Best, better and bad filters

Even a good vacuum cleaner is nothing without a good filter. Before buying a new vacuum cleaner, find out what kind of filter it takes.

Ultra low penetration air filter. Called “ULPA” for short, this is the highest-quality filter you can use, though it's mostly for industrial-grade machines in places like museums, hospital operating rooms and industrial cleanrooms. ULPA filters block particles as small as 0.12 micrometers with an efficiency rate of 99.999 percent, according to AgriLife, a life sciences research facility at Texas A&M University.

HEPA filters. A HEPA (high efficiency particulate air) filter blocks particles as small as 0.3 micrometers — the size of a single speck of corn starch — with an efficiency rate of 99.97 percent, AgriLife reports. Though it can be expensive, it’s a good choice for household use because it traps most of hazardous particles found in the home, such as bacteria, mold, pollen and fungus.

Micron filter. Also called an electrostatic filter or a HEPA-type filter, these have a similar construction to HEPA filters but they don’t meet the same quality specifications. Look for one with an efficiency rate of 98 percent.

Non-HEPA or non-HEPA-type air filter. These low-quality filters trap particles only as small as 30 to 50 micrometers — hair, dusts mites, and only the largest types of pollen and bacteria. If this is the kind of filter in your vacuum (call the manufacturer or check your owner’s manual for details) and you’re concerned about how your indoor air affects your health, you may want to upgrade.

You might be able to change out the filter for a better one, but if you have a cheap vacuum, even a better filter might not help if the machine is not well sealed. Some leak dust and particles through the sides of the machine.

Finally, a note on bags: If you have a bag-type vacuum, look for micro-lined bags treated with an anti-bacterial agent, advise experts at the University of Illinois College of Agricultural, Consumer and Environmental Sciences (ACES).