Vacuum cleaners manufacturers (and retailers) often try to persuade the prospects to buy their products talking about their amperage (or wattage).
Typically the sales guys say something like „…buy this vac, it has an extra strong 12 Amps motor providing great suction…“. Yet, the truth is that amount of amperes or watts the vacuum cleaner takes from an electric outlet has almost nothing to do with vacuum´s suction power.
To explain it, first, let´s get back to grammar school.
The strength of an electric current is measured in amperes. One ampere is the amount of current that flows through one ohm of resistance with one volt applied. On the other hand, watt is the unit of electric power. One watt of power is used when one ampere of current flows through a resistance of one ohm.
Complicated? Don´t bother with it, you will never need it.
Sure, it is important how much power your vacuum cleaner consumes ( if you want to save on energy bills) but if you are looking for a really strong vacuum cleaner forget about amperage or wattage and ask the salesman how many air watts the vac features and what´s its airflow.
While any strong vacuum cleaner can consume 1700 Watts its actual suction power only will be 320 – 420 Watts which means the suction efficiency is 19 – 25% (the most efficient vacuums can exceed 30%).
How to calculate watts from amperes (and vice cersa)
As the American vacuum manufacturers use amperage and manufacturers from Europe use wattage when describing the vacs´power consumption, it may quite impossible for a prospective customer to compare such products and evaluate their parameters.
Comparing amperes to watts is like comparing apples with pears. No, actually it´s like comparing peanuts with pears so in order to get an overview you need to recalculate them to compare peanuts with peanuts OR pears with pears.
To calculate watts from amps just multiply number of amperes by approximately 110.
To convert amps to watts just divide watts by approx. 110. That´s all, you´re comparing the right fruits to each other…
Amperes, Wats and Air Watts
To make it even easier for all of us, following chart can be applied when comparing the power consumption of vacuum cleaners. I am multiplying amperes by 110 (sharp) to get the wattage so I expect that some accuracy lovers will raise their hands but I think we will not neetd an absolutely accurate number for this purpose.
I also added the expected suction power and I suppose that 90% of all current vacs will not exceed this range (at least not now, which is July 2007). Here we go…
5 Amp US vacuum cleaner equals to 550W European vac. The expected suction power is 105 - 138 Air Watts.
6 Amp US vacuum cleaner equals to 660W European vac. The expected suction power is 125 - 165 Air Watts.
7 Amp US vacuum cleaner equals to 770W European vac. The expected suction power is 146 - 193 Air Watts.
8 Amp US vacuum cleaner equals to 880W European vac. The expected suction power is 167 - 220 Air Watts.
9 Amp US vacuum cleaner equals to 990W European vac. The expected suction power is 188 - 248 Air Watts.
10 Amp US vacuum cleaner equals to 1100W European vac. The expected suction power is 209 - 275 Air Watts.
11 Amp US vacuum cleaner equals to 1210W European vac. The expected suction power is 230 - 303 Air Watts.
12 Amp US vacuum cleaner equals to 1320W European vac. The expected suction power is 251 - 330 Air Watts.
We will stop here as 12 Amps is the US limit for maximum amount of electricity pulled out of a wall socket.
EU doesn´t have such limits (at least I am not aware of any) and you can easily buy 1900W vacuums here (17.3 Amps).