribution was more balanced under different wind incident angles, thus this version was chosen for construction. It could be concluded that the DD PACS provides a more general applicability for natural ventilation in moderate climates and in small to medium scale industry hall domains with one in- and one outlet.

Hypothermia and Energy Conservation: A Tradeoff for Elderly Persons?

1989 ◽  
Vol 29 (2) ◽  
pp. 151-161 ◽  
Author(s):  
Susan M. Macey
Keyword(s):  
Energy Conservation ◽  
Thermal Comfort ◽  
Elderly People ◽  
Home Environment ◽  
Accidental Hypothermia ◽  
Elderly Persons ◽  
Residential Energy ◽  
Conservation Measure ◽  
Measure Methods

For many elderly people, residential energy conservation options are often limited to little or no cost measures such as reducing their winter nighttime thermostat setting. As a result, conflicts can arise between the need to preserve health and the necessity to conserve energy. Under these circumstances, accidental hypothermia is an important and growing concern. This study examines the association between concern for health and the adoption by elderly persons of a lowered winter nighttime thermostat setting. Evidence from two surveys of elderly respondents who maintain separate owner-occupied residences shows that health and thermal comfort concerns are the major reasons for nonadoption of this energy conservation measure. Methods are presented for increasing energy conservation while maintaining a healthful home environment.

scholarly journals Estimation of a room ventilation air change rate using a stochastic grey-box modelling approach

Measurement ◽  
2018 ◽  
Vol 124 ◽  
pp. 539-548 ◽  
Author(s):  
Marcel Macarulla ◽  
Miquel Casals ◽  
Núria Forcada ◽  
Marta Gangolells ◽  
Alberto Giretti
Keyword(s):  
Change Rate ◽  
Room Ventilation ◽  
Air Change Rate ◽  
Modelling Approach
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