PREDICTION OF NATURAL VENTILATION RATES INDUCED BY WEATHER PARAMETERS

摘要

Application of analytical solution is presented for calculating natural ventilation flow rates induced by thermal forces generated by temperature difference together with internal heat sources assisted by solar radiation and wind forces. That solution is applicable to calculate indoor air temperature in case when it is not given, ventilation flow rate and effective opening areas in a single-zone agricultural building with two openings. The method introduces, so called, air change parameters rate α, β and γ to characterise the ventilation flow rates. The first one measures the effect of the thermal buoyancy force on ventilation flow alone. The second, in turn, measures the effect of conductive heat loss out of a building through its envelope. The third one γ assesses the wind force. The effect of all the coefficients on ventilation air rate is defined separately. Parameter β can assume the value lesser than 1 as well as exceeding that value to cover the full range of ventilation flow rates. Heat accumulation is not considered. It is assumed that the indoor air is fully mixed. The model has been applied to the steady state flows.