- THE MAGAZINE
Almost everyone who has performed extraction cleaning has done so with a portable extractor at one time or another. Many have experienced the thrill of moving from portable to truckmount cleaning with its extra power and convenience.
Along with the extra power and features of truckmounts come some unique challenges. One such challenge is hose handling and safety. Many of today's truckmounts are capable of hose runs as long as 300 to 400 feet from the truckmount. While this is excessive in most cases, even runs of 150 feet result in hose running across and through pedestrian areas where tripping and liability could be a problem.
Another related item that is essential in protecting against slips and falls is a simple folding caution sign. These signs are available in different configurations and materials. Most are imprinted with a visual of a person slipping and say "Caution: Wet Floor." Something available from most local distributors, and built specifically for our industry, is a sign with the same picture of a person slipping, but the imprint says, "Caution, Hoses, Wet Carpet." This sign should be used, and be placed next to or over the hose, both on commercial and residential jobs, any time there is a possibility a person will be walking over your hoses. Consider also placing this sign where a person could be walking from wet carpet unto a hard surface. Ask your attorney if he thinks this is a good idea.
Another exciting tool for the professional that can be used with a truckmount, or in many other situations, is the thermo-anemometer. If the weatherman in you has been dying to get out, this is the tool for you. It can read air velocity, temperature, and wind chill. If you would like to put this to a good use in your business, you may want to measure the CFM your truckmount is producing at the end of 150 feet of vacuum hose. Restorers find the thermo-anemometer useful in measuring the air output and temperature from their dehumidifiers and air movers.
The anemometer is placed directly in the airflow, and will give you a reading of how fast the air is moving. For most of our purposes we read this in feet per minute, as we are looking to figure cubic feet per minute of air movement. Measuring in miles per hour and then converting to feet per minute will complicate your math and lead to mistakes.
Calculating your CFM, or cubic feet per meter, is a simple matter of measuring the air speed and multiplying this number by the area it is passing through. This area is at the mouth of the hose or fan. If the airspeed is 6,000 feet per minute, and the area of the mouth of the 2-inch hose is 0.022 square feet, the CFM is figured as 6,000 feet per minute times 0.022 square feet, which equals 132 cubic feet per minute.
A carpet-drying fan opening is a little more difficult, because these tend to be ovals. The best way to calculate the area in this case is to approximate by using a rectangle. The area of a rectangle is length multiplied by height, so measure the height of the opening and multiply it by the length (measure the length as a little bit shorter than the mouth at its longest part). So if the height was 3 inches, and the length is approximately 13 inches, the area (height times length) is 0.27 square feet.
The hardest part in calculating CFM is in keeping the units straight. If you have measured any of your values in inches, you will need to change them to feet before you start calculating. So if the height is 3 inches and the length is 13 inches, change that to 0.25 feet for the height, and 1.08 feet for the length, giving a value of 0.27 square feet for the area.
Take the measurement with the anemometer for feet per minute in several places across the opening of the air mover. Next, take the average of these readings and multiply the feet-per-minute reading by the square feet of the opening to get the CFM: the opening of the air mover is 0.27 square feet times 4,000-feet-per-minute velocity, so the CFM is 1,080.
I hope you find these tools helpful. Like Mom always used to say, "Have fun and be careful!"