Showing 4 results for Energy Saving
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Volume 13, Issue 2 (5-2013)
Abstract
In the combined cooling, heating and power system, electricity is produced by prime mover. Recovered heat from the prime mover supplies heating and cooling demands. In this research, primary energy saving and carbon dioxide emission reduction are employed to evaluate the performances of cchp system compared with conventional system for residential buildings in Tehran. The combined cooling, heatig and power system follows Maximum electrical or thermal demand and Maximum rectangle electrical or thermal demand management. The results indicate that cchp system for residential five, eleven-storey buildings, in maximum rectangle electrical demand, maximum rectangle thermal and maximum electrical demand modes is the best strategy, if cooling demand is produced by absorption chiller and electric chiller. In the best strategy, primary energy saving and carbon dioxide emission reduction are 13% and 12%, respectively. If cooling demand is produced only by absorption chiller, primary energy saving and carbon dioxide emission reduction are decreased. In this case, maximum electrical and thermal demands are the worst strategies. In the worst case, energy consumption and carbon dioxide emission in cchp are increased 39% and 56% compared to the conventional system, respectively. Payback period in these strategies are calculated 5.5 and 7 years for 11 and 5 tories.
Hadi Kargar Sharifabad, Masood Jalilian,
Volume 16, Issue 1 (3-2016)
Abstract
In this article, indicators of annual energy intensity 13 residential complexes with different characteristics were evaluated and compared. These features include the type of facade, heating and cooling systems, windows, and separate or shared type gas meters are units available in the complex. Introducing selected complexes, specifications hull, heating and cooling systems as well as the energy used in the study and analysis of energy flows in the complex have been discussed. The data processing methodology for calculating the energy consumption rate index have been studied conglomerate. The indices are calculated energy intensity of buildings and structures with different properties in terms of energy intensity compared. Compare energy intensity indicators show that the use of new energy Mtalh like metal siding board (decorative panels) instead facade, windows UPVC windows instead of metal, instead of single-wall and double glass instead of heaters and boilers as well as the use of semi-centralized heating systems or room in the building's energy intensity has considerably decreased. Also, instead of using a separate gas meter gas meter joint, by influencing the behavior of the occupants of the building and create a financial incentive to reduce energy use saves natural gas consumption and decreasing energy intensity building.
H. Safikhani, M. Loloee ,
Volume 20, Issue 3 (2-2020)
Abstract
In this paper, multi-objective optimization of the cooling and heating systems at the faculty of engineering of Arak University is investigated to increasing comfort and reducing the cost of energy. In the first step, the faculty building with 4 floors, 11800 square meters of infrastructure and 122 classrooms and rooms is modeled and the comfort and cost of the faculty are calculated. In the next step, a database of 2,000 faculties with different design variables was created and analyzed. Between the formed databases, buildings with the best objective functions are selected and presented in a Pareto front. Design variables are the 11 geometrical and non-geometrical factors affecting the comfort and cost of the faculty. The objective functions are the comfort, cost, and energy consumption. The results indicate that both absorption and compression systems have the ability to achieve acceptable levels of comfort, but the amount of energy consumed in the absorption chiller is higher than the energy consumption of the compression system, which indicates the necessity of using absorption systems in conditions of waste heat. Also, the results indicate that the absorption system, despite the higher energy consumption than the compression system, has lower energy consumption costs due to the difference between electricity and gas tariffs in Iran country and should be corrected.
M. Fallah, Z. Medghalchi,
Volume 20, Issue 6 (6-2020)
Abstract
Recent energy-saving policies in Iran led to more insulation implementation in buildings. Therefore, the occurrence of anti-insulation increases in the building industry. The anti-insulation phenomenon is the reverse function of insulation that causes cooling energy increment rather than energy saving. This phenomenon is an important and effective factor in energy consumption and the resident’s comfort. However, it has not been considered in thermal insulation studies worthily. Therefore, in this study, the anti-insulation occurrence temperature set-point is detected under eight climates of Iran by simulation in the EnergyPlus software. Four thickness of polystyrene insulation is evaluated under three insulating methods including external, mid and internal insulation. Results indicate that the anti-insulation occurs in six climates of Iran. Furthermore, cold and marine climates are more likely to anti-insulation occurrence than hot climates. The anti-insulation happens at a lower temperature by increasing the insulation thickness. In external insulation, due to usage of the wall’s thermal mass, anti-insulation occurs in high temperatures compared with mid and internal insulation methods.
