How to Choose an Air Purifier
This list is intended to help you determine how to choose an air purifier to suit your needs. A number of factors should be considered to find the best unit, including:
- Price
- Reliability
- Efficiency
- Noise level
- Clean air delivery rate (CADR)
- Portable filtration v. Central filtration preference
Portable Filtration vs. Central Filtration
Whether you choose to purchase a portable unit or a filtration system linked to your central air may depend on needs and budget. Portable air filters are better for those with a tight budget who want the flexibility to move the unit from place to place. Portable filtration, unlike central filtration, is usually only capable of filtering the air in one room. Of all the available portable devices consumers generally agree that room-model portable units more effectively filter particulates and gases than tabletop portable units.
Prices for smaller portable units range between $50 and $150 while larger, higher efficiency portables come with a hefty price tag (costing as much as $800). Central air filtration systems start at $1,000 and reach up to $3,000. Central air device price is dependent upon unit efficiency, technologies and size (both device size and the air capacity the device is purported to filter).
Clean Air Delivery Rate
This rate, also called CADR, is accessed for each air filtration unit to tell the consumer how many cubic feet of clean air per minute the air purifier can provide. The CADR is a standard form of measurement all manufacturers use and as such is a good basis of comparison to determine the work load a unit can handle. Some units can filter 30 cubic feet per minute while others can provide fresh air to 450 cubic feet every minute. In addition, researchers often determine the unit’s capabilities and CADR regarding different gases and particulates. As an example, someone with a pollen allergy may be interested in a system which has a CADR of 60 for pollen, a CADR of 45 for dust, and a CADR of 45 for smoke.
Noise Level
Before purchasing, ask for a demonstration of the model. Pay attention to the noise level produced at both slow and high speeds.
Efficiency
Efficiency is determined based on the particle size the filters can capture. Higher efficiency devices capture some of the smallest particulates and gases. A good "capture" size for an air filter is 0.3 microns or smaller. Look for an air purifier that can filter and trap small and large particles. Inhalation of large numbers of particulates and gases can cause illness and long term health issues.
Reliability
The following should help you choose a reliable product:
- Review the warranty thoroughly as it should attest to product reliability.
- Discover which units have filters with the most longevity.
- Look for a unit with filters that are easily interchanged.
- If a unit requires professional service for every filter
change it will be more costly.
- Compare the projected lifespan of all aspects of the unit including:
- The motor
- The filters
- The cleaning plates