Cost of Air Conditioner Installation in Illinois$4,084.69 for 2-3 ton unit (using existing ductwork) (Range: $3,527.42 - $4,641.96) Free Estimates from Local ProsCost of Whole House Humidifier Installation in Illinois$397.21 for mid-grade central humidifer (flow-through) (Range: $364.60 - $429.81) Free Estimates from Local ProsCost of Central Air Purifier Installation in Illinois$1,107.63 for a typical two story home (standard grade unit) (Range: $931.75 - $1,283.51) Free Estimates from Local Pros |