scholarly journals Reuse Waste Material and Carbon Dioxide Emissions to Save Energy and Approach Sustainable Lightweight Portable Shelters

2020 ◽  
Vol 24 (1) ◽  
pp. 143-161
Author(s):  
Ammar Alkhalidi ◽  
Yara Nidal Zaytoun
Keyword(s):  
Solar Radiation ◽  
Carbon Dioxide Emissions ◽  
Concrete Slab ◽  
Winter Season ◽  
Thermal Storage ◽  
Thermal Mass ◽  
Night Time ◽  
Lightweight Structures ◽  
Heating Load ◽  
Simulation Results

AbstractDespite their great significance, lightweight structures have poor thermal inertia. In order to enhance the thermal comfort inside such buildings, architects need lightweight thermal storage. In this paper a model was used to experimentally investigate Heating Load profiles in lightweight shelters. The profiles were created for the climate in Jordan, then simulated for other climate zones. The proposed design concept was used to create a replacement for a thermal mass in lightweight structures such as shelters; by combining passive solar gain with energy storage embodied within the shelter floor (thermal-floor) to absorb solar radiation. This shelter design decreased the Heating Load during the winter season by acting as heat storage that releases energy at night time after being exposed to solar radiation during the day. The passive design depends on shading elements and overhangs shades to control solar gain during different seasons to prevent overheating during the summer. An experimental investigation of this model was performed to validate the simulation results. Validated simulation results showed that the designed thermal-floor is 25 % of the total shelter’s floor area, which was crucial for obtaining favourable results. With CO2 as a thermal mass, heat load was reduced up to 68 % compared to a 20 cm concrete slab floor. The use of this thermal storage material yielded a reduction in annual heating demand by 85 kWh/m2.

scholarly journals An Innovative Façade Element with Controlled Solar-Thermal Collector and Storage

2020 ◽  
Vol 12 (13) ◽  
pp. 5281
Author(s):  
Thomas Wüest ◽  
Lars O. Grobe ◽  
Andreas Luible
Keyword(s):  
Solar Radiation ◽  
Thermal Storage ◽  
Thermal Mass ◽  
Building Performance ◽  
Water Tank ◽  
Closed Cavity ◽  
Solar Thermal Collector ◽  
Trombe Wall ◽  
Shading Device ◽  
Heat Transfers

A novel façade element is presented that forms a symbiosis between an enhanced box-type window, a closed cavity façade, and a Trombe wall. This hybrid, transparent-opaque façade element features an absorbing water tank, that is installed behind a controlled shading device toward the cavity of a non-ventilated Double Skin Façade in the parapet section. To evaluate the potential impact on building performance, a transient simulation model is developed in Modelica and calibrated by comparison with measurements on a prototype. The effect of the absorbing thermal storage on heat transfers under solar radiation is analyzed in comparison to (i) conditions excluding solar radiation and (ii) an empty tank. An evaluation for four European cities demonstrates that the annual heating demand can be reduced by more than 4.2% and cooling demand by at least 6.6% compared to a façade without thermal storage. The effect is explained not only by the increased thermal mass, but also by the effective modulation of solar gains by the controlled absorbing storage. The dampening of heat flow fluctuations and the control of solar gains is a promising means to reduce the installed power of HVAC (heating/ventilating/air conditioning) installations.

scholarly journals Experimental Study of Using Thermal Insulation In Buildings Walls To Reduce Heating Load In Al - Kut City

2019 ◽  
Vol 26 (4) ◽  
pp. 30-40
Author(s):  
Sadiq Abdalnabee Kadhm ◽  
Hassan Kareem Abdullah
Keyword(s):  
Experimental Study ◽  
Thermal Insulation ◽  
Winter Season ◽  
Maximum Energy ◽  
Glass Wool ◽  
Air Gap ◽  
Night Time ◽  
South Wall ◽  
Heating Load ◽  
Room Model

Experimental study has been carried out on a small room model constructed from sandwich panel in Al-Kut city to reduce the heating load in winter season. Three types of thermal insulation were used; (Glass wool, Air gap and Sawdust). The room model dimensions were (2m length x2m width x2.4 m height). Room's south wall includes two openings of 0.3m width, 1m height. The first opening is closed by common bricks only, while the second opening is built with double walls from brick separated by thermal insulation of thickness 2cm. The results show that the maximum energy saving of heating load at night time when using thermal insulation were.69%, 58.4%, and 53.6%for glass wool, sawdust and Air gap respectively.

scholarly journals Thermal comfort in winter incorporating solar radiation effects at high altitudes and performance of improved passive solar design—Case of Lhasa

2020 ◽  
Author(s):  
Lingjiang Huang ◽  
Jian Kang
Keyword(s):  
Solar Radiation ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Solar Irradiance ◽  
Indoor Environment ◽  
Thermal Mass ◽  
High Altitudes ◽  
Energy Saving Potential ◽  
Environment Control ◽  
Passive Solar

AbstractThe solar incidence on an indoor environment and its occupants has significant impacts on indoor thermal comfort. It can bring favorable passive solar heating and can result in undesired overheating (even in winter). This problem becomes more critical for high altitudes with high intensity of solar irradiance, while received limited attention. In this study, we explored the specific overheating and rising thermal discomfort in winter in Lhasa as a typical location of a cold climate at high altitudes. First, we evaluated the thermal comfort incorporating solar radiation effect in winter by field measurements. Subsequently, we investigated local occupant adaptive responses (considering the impact of direct solar irradiance). This was followed by a simulation study of assessment of annual based thermal comfort and the effect on energy-saving potential by current solar adjustment. Finally, we discussed winter shading design for high altitudes for both solar shading and passive solar use at high altitudes, and evaluated thermal mass shading with solar louvers in terms of indoor environment control. The results reveal that considerable indoor overheating occurs during the whole winter season instead of summer in Lhasa, with over two-thirds of daytime beyond the comfort range. Further, various adaptive behaviors are adopted by occupants in response to overheating due to the solar radiation. Moreover, it is found that the energy-saving potential might be overestimated by 1.9 times with current window to wall ratio requirements in local design standards and building codes due to the thermal adaption by drawing curtains. The developed thermal mass shading is efficient in achieving an improved indoor thermal environment by reducing overheating time to an average of 62.2% during the winter and a corresponding increase of comfort time.

scholarly journals Energy and Exergy Analysis of a Plane Reflector Integrated Photovoltaic-Thermal Water Heating System

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Prem Sagar Naik ◽  
Arun Palatel
Keyword(s):  
Solar Radiation ◽  
Thermal Water ◽  
Winter Season ◽  
Performance Testing ◽  
Electrical Energy ◽  
Heating System ◽  
Present System ◽  
Exergetic Efficiency ◽  
Water Heating ◽  
Electrical Output

A photovoltaic-thermal water heating system is a hybrid energy conversion device transforming the incident solar radiation to yield electrical energy and thermal energy. Plane reflectors are found to be a convenient option for enhancing the solar radiation incident on the collector plane. The present work investigates the performance of a photovoltaic-thermal water heater integrated with a plane reflector mounted on the top edge of the collector for the tropical climate of Calicut (11.25°N, 75.78°E). Performance testing of the system has been carried out for the winter season of the location. The variations in thermal and electrical output are studied for various inclination angles of the reflector. The system performance is evaluated on the basis of system energy efficiency and exergetic efficiency. It is observed that there is a significant enhancement in the thermal and electrical output of the system with the integration of the reflector as compared to the system without the reflector. For the present system, the reflector tilt angle in the range of 85–100° has been found to be suitable in terms of enhanced system output and exergetic efficiency for the winter conditions of Calicut.

scholarly journals Carbon dioxide fluxes increase from day to night across European streams

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Katrin Attermeyer ◽  
Joan Pere Casas-Ruiz ◽  
Thomas Fuss ◽  
Ada Pastor ◽  
Sophie Cauvy-Fraunié ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Large Scale ◽  
Carbon Dioxide Flux ◽  
Time Of Day ◽  
Night Time ◽  
Carbon Dioxide Fluxes ◽  
Large Scale Assessment ◽  
Air Interface ◽  
Flux Variability

AbstractGlobally, inland waters emit over 2 Pg of carbon per year as carbon dioxide, of which the majority originates from streams and rivers. Despite the global significance of fluvial carbon dioxide emissions, little is known about their diel dynamics. Here we present a large-scale assessment of day- and night-time carbon dioxide fluxes at the water-air interface across 34 European streams. We directly measured fluxes four times between October 2016 and July 2017 using drifting chambers. Median fluxes are 1.4 and 2.1 mmol m−2 h−1 at midday and midnight, respectively, with night fluxes exceeding those during the day by 39%. We attribute diel carbon dioxide flux variability mainly to changes in the water partial pressure of carbon dioxide. However, no consistent drivers could be identified across sites. Our findings highlight widespread day-night changes in fluvial carbon dioxide fluxes and suggest that the time of day greatly influences measured carbon dioxide fluxes across European streams.

scholarly journals Evaluating the Effect of External Horizontal Fixed Shading Devices’ Geometry on Internal Air Temperature, Daylighting and Energy Demand in Hot Dry Climate. Case Study of Ghardaïa, Algeria

Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 348
Author(s):  
Sahar Magri Elouadjeri ◽  
Aicha Boussoualim ◽  
Hassan Ait Haddou
Keyword(s):  
Solar Radiation ◽  
Parametric Analysis ◽  
Energy Demand ◽  
Daylighting Simulation ◽  
Simulation Results ◽  
Shading Devices ◽  
Heating Loads ◽  
Shading Device ◽  
The City

The present study investigates the effect of fixed external shading devices’ geometry on thermal comfort, daylighting and energy demand for cooling and heating in the hot and dry climate of the city of Ghardaïa (Algeria). A parametric analysis was performed by using three software: RADIANCE 2.0 and DAYSIM 3.1 for daylighting simulation and TRNSYS.17 for thermal dynamic simulation. Three shading device parameters were assessed: the spacing between slats, the tilted angle and the slats installation. The vertical shading angle “VSA” is fixed; it is equal to the optimum shading angle measured for Ghardaïa. The simulation results indicate that fixed external shading devices have a significant impact on decreasing the energy demand for cooling; however, they are unable to reduce the total energy demand since they significantly increase heating loads. It was found that fixed external shading devices remove all risks associated with glare in summer by decreasing illuminance close to the window; however, they do not improve daylighting performance in winter because of glare. We note that even if the vertical shading angle “VSA” was the same for all cases, these did not present the same thermal and luminous behavior. This is mainly due to the amount and the way that the solar radiation penetrates space.

ASSESSMENT OF ROAD LIGHTING PERFORMANCE FOR TRAFFIC INTENSITY AND TRAFFIC DETECTION BASED LIGHTING ADAPTATION

2021 ◽  
Author(s):  
D. Gasparovsky ◽  
P. Janiga
Keyword(s):  
Carbon Dioxide Emissions ◽  
Energy Performance ◽  
Assessment System ◽  
Traffic Intensity ◽  
Night Time ◽  
Road Lighting ◽  
Emissions Mitigation ◽  
Urban Settlements ◽  
European Standards ◽  
Traffic Detection

Amongst many road lighting design criteria, energy performance plays an important role as it has a direct link to operational costs, potential reduction of carbon dioxide emissions, mitigation of obtrusive light, and its impact on the night-time environment in urban and con-urban settlements. The energy energy performance of road lighting is conveniently described by the pair of normative numerical indicators PDI and AECI established in European standards. This paper aims to present typical values of the AECI (Annual Energy Consumption Indicator) for different combinations of road arrangements, road widths, lighting classes and light source technologies to illustrate what benchmarks can be expected using this assessment system. Essential part of this paper is focusing on assessment of the performance for traffic intensity and traffic detection based lighting adaptation.

scholarly journals Discussion on the Reinforcement of Reinforced Concrete Slab Structures

2019 ◽  
Vol 11 (6) ◽  
pp. 1756 ◽  
Author(s):  
Wei-Ling Hsu ◽  
Chen-Chung Liu ◽  
Yan-Chyuan Shiau ◽  
Wen-Chin Lin
Keyword(s):  
Epoxy Resin ◽  
Carbon Dioxide Emissions ◽  
Environmental Changes ◽  
Concrete Slab ◽  
Salt Content ◽  
Protective Layer ◽  
Chloride Ions ◽  
Structural Safety ◽  
Reinforced Concrete Slab ◽  
Short Side

Because of global environmental changes and the continued warming of the planet, the increase in carbon dioxide emissions has had a major impact on the environment. The development of zero-carbon buildings, the promotion of energy conservation and carbon reduction, and the concept of green environmental protection are regarded as important issues for humanity to achieve sustainable development. In Taiwan, the combination of moisture and high salt content in the environment, corrosion caused by chloride ions, and earthquakes often lead to the formation of crevices in buildings. These crevices can cause rebar oxidation and corrosion and even concrete structure damage or spalling. Conventional structural damages can be repaired with epoxy resin grout. However, such practices are incapable of removing the rusted components of the rebars inside the structures and thus subject the internal rebars to continuous oxidation in the original rust-covered environment. Components located deep within the structures would still swell as a result of continuous rebar oxidation and cause concrete breaking and spalling, making previous repair efforts ineffective. This study proposes an improved repair and retrofit technique that includes the removal of rust from oxidated rebar parts, by applying low viscosity epoxy resin to the slab base and allowing it to fully penetrate the concrete cracks and surface of the rebars inside, thus producing a protective layer and repairing the bond. Additionally, carbon-fiber reinforced plastic (CFRP) patches were adopted as repair materials and attached to the beams and slab (ceiling) surfaces. Angle steels were used at the edges and installed to connect the beams to the slab with chemical anchors. The gaps between the angle steels and the slab were filled with epoxy resin grouts. On the short side of the slab, small steel H-beams were installed 1 m apart as a means of retrofit. Because the epoxy resin expands by 8% after undergoing chemical reactions, it bonds perfectly with concrete, CFRP patches, and steel materials. Approximately 10 years have elapsed since the case-study was repaired using the proposed technique, and the retrofit effect has yielded excellent results to the present day, with no occurrence of internal swelling or spalling from rebar oxidation. The proposed retrofit technique can reduce construction costs, while ensuring effective repair and maintenance of structural safety, and extend the service life of structures.

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