Backpack blowers are more commonly used by professionals and are mostly powered by 2-stroke gasoline engines. The harness, which has a blower fit into it, is worn on the operator's back. The engine and fan are also placed on the backpack frame with a hand-held hose and spout to direct the airflow. Backpack blowers are powerful, convenient and have larger, more efficient fuel tanks and air filters and therefore, longer duty cycles.
Backpack blowers with more than 40cc engines are the best with a typical blowing power of 400 cfm (cubic feet per minute) of volume at 190 mph (meter per hour). If you live in a quiet neighborhood, these units are the best choice, because they are specially assembled to control unwanted noise. Also, keep in mind that harness quality and comfort differ from one model to the other.
Performance backpack blowers generally have blowing power of more than 450 cfm of volume at 195 mph, and are named because of their high performance. Though they may be noisier than other blowers, they are fast, fuel efficient, and have a quick throttle response. Most professionals and commercial users prefer this type of units, which also has optional accessories like breathable nylon back pads and padded, adjustable harnesses.
The largest and heaviest backpack blower units available are Big-bore Backpacks, with engine powers starting at 50cc. They are also fast and may decrease cleaning time in half. Since these blowers are very powerful, they are typically used for larger areas, and tough jobs like wet matted leaves. They are most suitable for commercial uses.