Knowledge of room air distribution, including its flow and temperature characteristics, is very important to HVAC engineers. This study numerically predicts the air distribution in a room with differentially heated vertical walls. The Rayleigh number in the room is around 2.6-3x 1010. Time averaged equations of continuity, momentum, and energy are numerically solved by the finite volume method. Three turbulence models, the "standard" k-E model, and two low-Reynolds-number k-E models, are employed to simulate turbulent natural convection in the room.
Thermal comfort in a naturally ventilated test room is investigated. The test room is a lightweight portable cabin located in a sheltered area at Loughborough University, UK. Thermal comfort simulations were carried out for various sizes of openings and glazing. Medium and high thermal mass were added to the test room and their effects on thermal comfort were investigated. The results suggested that thermal mass has significant effect on thermal comfort parameters. Adding a 200 mm thick layer of medium-density concrete to the walls improved the thermal comfort over the summer by 40%.
The authors' previous analysis of dynamic insulation is extended to include the inner and outer air film resistances with the objective of modelling the variation in surface temperature with air flow. The boundary condition that comes closest to predicting the variation of the surface temperature with air flow is one which assumes that the conduction heat flux at the wall surface, rather than the net heat flux, is equal to the flux incident on the wall from global environmental temperature, T.;.
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