scholarly journals Seasonal Performance Analysis of Three Air Cooling Systems for School Buildings

2021 ◽  
Vol 9 (1) ◽  
pp. 14
Author(s):  
María Jesús Romero-Lara ◽  
Francisco Comino ◽  
Manuel Ruiz de Adana
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Climatic Conditions ◽  
Air Cooling ◽  
School Buildings ◽  
Direct Expansion ◽  
Cooling Systems ◽  
Seasonal Performance ◽  
Evaporative Cooler ◽  
Conventional Systems

Efficient air cooling systems for hot climatic conditions, such as southern Europe, are required. Regenerative indirect evaporative cooler (RIEC) and desiccant regenerative indirect evaporative cooler (DRIEC) could be interesting alternatives to direct expansion conventional systems (DX). The main objective of this work was to evaluate the seasonal performance of three air cooling systems in terms of thermal comfort, ventilation and energy consumption. DRIEC was the recommended system to serve a standard classroom in terms of thermal comfort and RIEC in terms of ventilation and energy consumption.

scholarly journals Seasonal Analysis Comparison of Three Air-Cooling Systems in Terms of Thermal Comfort, Air Quality and Energy Consumption for School Buildings in Mediterranean Climates

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4436
Author(s):  
María Jesús Romero-Lara ◽  
Francisco Comino ◽  
Manuel Ruiz de Adana
Keyword(s):  
Energy Consumption ◽  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Mediterranean Area ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Cooling Systems ◽  
Climate Zones

Efficient air-cooling systems for hot climatic conditions, such as Southern Europe, are required in the context of nearly Zero Energy Buildings, nZEB. Innovative air-cooling systems such as regenerative indirect evaporative coolers, RIEC and desiccant regenerative indirect evaporative coolers, DRIEC, can be considered an interesting alternative to direct expansion air-cooling systems, DX. The main aim of the present work was to evaluate the seasonal performance of three air-cooling systems in terms of air quality, thermal comfort and energy consumption in a standard classroom. Several annual energy simulations were carried out to evaluate these indexes for four different climate zones in the Mediterranean area. The simulations were carried out with empirically validated models. The results showed that DRIEC and DX improved by 29.8% and 14.6% over RIEC regarding thermal comfort, for the warmest climatic conditions, Lampedusa and Seville. However, DX showed an energy consumption three and four times higher than DRIEC for these climatic conditions, respectively. RIEC provided the highest percentage of hours with favorable indoor air quality for all climate zones, between 46.3% and 67.5%. Therefore, the air-cooling systems DRIEC and RIEC have a significant potential to reduce energy consumption, achieving the user’s thermal comfort and improving indoor air quality.

Assessments of High-Efficient Regenerative Evaporative Cooler Effects on Desiccant Air Cooling Systems

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Hakan Caliskan ◽  
Dae-Young Lee ◽  
Hiki Hong
Keyword(s):  
Cooling System ◽  
Dew Point ◽  
Air Cooling ◽  
Sensible Heat ◽  
Cooling Systems ◽  
High Efficient ◽  
Air Cooling System ◽  
Evaporative Cooler ◽  
Effectiveness And Efficiency ◽  
And Performance

Abstract In this paper, the effects of regenerative evaporative coolers on the dry desiccant air cooling system are assessed. Thermodynamic analysis is performed point by point on the unmodified (ɛ = 0.67) and modified (ɛ = 1) regenerative evaporative cooler supported systems. It is found that the effectiveness and efficiency of the system were significantly increased by modification. Effectiveness of the system increases from 0.95 to 2.16 for the wet bulb and from 0.63 to 1.43 for dew point effectivenesses, while the exergy efficiency increases from 18.40% to 41.93%. Exergy and energy performances of the system increase 1.28 times and 0.61 times, respectively. Finally, sustainability is increased by 40% with the modification of the regenerative evaporative cooler. Also, changing the regenerative evaporative cooler of the solid desiccant wheel with the effective one can increase the overall system efficiency and performance without changing the sensible heat and desiccant wheels.

Analysis of Running Energy Consumption of Fresh Air Cooling Systems

Solar Energy ◽  
2005 ◽  
Author(s):  
Jianing Zhao ◽  
Jun Guo ◽  
Weimeng Sun
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Cooling System ◽  
Air Cooling ◽  
Total Energy Consumption ◽  
Cooling Systems ◽  
Variable Air Volume ◽  
Air Volume ◽  
Air System ◽  
Different Seasons

Utilization of renewable energy becomes more and more attractive and crucial for sustainable buildings. A cooling system, using outdoor fresh air and combining with the conventional all-air system or running along during different seasons, is discussed in this study. Running energy consumption of this system is analyzed by a mathematical model using the Genetic Algorithm (GA) combined with the traditional Lagrange method. To evaluate and apply this new system, energy consumption of the chiller unit, water and air sub-systems, as well as the total energy consumption of such a system is compared with that of the conventional all-air system. Consequently, the total energy consumption is selected as the criterion of energy efficiency. The results show that the cooling system bears considerably energy efficient, and that it reduces energy consumption at least 14% and 12%, compared with the constant air volume and variable air volume system, respectively.

scholarly journals Analysis of the Effect of Using External Venetian Blinds on the Thermal Comfort of Users of Highly Glazed Office Rooms in a Transition Season of Temperate Climate—Case Study

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 81 ◽  
Author(s):  
Małgorzata Fedorczak-Cisak ◽  
Katarzyna Nowak ◽  
Marcin Furtak
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Ambient Air ◽  
Temperate Climate ◽  
Cooling Systems ◽  
Clothing Insulation ◽  
Transition Season ◽  
Venetian Blinds ◽  
Research Task ◽  
Office Rooms

Improving the energy efficiency of buildings is among the most urgent social development tasks due to the scale of energy consumption in this industry. At the same time, it is essential to meet high requirements for indoor environmental quality and thermal comfort. The issue of overheating is most often analysed in summer but it also occurs in transition seasons, when the cooling systems do not operate. The paper attempts to evaluate the effectiveness of external mobile shading elements on the microclimate of rooms with large glazed areas in the transition season. Passive solutions, such as shading elements, which limit the increase of indoor temperature, do not always allow the acquisition and maintenance of comfortable solutions for the duration of the season, as demonstrated by the authors. Temporary cooling of the rooms may be necessary to maintain comfortable conditions for the users, or other solutions should be devised to improve comfort (e.g., reduction of clothing insulation characteristics). The novelty of the study consists in the analysis of comfort in a “nearly zero energy consumption” building (NZEB) during a period not analyzed by other scientists. This is a transition period during which heating/cooling systems do not operate. The research task set by the authors involved the assessment of the possibility to reduce office space overheating in the transition season (spring) by using external shading equipment in rooms with large glazed areas. An additional research task aimed at checking the extent to which user behaviour, such as reduction in clothing insulation characteristics, can improve comfort in overheated rooms. The results of the tests reveal that the difference in the ambient air temperature between a room with external venetian blinds and an identical room with no venetian blinds in the transition season, i.e., from 27 March to 6 April 2017, ranged from 12.3 to 2.1 °C. The use of a shading system (external venetian blinds positioned at an angle of 45°) reduced the number of discomfort hours by 92% (during working hours) compared to the room without external venetian blinds. A reduction in the thermal insulation of the clothes worn by people working in the room with no venetian blinds helped to reduce the number of discomfort hours by 31%.

scholarly journals Innovative Turbine Intake Air Cooling Systems and Their Rational Designing

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6201
Author(s):  
Andrii Radchenko ◽  
Eugeniy Trushliakov ◽  
Krzysztof Kosowski ◽  
Dariusz Mikielewicz ◽  
Mykola Radchenko
Keyword(s):  
Gas Turbines ◽  
Maximum Rate ◽  
Cooling System ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Thermal Loads ◽  
Cooling Systems ◽  
Air Cooling System

The efficiency of cooling ambient air at the inlet of gas turbines in temperate climatic conditions was analyzed and reserves for its enhancing through deep cooling were revealed. A method of logical analysis of the actual operation efficiency of turbine intake air cooling systems in real varying environment, supplemented by the simplest numerical simulation was used to synthesize new solutions. As a result, a novel trend in engine intake air cooling to 7 or 10 °C in temperate climatic conditions by two-stage cooling in chillers of combined type, providing an annual fuel saving of practically 50%, surpasses its value gained due to traditional air cooling to about 15 °C in absorption lithium-bromide chiller of a simple cycle, and is proposed. On analyzing the actual efficiency of turbine intake air cooling system, the current changes in thermal loads on the system in response to varying ambient air parameters were taken into account and annual fuel reduction was considered to be a primary criterion, as an example. The improved methodology of the engine intake air cooling system designing based on the annual effect due to cooling was developed. It involves determining the optimal value of cooling capacity, providing the minimum system sizes at maximum rate of annual effect increment, and its rational value, providing a close to maximum annual effect without system oversizing at the second maximum rate of annual effect increment within the range beyond the first maximum rate. The rational value of design cooling capacity provides practically the maximum annual fuel saving but with the sizes of cooling systems reduced by 15 to 20% due to the correspondingly reduced design cooling capacity of the systems as compared with their values defined by traditional designing focused to cover current peaked short-term thermal loads. The optimal value of cooling capacity providing the minimum sizes of cooling system is very reasonable for applying the energy saving technologies, for instance, based on the thermal storage with accumulating excessive (not consumed) cooling capacities at lowered current thermal loads to cover the peak loads. The application of developed methodology enables revealing the thermal potential for enhancing the efficiency of any combustion engine (gas turbines and engines, internal combustion engines, etc.).

Systematic Assessment of Combustion Turbine Inlet Air-Cooling Techniques

2005 ◽  
Vol 127 (1) ◽  
pp. 159-169 ◽  
Author(s):  
Abdalla M. Al-Amiri ◽  
Montaser M. Zamzam
Keyword(s):  
Air Temperature ◽  
Evaporative Cooling ◽  
Heat Rate ◽  
Climatic Conditions ◽  
Coefficient Of Performance ◽  
Air Cooling ◽  
Cooling Systems ◽  
Turbine Inlet ◽  
Wide Range ◽  
The Impact

The current study is centered on assessing the benefits of incorporating combustion turbine inlet air-cooling systems into a reference combustion turbine plant, which is based on a simple cycle under base load mode. Actual climatic conditions of a selected site were examined thoroughly to identify the different governing weather patterns. The main performance characteristics of both refrigerative and evaporative cooling systems were explored by examining the effect of several parameters including inlet air temperature, airflow-to-turbine output ratio, coefficient of performance (for refrigerative cooling systems), and evaporative degree hours (for evaporative cooling systems). The impact of these parameters was presented against the annual gross energy increase, average heat rate reduction, cooling load requirements and net power increase. Finally, a feasibility design chart was constructed to outline the economic returns of employing a refrigerative cooling unit against different prescribed inlet air temperature values using a wide range of combustion turbine mass flow rates.

scholarly journals Evaluation of School Building Energy Performance and Classroom Indoor Environment

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2489 ◽  
Author(s):  
Jitka Mohelníková ◽  
Miloslav Novotný ◽  
Pavla Mocová
Keyword(s):  
Energy Consumption ◽  
Energy Performance ◽  
Climatic Conditions ◽  
School Buildings ◽  
School Building ◽  
Indoor Climate ◽  
Building Stock ◽  
Building Envelopes ◽  
Existing Building ◽  
School Renovation

Existing building stock represents potential for energy saving renovations. Energy savings and indoor climate comfort are key demands for sustainable building refurbishment. Especially in schools, indoor comfort is an extremely important issue. A case study of energy consumption in selected school buildings in temperate climatic conditions of Central Europe region was performed. The studied buildings are representatives of various school premises constructed throughout the last century. The evaluation was based on data analysis of energy audits. The goal was aimed at assessment of the school building envelopes and their influence on energy consumption. One of the studied schools was selected for detailed evaluation. The school classroom was monitored for indoor thermal and visual environments. The monitoring was performed to compare the current state and renovation scenarios. Results of the evaluation show that the school buildings are highly inefficient even if renovated. Indoor climate in classrooms is largely influenced by windows. Solar gains affect interior thermal stability and daylighting. Thermal insulation quality of building envelopes and efficient solar shading systems appear to be fundamental tasks of school renovation strategies.

Energy efficiency of PCM integrated in fresh air cooling systems in different climatic conditions

2018 ◽  
Vol 212 ◽  
pp. 976-996 ◽  
Author(s):  
Octavian G. Pop ◽  
Lucian Fechete Tutunaru ◽  
Florin Bode ◽  
Ancuţa C. Abrudan ◽  
Mugur C. Balan
Keyword(s):  
Energy Efficiency ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Cooling Systems

Gas turbine intake air cooling systems of combined type and their optimum designing

2020 ◽  
Vol 5 (2) ◽  
pp. 3-24
Author(s):  
Andrii M. Radchenko ◽  
Keyword(s):  
Low Temperature ◽  
Lithium Bromide ◽  
Climatic Conditions ◽  
Temperate Climate ◽  
Air Cooling ◽  
Fuel Saving ◽  
Cooling Systems ◽  
Exhaust Heat ◽  
Refrigeration Capacity ◽  
Cooling Air

Turbine intake air cooling (TIAC) by absorption lithium-bromide chillers (ACh) utilizing the exhaust heat is considered as the most effective fuel saving technology for temperate climatic conditions. But the cooling potential of TIAC systems based on ACh of a simple cycle is limited by a comparatively increased chilled water temperature of about 7°C excluding cooling intake air lower than 15°C. The application of a refrigerant as a coolant enables deeper cooling intake air to 10°C and lower. The application of two-stage hybrid absorption-ejector chillers (AECh) with a refrigerant ejector chiller (ECh) as a low temperature stage makes it possible to increase the annual fuel saving approximately twice in temperate climate due to deeper cooling air as compared with ACh. Furthermore, this effect can be achieved with the sizes of TIAC system reduced by about 20 % due to determining the rational refrigeration capacity of AECh providing practically maximum annual fuel saving increment and the use of the current excessive refrigeration capacities to cover peaked loads.

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