Recently builders have shown considerable interest in combining the features of active and passive solar space heating systems into a hybrid system employing active collection and some form of passive discharge/storage device. Ye examined the performance and economics of a hybrid2 air-based, residential system using 18.5 m of roof-mounted air collectors and a hollow-core slab that discharges di...

The conditions of heat source and heat sink in a geothermal ORC system may frequently vary due to variations in geological conditions, ambient temperature and actual operation. In this study, an off-design performance prediction model for geothermal ORC systems is developed according to special designs of critical components, and an optimal control strategy which regards the turbine guide vane ...

The paper examines the effect of the solar chimney’s stack height, depth, width and inlet position on the interior performance (air temperature and speed at 1.20 m height above the ground) as well as proposes an optimal tropical solar chimney design. Simulations show that the output air temperature remains constant while the solar chimney’s width is the most significant factor influencing outpu...

One of basic principles in designing treatment environments is to design air conditioning/ventilation system proportionate to environment. Essentially, appropriate air conditioner in treatment spaces must bear the following capabilities: providing healthy and clean air, reducing the concentration of pollutants produced in the atmosphere, emission of pollutants and impeding their spread in exter...

The heat loads on electronic systems of an unmanned air vehicle are a significant problem. So enhancing transfer is critical key to solve these thermal problems. This study focused increasing rate in crossflow exchanger by using nanofluids numerically. Effects different Reynolds number hot fluid (Re= 6000, 8000, 10000, 12000), inlet velocity (Vair,inlet=30, 45, 60, 90 m/s) cooling fluid, temper...

The purpose of this study was to investigate the effects of head hair on thermoregulatory responses when cooling the head under heat stress. Eight young males participated in six experimental conditions: normal hair (100-130 mm length) and cropped hair (5 mm length) with three water inlet temperatures of 10, 15, and 20°C. The head and neck of subjects were cooled by a liquid perfused hood while...

Mechanical ventilation systems for controlling conditions in individual zones can move a constant or variable supply of conditioned air to handle all or some of the heating and cooling loads. They are classified as all-air, air-water, and all-water systems. All-air systems include single-duct, dual-duct and multizone. The systems can be designed to operate at Constant Air Volume (CAV) or Variab...

An experimental study was carried out to investigate the effects of inlet pressure, sample thickness, initial sample temperature, and temperature sensor location on the surface heat flux, surface temperature, and surface ultrafast cooling rate using stainless steel samples of diameter 27 mm and thickness (mm) 8.5, 13, 17.5, and 22, respectively. Inlet pressure was varied from 0.2 MPa to 1.8 MPa...

Air-Conditioning (AC) systems are responsible for a considerable portion of the energy consumption in buildings located in high cooling load requiring regions of Iran. In addition, the heat flow through the buildingschr('39') external walls plays a major role in cooling load estimations for the countrychr('39')s hot regions. Therefore, application of insulation materials in external walls has g...