Tips on what to look for when shopping for an air filter for your home. Learning what the different technologies do and what allergens they remove makes the decision easier.
How do air purifiers and filters work?
High Efficiency Particulate Air (HEPA) filters are the easiest air filters and to find, and are useful against a wide range of allergens, including dust, pollen, mold, and pet products. These filters are not effective against odors, such as smoke, nor do they destroy viruses or bacteria. If you purchase this type of air filter, be sure to buy one that traps 99.97% of airborne particles, as small as .3 microns in size.
Ionizers use negative ions to remove particles down to .1 microns in size from the air. This gives them a broader range than HEPA filters, and allows them to remove more particles. They do not always trap what they remove, however, and work best in combination with other types of filters.
Carbon filters are included in some air filtration devices, and are effective against most odors. Some filters contain a mixture of carbon and zeolite, which is less expensive than carbon but not as effective.
Some are purifiers use ozone to neutralize strong odors. It's effective, but ozone has its own odor that some people are sensitive to. If you choose this type of air purifier, be sure that you can turn off the ozone producing function.
Germicidal ultraviolet lamps are included in many high-end air cleaning units, and are effective against a host of airborne pollutants, including bacteria, viruses, and mold. These lamps do not remove particles from the air, but they kill airborne germs. When placed behind a HEPA filter, they can reduce contamination that can be caused by dirty filters.
Because most people want to remove all of the harmful particles and bad smells from the air in their homes, it usually makes sense to buy an air cleaner that combines several technologies. No single type of air filter or purifier is perfect, but a carefully selected combination can be quite effective.
What factors affect true cost?
Because many air cleaners require frequent replacement of filters, or run on electricity, the true cost of an air purifier or filter can be surprisingly high. Before you choose a machine, check to see how often filters need to be replaced, and how much those filters cost. Inexpensive machines sometimes require expensive filters that can only be purchased from the manufacturer.
Electricity can be a major cost of cleaning the air in your home. Duct-based whole home systems can use nearly a dollar's worth of electricity per day. That may be a price you're not willing to pay, so check the wattage of the system you're considering.
Other factors to consider
One of the biggest complaints people have about air filters and purifiers is the noise of the fans. Systems that clean the air in large rooms need large fans, and can be very loud. Many companies offer free trials of their products, which is a good way to bring a system into your house to make sure it's not too loud. If you only keep it on when nobody is home, your filter or purifier won't be able to work as well.
Think about whether you want to clean the air in one room, several rooms, or an entire house. It is often most effective to have portable units in each room, but filter costs can be prohibitive. Duct-based systems that turn your heating and cooling system into a giant air cleaner can be effective, but to get the maximum benefit you'll need to keep the fan on at all times.
If you suffer from allergies, an air filtration or purifying system can be a worthy investment. If you choose a system proven to remove the substances that cause your allergies, think about the true costs, and plan accordingly, you will find yourself breathing better, with fewer headaches and other allergy-related problems.
