A latent heat storage material which would be useful in hot climate is proposed. It is a mixture of 93-95 wt% commercial Methyl Palmitate (MeP) with 7-5 wt% commercial Methyl Stearate (MeS), having a melting-freezing interval of approximately 23-26.5°C and a latent heat of transition of at least 180kJ/kg.Normal wallboard may be impregnated with up to 25 wt% of one of these mixtures. Air passing over such an impregnated wallboard would be cooled down due to the heat absorption taking place between 23-26.5°C when the mixture melts. Recharging the wallboard will occur at 22-23°C during freezing, when the latent stored heat is released to the cool night air.The total storage capacity of such an impregnated wallboard, in a 3.5°C temperature interval, is at least twelve times higher than the storage capacity of wallboard alone over this range.