Indoor air can contain pollutants that could cause health problems. These pollutants can be found in both indoor and outdoor environments. Indoor air pollutants include gases and particles, as well as volatile organic compounds (VOCs). Particulate matter, including PM 2.5 [fine] or PM 10 [coarse], as well as formaldehyde and mold, are common indoor contaminants. Indoor air quality can vary greatly from one home to another and within the same day. Most people spend 90% of their time indoors. This means that most of their exposure to airborne pollutants occurs in their home.
You can improve indoor air quality by removing pollutants from the air and allowing fresh air to circulate. Research has shown that filtration can also be used as an adjunct to ventilation and source control. You can improve indoor air quality by using a portable cleaner or upgrading your central heating, ventilation, and air-conditioning system (HVAC). Air purifiers and air sanitizers are portable air cleaners that filter air in one room. The central furnace and HVAC filters are designed for air filtration throughout a house. Although portable air cleaners and HVAC filters are effective in reducing indoor air pollution, they can’t remove all pollutants.
Tips For Selecting a Portable Air Cleaner
Keep these things in mind when choosing a portable air cleaner:
There are no filters or air cleaners that can eliminate all the pollutants in your home. Most filters can filter both gases and particles. Many air cleaners have two filters. One for gases and one for particles. Some even include odor-causing gases. Some air cleaners have only one filter, which is usually for particles. Some filters or air cleaners are designed to target specific gases or VOCs. For more information, consult the labeling or packaging of each product.
Regular replacement is necessary for all filters. Filters that are dirty or overloaded will not work properly.
PORTABLE AIR CLEANERS
When considering filtering particles, choose an air cleaner with a clean air delivery (CADR), that is big enough to filter particles. Higher CADRs mean cleaners can filter more particles and can cover a larger area. The largest area an air cleaner can clean is the one that has the highest CADR.
When considering filtering gases, choose a portable cleaner that has an activated carbon filter, or another filter designed to remove gases.
It is important to note that there are not many widely-used performance rating systems for [portable air cleaners and filters that remove gases. The CADR rating system only applies to particles. Activated carbon filters are effective if there is enough material in the filter.
An activated carbon filter and a high CADR portable air cleaner can filter both gases and particles.
In general, a cleaner that is run at a slower speed will filter more air. Higher fan speeds will allow more air to pass through the filter, which will result in a higher filtration rate. Air filtration can also be increased by increasing the time that an air cleaner runs.
| Portable Air Cleaner Sizing for Particle Removal | ||||||
| Room area (square feet) | 100 | 200 | 300 | 400 | 500 | 600 |
| Minimum CADR (cfm) | 65 | 130 | 195 | 260 | 325 | 390 |
Note this chart is for estimation purposes. The CADRs are calculated based on an 8-foot ceiling. If you have higher ceilings, you may want to select a portable air cleaner with a higher CADR.
Q&A: Air Filtration and Air Cleaning
Can portable air cleaners or furnace/HVAC filter filters be used indoors to improve indoor air quality?
Yes. Most portable air cleaners as well as furnace/HVAC filters are capable of filtering particles from the air. Some filters can filter small particles that pose the greatest risk to your health (PM 2.5). Air cleaners and filters can also filter gases. The cleaner will filter more air the longer it runs. It is important to remove indoor air pollutants from the air cleaner and to vent with fresh outdoor air. The need to ventilate and control pollutant is not replaced by filtration.
Are portable air cleaners or furnace/HVAC filters able to have a positive effect on your health?
Possibly. Many studies that used portable HEPA air cleaners showed small improvements in respiratory and cardiovascular health. Although the improvements are not often noticeable, they can be measured by professionals.
See the following publications for more information about particles and health
EPA Indoor Particulate Matter: www.epa.gov/indoor-air-quality-iaq/indoor-particulate-matter
EPA Particle Pollution and Your Health: www3.epa.gov/airnow/particle/pm-color.pdf
Are portable air cleaners or furnace/HVAC filters able to reduce asthma or allergy symptoms?
Possibly. Numerous studies using portable HEPA air filters have shown improvements in some or all of the symptoms. These studies don’t always show significant improvements and do not include all symptoms.
Are portable air cleaners and furnace/HVAC filter able to solve mold problems?
No. Both furnace/HVAC and portable air cleaners do not treat the root cause of mold or musty odors. Mold can be caused by water or moisture problems in the building. Mold problems can be solved by removing the source of moisture and cleaning up the mold. Some mold particles can be removed by portable air cleaners or furnace/HVAC filter. They may reduce odors in some cases but will not solve a mold or moisture problem.
Note, the EPA suggests that you NOT use portable air cleaners that deliberately produce ozone. Ozone can cause lung irritations. Ozone can be emitted from some air cleaners, especially plasma air cleaners, UV lights without proper lamp coatings, and ionizers. The California Air Resources Board as well as the Association of Home Appliance Manufacturers keep lists of air cleaners that have been tested for ozone emissions.
Free video about air purifiers
Q&A: Portable Air Cleaners
A majority of portable air cleaners come with a CADR rating. What does this mean?
The clean air delivery rate (CADR) is the most important metric for portable air cleaners. This rating is used to help consumers choose the right air cleaner for them based on how large the area they will use. The larger the CADR, the larger the area it can handle and the more airborne particles it will remove. This rating is usually measured at the highest speed of an air cleaner.
How can I choose an air cleaner that will effectively remove small particles of greatest concern (PM 2.5)?
The CADRs of air cleaner packaging for specific pollutants will be indicated – packaging will mention pollutants such as pollen, tobacco smoke, and dust. These pollutants can be used to illustrate small, medium, and large-sized particles. A portable air cleaner with a high CADR (for tobacco smoke) will remove the smallest particles. You should make sure that the CADR is large enough to cover the area or room you intend to use it in.
How can I determine the area or size of a room to choose the best air cleaner?
Multiply the area you want to use the air cleaner by the length and width. This will give you the area or room size in square feet. This is the recommended maximum room size for the product packaging. If your floor plan is open, consider how much space the cleaner will take up. You should choose an air cleaner that can handle a greater area if you have tall ceilings (above 8 ft). Multiple air cleaners may be necessary if you have a larger area than the product can handle.
How can I select an air cleaner that removes volatile organic compounds (VOCs).
You should choose an air cleaner that has an activated carbon filter, or another absorbent filter to remove gases. These filters can work well if there is a lot of material in the filter. (In other words, the thicker the filter, the better.) Other technologies, such as photocatalytic oxygen, plasma or ultraviolet (UV), have not been proven to remove gases in portable residential air cleaners.
Are portable air cleaners rated for noise?
Some portable air cleaners have noise ratings. This rating might be printed on product packaging. The fan speed setting is a major factor in noise levels. An air cleaner with a low noise rating might be a good option if noise is a problem. A noise rating of 50 decibels (dB), is approximately the same operating noise as a modern refrigerator.
In which room of your home should you put a portable air cleaner?
Place the unit in the area you spend most time in. While many units can be placed on the ground, some are better suited for placement on tabletops. Airflow must be free from obstructions, regardless of whether the unit is placed on the floor or on a tabletop. Air cleaners should be kept away from curtains and other obstructions that could block the airflow. If you feel uncomfortable due to a draft from the air cleaner, redirect the airflow away.
What does this mean if a portable air cleaner has the EPA’s ENERGY STAR label?
Some portable air cleaners on the consumer market have been certified ENERGY STAR. The ENERGY STAR mark means it meets the strict energy efficiency guidelines of the EPA. This label does not indicate its air-cleaning efficiency.
A good option for you may be ActivePure – request more information here.