Professional cleaning technicians hear the term "HEPA" in reference to vacuum cleaners much more today than ever before. However, not everyone seems to know what HEPA actually is or does or how it can benefit them, their customers, and the locations they clean.
HEPA stands for high-efficiency particulate air. The first HEPA filters were developed in the 1940s by the United States Atomic Energy Commission to fulfill a top-secret need for efficient, effective ways to filter radioactive particulate contaminants. After World War II, the technology was released to the general public for commercial and residential use.
A HEPA filter can remove 99.97 percent of particles 0.3 microns in size or larger. To comprehend just how small that is, the period at the end of this sentence is about 500 microns in diameter.
"HEPA filters are now considered the best form of air-filtration system available," says James Hlavin, director of sales at Tornado Industries. "You'll see them used in the HVAC (heating, ventilating, and air-conditioning) systems in hospitals, critical manufacturing facilities, clean rooms, and laboratories to help trap foreign metal particles, infectious agents, and a variety of other undesirable contaminants in the environment."
Since the 1970s, exposure to indoor air pollutants has increased dramatically due to a variety of factors, including the products used in the construction and renovation of buildings, the reduction of ventilation to save on energy, the use of more synthetic building materials and furnishings, the use of certain cleaning chemicals and pesticides, and even the personal care items and clothing worn today. Additionally, deferred maintenance on HVAC systems and less frequent building maintenance in general have caused indoor air pollution problems to multiply.
Because of these factors, and the fact that most Americans spend as much as 90 percent of their time indoors, the Environmental Protection Agency now identifies indoor air pollution as one of the top five environmental risks to public health. In fact, studies by the EPA reveal that human exposure to indoor air pollutants may be two to five times higher - and occasionally 100 times higher - than levels of exposure to outdoor air pollutants. This can be especially harmful in educational settings among school-age children as well as in healthcare facilities.
Responding to these health concerns, some vacuum cleaner manufacturers install HEPA air-filtration systems into their vacuum cleaners to better trap and filter indoor pollutants, including dust, mold spores, pet dander, and even odors.
"Another reason HEPA air-filtration systems are being installed in vacuum cleaners is because of the dramatic increase in asthma in the United States," says Hlavin. "We find this a growing problem in schools, offices, and in the hotel industry when rooms are not vacuumed, dusted, or cleaned properly. HEPA filters appear to be able to trap most known asthma triggers, from pollen grains to dust mite fecal pellets and, when used with anti-allergy vacuum bags, other troublesome allergens."
What to Look For
Though HEPA filters offer many health benefits, there are some practical issues that cleaning professionals should be aware of when purchasing a HEPA-filtered vacuum cleaner. HEPA filters can be more expensive than standard vacuum cleaner filters, and this may be reflected in the price of the vacuum cleaner. However, developments in HEPA-filter production and the fact that they are being used in more machines and applications have resulted in some price reductions.
Additionally, because the filter is a finer "mesh" than standard vacuum cleaner filters, there can be a greater resistance to airflow, reducing a vacuum cleaner's suction and performance. There are machines available, however, that do maintain their efficiency levels without sacrificing airflow and suction if used properly and in accordance with manufacturers' maintenance recommendations.
Cleaners must do their homework and evaluate the various HEPA vacuum cleaners available. They should ask distributors questions about the different machines and their performance and should find out if the manufacturers have performed independent studies or test reports to validate the efficiency of their vacuum cleaners and their air-filtration capabilities.
Another good source of information can be the Carpet and Rug Institute, an independent organization that rates vacuum cleaners based on how effectively they remove soil, keep dust in the vacuum cleaner (air-filtration), and maintain the appearance of the carpet itself.
HEPA filters may also need more maintenance and attention than standard vacuum cleaner filters. The filter must be cleaned regularly and, in some cases, replaced more often than standard filters. The frequency depends on how much the machine is used, how well the vacuum cleaner is maintained, and the user's adherence to the manufacturer's recommendations.
Cleaning professionals should also realize that for a vacuum cleaner to provide all of the health and indoor-air-quality benefits a HEPA air-filtration system can offer, the machine must be a true HEPA. This means the HEPA filter is housed in an airtight vacuum cleaner casing to prevent dust and particulates from escaping through gaps in the vacuum cleaner body or around the filter seal, according to Hlavin.
Another factor to consider is the distance that air must travel through the vacuum cleaner. With a traditional upright vacuum, the air flows a relatively short distance from the surface through the machine and into the paper bags.