Customer collects and incinerates garbage. When they first start up the furnaces the flue stacks are cold and do not draft properly. Installing a Model 121021 High Temperature Air Amplifier onto one end of an elbow, then running the other end of the elbow trough the wall of the flue stack and centering in the middle, high velocity air from the air amplifier was directed up through the stack. This provided the proper draft until the stack warmed up and natural draft was established. At that point the compressed air was turned off to the air amplifiers. The high temperature qualities of the High Temperature Air Amplifier enabled it to resist the heat transferred to it while in the dormant mode.