Measuring Your Leaf Blower’s Power – CFM vs. MPH
A savvy shopper always wants to get the most bang for their buck. When it comes to leaf blowers, measuring the bang can be a little tricky. You will often times see two numbers describing the power or air flow of a certain blower, the CFM or Cubic Feet per Minute and MPH or Miles Per Hour. Which one should you be looking at and which one is more important?
Realistically both of the numbers are important, and obviously the higher each of the numbers are the more powerful the blower will be. However, these measurements are not equal. To get a better understanding of how well a certain leaf blower will move leaves and debris lets take a look at what each of these numbers actually mean.
Miles Per Hour is a pretty self-explanatory unity of measurement. It is how many miles the air would travel in one hour if the exit velocity remained constant. A lot of manufacturers will boast the MPH of one of their models as the benchmark for power. It makes sense as we are more familiar with this unit of measurement and it tends to hit home with us. When we hear a leaf blower has an air speed of 200 mph we can relate that to a NASCAR driver flying around the track. But measuring the power in terms of MPH does little to describe how well a leaf blower will perform. Try to imagine blowing a little amount of air through a small tube at 200 mph… You’re not going to get much accomplished.
Cubic feet per minute or CFM is probably the first number you will want to look at. It measures the air volume velocity moved through the blower in one minute independent of its density. The engine of the leaf blower powers an impeller, or set of spinning blades in the housing that draws air in one end and forces it out through the tube. The volume of air that exits the tube of the specific model determines the CFM. The more air that moves through the machine the higher the volume, which translates into more leaves moved. However, the volume of air is meaningless if it is not moving fast enough, which is why MPH is also important.
So while you are shopping for a new leaf blower you are going to want to look at both air speed (MPH) and volume (CFM). The higher each of the numbers are the more work will get done in less amount of time. Now that we know what to look for in terms of power, we should take a look at which leaf blowers are going to be the most productive.
There are three main types of leaf blowers: handheld, backpack, and walk-behind. The handheld leaf blower is probably the most common of the three as they are the cheapest and generally least powerful. They come with gas or electric fuel sources with electric coming in corded or cordless versions. You can find handheld blowers with anywhere between under 200 cfm to just under 400 cfm with gas being the more powerful of the two. They work great for small jobs that are under an acre of area. They are also considerably quieter so they are nice if you are working in populated areas.
Backpack blowers are a step up from handheld in terms of power. Most, if not all are powered by gasoline. They typically run from 400 to just over 700 cfm while pushing air speeds of 200 mph. If you have an acre of land or more you will probably want to invest in one of these. You can strap them onto your back, making those longer work sessions a lot more comfortable and efficient.
If you need to get some serious work done you’re going to want to go with a walk-behind leaf blower. These bad boys can push close to 3,000 cfm with air speeds upwards of 250 mph. You can get the biggest, toughest jobs done in no time with a push blower. You can use them for large amounts of leaves (wet or dry), debris, and even clearing small rocks and trash off of parking lots. With the massive amounts of air volume being shot out at high speeds, these are the most powerful types of blowers you can buy.
So next time you’re out shopping for a new leaf blower make sure you get the highest air speed and volume that fit into your budget and needs!