The purpose of this study is to predict the safe storage height of coal stockpiles. To accomplish this, a one dimensional non - steady - state model with the effect of stockpile height approximated by a heat sink in the one dimensional energy equation has been develepod. The model consists of conservation equations for oxygen, water vapour, inherent moisture of the coal, and energy for both gaseous and solid phases. The heal sink term taken from literature is based on an assumed sinusoidal variation in temperature in the vertical direction.