Some Importatn Tersm and Definition:
CFM (Air Flow)
Cubic Feet (of air) per Minute.
For moving dusts and pebble in the vacuum pipes you need a sufficient air flow that is crucial for any types of deep cleaning. CFM (Air flow) it’s an important measurement on evaluating central vac power and simply means how much air in a round two inch pipe.
Central vacuums don't vacuum the wet stuff, but this benchmark specification is calculated using water. As you know central vacuums do not vacuum wet stuff but Water-Lift benchmark helps us to understand how many inches up a tube the vacuum motor’s intake can pull up water. Actually it shows the power of motor for suctioning the water but the measurement is done by sealed suction but please remember that the water lift is important but not as much as CFM (Air flow).
The water-lift of a vacuum is what is used when lifting a bowling ball, as seen in some commercials. It is amazing what you can do when all the power of the vacuum is focused on one surface.
The measurements that are introduced above are known as the maximum capacity of central vacuum unit but what about the real operation when you put the system under pressure?
For understanding the real power and functionality of vacuum cleaners we use another measurement that is Air Watt is a calculated measurement which is considered CFM and water-lift at the real operating end of the vacuum hose.
The concept used to compute air wattage differs between vacuum cleaner manufacturers. The standard air watt formula is from ASTM International:
P: Power in air watts
F: Rate per minute (denoted cu ft/min or CFM)
S: Suction capacity expressed as a pressure in units of inches of water.
That makes one air watt= 0.9983 watts, which rounds off to 1.0 watts
The air pressure around us is about 400 inches of water. That means that every surface has the equivalent of 400 inches of water pushing on that surface. A vacuum cleaner actually use the pressure difference between normal air pressure and the pressure inside the pipes which create cleaning function.
To remove dust in vacuum systems, a function called air cone rotation is also known as tornado performance is used and In a tornado operation, air flows blows through a conical container from top to bottom and vice versa to remove dust from the system at the bottom of the cone and absorb by embedded filters.
Measured in revolutions per minute (RPM).
Otherwise known as the "Measure of Fan Efficiency" is Air Watts / Input Watts and it shows the productivity of VC unit.
Paper Filter Bag
This is a device for collecting dust and debris used by few vacuum cleaner manufacturers. Paper bags, in our opinion, are the best way to filter debris, have a safe and healthy disposal, and a very clean exhaust.
Amp – an ampere is the unit for measuring electricity. The accepted standard unit used for measuring how fast electric current flows is an example of an ampere.
This is a core part of the motor that rotates, and transfers of electricity across the motor and also enabling the motor shaft to spin. A quality armature is installed on ball bearings, and protected from incoming air.
Central vacuum cleaner engines require separate cooling operations from the airflow provided by the vacuum cleaner itself, which is provided by cooling fans that is called bypass cooling system.
Watts to Amps (Conversion)
The conversion of watts to amps is governed by the equation Amps = Watts / Volts. So if a motor draws 3000 watts at 120 volts it will pull 25 amps. If you have the amps and volts you can multiply them to get the watts by this formula; W=V.A