If you or someone in your family has trouble with allergies or asthma, an air purifier can really help reduce allergens and the symptoms they cause. They can also improve your overall physical and emotional health by providing fresher, less toxic air in your space. Below you will find information about the different types of purifiers and how to choose the right one for you.
Air purifiers that draw air to trap particles are known as “mechanical filter” purifiers. They use at least one of the following filter types:
Sometimes called “panel filters,” flat filters usually contain a fibrous material that can either be dry or coated with a substance like oil to aid in collecting and sticking particles. Flat filters can be composed of wood fill, animal hair, synthetic fibers or even aluminum slits. The low-efficiency furnace filter in many home heating systems is an example of a flat filter, but these typically remove a negligible percentage of smaller-sized particles that can end up in the lungs.
One of the best improvements to the standard flat filter was to increase the density of the material for the filter using smaller fibers and pleated material. Pleating increases the surface area of the filter to help keep airflow through the filter high. Compared to other dry filters, pleated filters have a much higher efficiency.
High Efficiency Particulate Air Filters (HEPA)
More popularly known as HEPA filters, these filters have been traditionally defined as an extended dry-type filter with an efficiency of at least 97.97% for all particles of 0.3-micron diameter. Buyers should be aware of less-efficient products billed as “HEPA-type” filters – their effectiveness at capturing particles and smoke can be as little as 55%.
To qualify as a true HEPA, a filtering system must allow no more than 3 particles out of 10,000 to penetrate the filter. You can find HEPA filters on standard central filtration systems and on HEPA portable units.
The filter of a HEPA air purifier is made of tiny glass fibers that produce a consistency similar to blotter paper. This means that a HEPA purifier is like a tremendous high-pressure system, with air forced through the filtration system under great pressure.
As you can imagine, this makes HEPA filters an expensive proposition in a residence. With powerful fans and engine horsepower, HEPA in a home can be an enormous and consistent drain on electricity.
However, don’t make the mistake of comparing horsepower or wattage of brands to determine performance ratings. When it comes to HEPA effectiveness, look into air displacement effectiveness.
Air displacement describes the amount air moved, measured in cubic feet per minute (CFM). Look for purifiers with high air-displacement HEPA filters for the best recovery of smaller particles such as bacteria, pharmaceutical dust, lead paint or asbestos fibers. A small room purifier may offer as little as 80 CFM displacement, while larger industry models can range on average from 500-80,000 CFM.
Finally, if you want ultimate protection and cost is not an issue, try ULPA (or ultra-HEPA) filters. These are designed to trap 99.999% of all particles that .3 microns or larger in diameter.
Home air ionizers replenish a room’s supply of negative ions, which are essential for clean and pure air. While a home normally possesses less than 100 negative ions per cubic centimeter, health outdoor air has up to 4,000 In fact, the highest levels of negative ions can be found in the pristine areas of the world – such as the Himalayas, the Alps and Antarctica!
Home air ionizers improve air quality by removing dust, odors and other common pollutants. Negative ions generated by the air cleaner literally attach themselves to microscopic particles, which then become too heavy to remain airborne.
Medical experts have long claimed that the process of boosting interior ion supply helps with sleep, depression, allergies, tension, exhaustion and a long list of other ailments.
Air ionizers are becoming increasingly popular in North America, and many homeowners have found that they are affordable, practical and effective in improving air quality. Many of the latest designs are extremely compact, quiet, easy to maintain and contain no filters that require replacement. The only problem is that these particles can accumulate on carpet, walls and furniture meaning that you need to vacuum or clean these surfaces often.
Ozone generator units introduce small quantities of ozone into the air to reduce airborne pollutants. Unlike the filtering systems, ozone generators actively work to “clean” the air.
While there is good evidence that using ozone for water purification methods have helped reduce contaminants without creating negative side effects, introducing ozone into the air of a living space can be a concern.
Some manufacturers use the terms “trivalent oxygen” or “saturated oxygen” as euphemisms for ozone, and it’s important to be aware that some ozone generators are developed for industrial use. For example, ozone generators can be extremely useful in controlling microbes in meat storage.
However, high concentration levels required for contaminant control are in conflict with potential health effects established by authorities such as the National Institute of Occupational Safety and Health (NIOSH), the United States of America’s EPA, and the U.S. Food and Drug Administration (FDA).
Note that the FDA has established that any output of ozone by a device greater than .05 ppm is unsafe to use in any place with human occupancy. Ozone is a potent lung irritant and exposure to elevated levels can be especially dangerous for persons with asthma and other chronic lung diseases.
The Biozone Air Purifiers are the best we have seen for safe air purification and decontamination without the above problems. The have both air and water purifiers.
Choosing an Air Purifier
With all the different types of air cleaners available, how do you decide which one is best for your home? Most air cleaners remove particles, a few remove gases (and odors), and some do both. But that’s where the similarities end!
Your first step is to identify what air quality issues are most prevalent in your home:
Portable vs Central Filtration
Between tabletop and room-model portable units, most people agree that the room models are more effective at cleaning a single room. If you want a larger living space or an entire house cleaned, consider a built-in central filtration system. The smaller portable units cost between $50 and $150, while larger or more efficient portables may cost up to $800. Central air cleaners can cost $1000 to $3000, depending on the size and efficiency of the device.
System efficiency can be measured by the particle size captured. – 0.3 microns or smaller is an excellent “capture” size for any air purifier. Small particles that are inhaled can cause serious health issues, so look for filters or electronic air cleaners that effectively trap both large and small particulates.
Make sure you get a demonstration of any model or system to determine noise levels, even at slow speeds.
Clean Air Delivery Rate
The Clean Air Delivery Rate (CADR) is a standard of measurement that describes the number of cubic feet of clean air per minute an air cleaner can provide. CADR values can range from 30-450 CADR, depending on sizes and models. Many models will express a CADR number for different particulates. For example, a system may cover a room of 70 square feet and report CADR ratings of 45 for dust, 45 for smoke and 60 for pollen.
Reliability and Cost
Check the warranty on any unit you wish to purchase. Compare the product’s lifespan, both for the motor and for the filters or cleaning plates. Look for filters with a long life, and which can be changed manually without requiring a professional.
Our recommendation is to go with the HEPA filters to eliminate larger dust and dander (if you can afford them), with an ozone generator type machine to actually purify the air. We like ionizers as well but they do not actually purify the space, but rather cause the particles to cling to surfaces, meaning you have clean more often.