Abstract: A typical embodiment of the invention reduces the load on an air conditioner and provides more efficient evaporative cooling, humidification and filtering. Improved cooling and humidification is the result of an ultrasonic fog generator which reduces liquid droplet size to about ten microns for flash evaporation. A silica-containing filter, moreover, has an affinity for mechanically unfilterable residual calcium-containing particulate matter that is entrained in the humidified air, in order to extract this matter from the treated air.