Comparison between Natural and Hybrid Ventilation for Hot Climate by Using CFD
This paper presents mathematical study by using computer simulation program (ANSYS), in order to measure the effect of ceiling and wall fans in decreasing air temperature during night time in Aswan, Egypt (latitude 24° N), Where the indoor temperature exceeds the thermal comfort through overheated period. Heat gain of the high mass building during the day time increases the indoor temperature at the night time. As a result, the indoor temperature becomes higher than the outdoor temperature at the night time in summer. Simulation study for three experimental models according to ventilation conditions. The first model that depends on cross ventilation (cross ventilation model), the second model is hybrid ventilation that consists of natural ventilation (cross ventilation) and mechanical ventilation (ceiling fan), the third model is same as second model but using wall fan instead of ceiling fan. The boundary conditions are according to Aswan weather in overheated period. Simulation results of cross ventilation and hybrid ventilation models decreased indoor temperature from 5 ºC to 8.5 ºC in case of outdoor temperature is 27°C during night time, while indoor temperature is 38°C. The wall fan enhances indoor air flow more than the ceiling fan and air flow is well-distributed inside the room at sitting level.
Comfort Ventilation, Cross Ventilation, Ceiling and Wall Fans, Computational Fluid Dynamic (CFD), Aswan, Egypt
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