Renewable Energy Resources and Technologies
Hadi Farzan
Abstract
Recently, novel techniques have been developed in building industries to use solar heating and cooling systems. The current study develops a Solar-powered Heating and Cooling (SHC) system for an office building in Kerman and assesses the transient dynamics of this system and office indoor temperature. ...
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Recently, novel techniques have been developed in building industries to use solar heating and cooling systems. The current study develops a Solar-powered Heating and Cooling (SHC) system for an office building in Kerman and assesses the transient dynamics of this system and office indoor temperature. To this end, TRNSYS simulation software is utilized to simulate system dynamics. The developed system comprises Evacuated-Tube solar Collectors (ETCs), heat storage tank, heat exchanger, circulating pumps, axillary furnace, cooling tower, single-effect absorption chiller, and air handling unit. The office indoor temperature is assessed in two scenarios, including commonly-insulated and well-insulated envelopes, while window awnings are used to prevent the sun from shining directly through the windows. The results illustrate that the SHC system can meet the thermal loads and provide thermal comfort in line with ASHRAE standards. The indoor temperature reaches 21 °C and 24 °C on cold winter and hot summer days by using the SHC system; however, without the SHC system, the indoor temperature experiences 15 °C and 34 °C on cold and hot days, respectively. The SHC system provides 45 °C and 15 °C supply air on cold and hot days to keep the indoor temperature in the desired range. A thermostat monitors the indoor temperature and saves energy by turning off the system when no heating or cooling is required. Furthermore, the ETCs can run the SHC system for a long time during daytime hours, but the axillary heater is still essential to work at the beginning of the morning.
Advanced Energy Technologies
Mahdi Shakouri; Alireza Noorpoor; Hossein Ghadamian
Abstract
This study presents an analytical method for quantifying the improvement of thermal energy performance of a building integrated photovoltaic double-skin façade. The system was suggested as a retrofit measure for an existing building in Tehran. The effect of thermal performance was analyzed through ...
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This study presents an analytical method for quantifying the improvement of thermal energy performance of a building integrated photovoltaic double-skin façade. The system was suggested as a retrofit measure for an existing building in Tehran. The effect of thermal performance was analyzed through computer-assisted developed codes using Engineering Equation Solver (EES) software. Three scenarios were defined and for each scenario, temperature and velocity profiles were provided through continuity, momentum, and energy equations. Given that the monocrystalline photovoltaic modules and the double-glazed windows are quite common in the current condition in Tehran, the authors considered them for analysis. A comparison of results is valuable for those cases that intend to select either glass or photovoltaic as the outer façade. The quantitative results illustrate that the proposed system would reduce the cooling demand in the summer case by 18.5 kilowatts, which is around 8.7 percent of the current cooling load. According to the results of the sensitivity analysis, both glass and photovoltaic façades were of greater efficiency in terms of energy saving in the summer. By increasing the ratio between the photovoltaic outer façade to the surface area of the glass section, the amount of energy saving due to the total cooling load reduction will increase. The results of the analysis showed that the application of the suggested system would reduce the thermal load by 2.1 percent in the winter season.