Equipping a vacuum with a high-efficiency, HEPA or ULPA filter is a great start to improving indoor air quality, but there are a few other points to consider.

In order to achieve proper filtration, it’s important to know how many filters a vacuum has. Machines with multi-stage filtration pick up the largest particles in the first filtration stage then move to progressively finer filters as dust travels through the unit, capturing smaller and smaller particles. It’s recommended that vacuums be equipped with at least two filters, but some machines feature four or five filtration systems.

In addition to filters, it’s important that the vacuum be a sealed system. Without a sealed design, dust gets released back into the air through gaps in the machine’s body.

Finally, vacuums require sufficient airflow to lift particles from the carpet, as its force is what picks up debris and moves it into the machine. Without adequate airflow and lift, vacuums simply blow dust around. Airflow is measured in cubic feet per minute (CFM) while lift is calculated in inches. These numbers reflect a vacuum’s performance: the higher, the better.


posted on 7/20/2010