Your vacuum cleaner, or most of the upright or canister ones you may want to purchase, are 8- to 12-amp vacuum cleaners. The household outlet you plug your vacuum cleaner into accommodates a maximum of 15 or 20 amps depending on the circuit, but 12 amps are the maximum allowed for UL approval, so you won't find any vacuum cleaners with more than 12 amps.
Why Amps Aren't a Reliable Indicator of Suction Power
Amps measure the power of the electrical current going from your outlet to the motor of your vacuum cleaner. While many vacuum cleaners have "12 amps" prominently displayed on their advertising material, having a 12-amp vacuum cleaner doesn't mean you have the most powerful cleaner on the market. It's up to the manufacturer to design a motor that uses the amps productively. Some 12-amp vacuum cleaners clean better than other 12-amp vacuum cleaners.
There are several factors other than amperage that influence the cleaning power of a vacuum cleaner.
Other Factors That Influence Suction Power
- The design of the motor affects performance. Some vacuums have two or three fans that work together rather than a single fan. This improves suction power.
- The condition of the filters and the way the system filters dirt influences cleaning power. Washable filters should be cleaned following the manufacturer's recommendations for optimum airflow.
- Hose and nozzle design and quality affect performance.
- Height adjustment on the carpet or surface.
- Emptying the canister or bag when it is full is important. Suction is dramatically reduced when the canister is full.
- The airflow specification affects the cleaning ability of the vacuum. It is measured in cubic feet per minute (CFM). The more airflow the unit has, the better the cleaning ability of the vacuum cleaner.