The US Environmental Protection Agency (EPA) states, “Indoor air pollution is among the top five environmental health risks,” in its publication “Guide to Air Cleaners in the Home”.
People with asthma, lung disease, or allergies are not the only people affected by pollutants. They harm everyone. The most common particles of pollutants are found in residential air mold, dust mites, pet dander, pollen, microplastics, bacteria and viruses. Gaseous pollutants are listed by the EPA as volatile organic compounds (VOCs). They leach from flooring and furniture, chemicals from cleaning agents and pesticides, as well as tobacco smoke when there are smokers in the household. They are even found in air fresheners.
Air pollution inside your home is a serious concern. Maybe a whole-home air purifier is the answer.
We did the research for you and put it all here. Read on to find out what they are, different residential air purifier types, pros and cons, whether they are worth the money, and what else you can do to purify the air in your home.
Air purifiers are also called air cleaners. Their purpose is removing pollutants and allergens from the air in your home using filters.
The major upside to media-type air purifiers is that they remove more than 99.9% of pollutants and allergens from the air - as they are designed to do. Also, the air purifier itself, the replacement filters, and installation are all affordable.
Air cleaners only remove air pollution when your blower fan is running. Depending on where you live, there may be a few months out of the year when you don’t really use your HVAC system. However, most systems will still allow you to turn the fan on, even if it’s not heating or cooling your home. This will produce electricity cost, but it is less than a stand-alone air purifier when considering the entire year’s utility costs.
They can only remove pollutants that pass through them. If your flooring or furniture is emitting VOCs, you will still breathe them until they can be filtered through the purifier. If there is a smoker in the home, secondhand smoke will still be an issue until it can be filtered. If no fresh air gets into your home, the air will quickly become polluted.
Media filters must be regularly replaced to maintain efficiency. If they are not replaced, they will become blocked, and the electrostatic filters will eventually lose their charge.
The filters can be so thick that they make it hard for furnaces and air handlers to pull air through them. The result of this is a system that works harder, using more energy and making itself prone to mechanical failure down the road.
According to HVAC expert Jeanie Wong, photocatalysis is “the oxidation of organic contaminants such as bacteria and mold using magnetic particles coated with titanium dioxide nanoparticles”, producing harmless substances like carbon dioxide and water. A PCO filter comes coated with titanium dioxide that comes in contact with harmful pollutants. A UV light is then shined onto the catalytic filter to create a reaction that destroys the pollutants. This technology is often used in combination air cleaners.
On the upside, this technology has been proven effective, often used in health settings and food processing for air cleaning. A PCO combination, or hybrid, air cleaner is the most effective option out there. It does not hinder airflow, so your system won’t work much harder. One downside is the higher cost of the air cleaner, and the electricity cost to run it.
A typical EAC includes two types of filtration. A pre-filter catches the large particles, then the tiny particles are charged with electricity. The charge attracts them to collector plates with an opposite charge, much like a magnet. This removes them from the air. In some cases, the electrical charge can even destroy the virus or bacteria.
These units are sometimes called ionic and electrostatic air cleaners because of the electrical charge they use. They can be cleaned in a dishwasher as needed, but should be thoroughly air dried.
These filters are washable. This is a plus, because replacement cost is low - they last a year, or longer! This also reduces waste in landfills.
The downside is the hassle of washing the filter regularly - typically every few weeks to a month. The collector plates in the purifier must be washed regularly as well, or they won’t attract the charged particles. At this point, the purifier is no longer doing its job.
EACs only trap 95%-97% of the particles flowing through them. Just like the mechanical air purifiers, electronic models will only filter the air when your system is running.
EACs also have parts that can fail, and would require replacement. A media air cleaner does not.
The major downside to EACs is that they emit ozone.
The extra oxygen molecule in ozone can combine with organic cells in your body, and alter them negatively. The EPA warns that “relatively low amounts can cause chest pain, coughing, shortness of breath, and throat irritation. Ozone may worsen chronic respiratory diseases such as asthma and compromise the ability of the body to fight respiratory infections.”
Due to the risks, we often recommend avoiding ozone-producing air purifiers. If the manufacturer cannot positively confirm that no ozone is emitted, avoid that model - the risk outweighs the advantage!
Where odors are an issue, your best option is choosing an air purifier - either electronic or media-only - that uses carbon or charcoal rather than ozone to remove the odors.
Some air cleaners combine what was discussed above - media filters, electronic charging, and UV light. The cost will go up for these units, however they will remove both small and large particles, plus odors.
You may be thinking that since your system already has an air filter in the furnace, why is another filter needed?
The short answer is, it may not be.
If you aren’t experiencing breathing problems or allergen problems, adding more equipment to your system likely isn’t a cost-effective way to combat indoor air pollution. We listed some recommendations below to improve indoor air quality in any home.
However, if you are experiencing breathing problems, a central air purifier could be part of a broader solution to your problem.
Clean indoor air is accomplished through many different practices. Installing the air cleaner could be one of them.
Other tips include: