Effect of Inlet Location on Ventilation Flow Through a Room Fitted With Solar Chimney

Abstract

Solar chimney (thermal chimney) is a device which absorbs solar radiation to heat the air. The heated air, becoming buoyant, rises through the chimney’s passage and induces further air currents. When fitted to a building, solar chimney can thus induce fresh outside air to flow through the building for ventilation. Because only natural means (solar radiation here) are involved to cause the air flow, solar chimney is considered a natural-ventilation device. This work investigates computationally natural ventilation induced by a roof-mounted solar chimney through a real-sized 3-dimensional room, using a commercial CFD (Computational Fluid Dynamics) software package which employs the Finite Volume Method. Chien’s turbulence model of low-Reynolds-number K-ε is used in a Reynolds-Averaged Navier-Stokes (RANS) formulation. Computational domain that includes regions outside the room’s inlet opening and chimney’s exit allows for employing realistic boundary conditions for the computational model. Ventilation rate and air-flow pattern through the room are considered in terms of the location of the room’s inlet opening. It is found that while ventilation flow-rate through the room is higher with the room-inlet opening being located high on the wall opposite to the chimney’s entrance, a room-inlet opening being located near the ground results in better flow pattern with more flow through the living area in the lower part of the room.