What to Look For in a Whole House Air Purifier
All about home air purifiers, indoor air pollution, and what air purifier is best for you, your family, and your home.
The Environmental Protection Agency (EPA) states that indoor air pollution is among our top five environmental health risks. And while ventilating with clean outdoor air is a solution, it’s not always practical. Weather conditions and outdoor air pollution often make it difficult or impossible. That’s why a home air purifier is important.
The EPA goes on to say that air cleaning devices may be the answer. But if you’ve done any research online, you’ve discovered many different kinds of air purifiers. You’ll see terms such as “HEPA,” “activated oxygen,” “air filtration,” and “ionic comfort.” Many of these are portable air purifiers. A whole home air purifier or whole home air purifier is contractor installed in the HVAC system of a home to clean home air. Some whole home air purifier work along with cleaners, filters, and the HVAC’s fan.
If you’re confused about air purification products and a home air purifier, you’re not alone. So what’s best for you and your family?
Consider the Indoor Air Pollutants in Your House
A good place to start is to evaluate what indoor air pollutants may be in your house. The EPA divides them into two categories: particulate matter and gaseous pollutants.
Particulate matter may come from organisms such as dust mites, molds, bacteria, and viruses. It can be dust, smoke, animal dander, or particles from combustion in the home such as stoves and fireplaces.
Gaseous pollutants originate with combustion and from materials found in and around the house. Stoves, vehicle exhaust, tobacco smoke, and wood smoke produce gaseous pollution.
Household products also release gasses, called volatile organic compounds (VOCs) into the home. This “off-gassing” can originate in building materials such as particle board and home furnishings. Off-gassing also occurs when you use paint, varnishes, or common household cleaning products.
What Air Purifier is Best for You?
Every home is different and the weather, pollen count, and outdoor air is unique to each region of the country. Plus, the people living in your home may have special medical conditions such as asthma. If they’re young children or seniors, they will also be more vulnerable to indoor air pollution.
Some air purifier systems and portables are designed to remove certain types of pollutants from your air. Other air purifiers work to destroy the pollutants.
There are really two types of air purifiers: a whole house air purifier and portable air purifiers. Whole house air purification systems take care of the entire home from kitchen and bathrooms to bedrooms and living areas. A portable air purifier works best in single rooms. Portable air purifiers are extra protection in an infant’s or child’s bedroom or the bedroom of an elderly parent or a family member with asthma or allergy sensitivity.
Here’s more on how different air purifiers work to control indoor air pollution…
Air Purifiers That Remove Particles
To rid the air of polluting particles, purifiers use either mechanical air filters or electronic air cleaners.
- Mechanical filters capture particles on the materials in the filter. HEPA, or High Efficiency Particulate Air filters are mechanical air filters.
- Electronic air cleaners use electrostatic attraction to trap particles. These cleaners draw air through an ionization section that electrically charges the particles. The charged particles accumulate on a series of oppositely charged plates called a collector. Ion generators, also called ionizers, don’t use a collector but disperse the charged ions into the air. There they attach to other airborne particles so they’ll adhere to walls and furniture, or attach to one another and thus settle faster.
Air Purifiers That Remove Gasses (VOCs)
A sorbent such as activated carbon is used in gas-phase air filters to adsorb gasses and odors. This removes them from the air. Adsorption is the adhesion of atoms, ions, or molecules from a gas to a surface, in this case the filter.
The thing to look out for in gas phase filtration systems is that they usually work on only one or a limited number of gaseous pollutants. They will not work on gasses that they were not designed for. And none remove all the gaseous pollutants in a typical home’s air. For example, carbon monoxide is one gas that is dangerous but not easily captured by today’s air purifiers.
Air Purifiers That Destroy Indoor Particles and Gasses
Air cleaners that use ultraviolet light (UV) to destroy indoor air pollutants are called ultraviolet germicidal irradiation (UVGI) cleaners and photocatalytic oxidation (PCO) cleaners. Some manufacturers also sell air cleaners that produce ozone to destroy pollutants. But, as you will see, that is not a recommended option, as ozone is a known lung irritant.
- Ultraviolet Germicidal Irradiation (UVGI) kills biological pollutants using short-wavelength ultraviolet light. These UV lamps destroy viruses, bacteria, allergens, and molds in the air or growing within HVAC systems. UVGI systems are typically used in hospitals to kill airborne pathogens, preventing the spread of disease.
- Photocatalytic Oxidation (PCO) incorporate photon and UV energy to activate a catalyst that destroys gasses (VOCs). In simpler terms, light energy quick-starts the process of turning pollution causing molecules into more harmless substances.
- Ozone Generators use UV light or an electrical discharge to produce ozone. Supposedly, the ozone destroys pollutants, but this is disputed by scientists and the EPA. They are often sold as providing “activated oxygen,” “super oxygen,” “trivalent oxygen,” “allotropic oxygen,” or “saturated oxygen” when they are talking about ozone.
The EPA and other government agencies have determined that ozone generators are not safe and they do not effectively eliminate indoor air pollutants. When you shop for air purification in your home, the best advice is to stay away from any system using ozone generation. According to the EPA, “At concentrations that do not exceed public health standards, ozone has little effect in removing most indoor air contaminants. Thus, ozone generators are not always safe and effective in controlling indoor air pollutants.”
Measuring Performance of an Air Purifier
There are two kinds of air cleaning devices you can buy. You can get a whole house air purification system installed in the ductwork of your HVAC system. Or you can buy a portable air cleaner for one room only or if you do not have a forced air heating/cooling system.
Evaluating Filters in Your HVAC with the MERV Rating
The quality of filters installed in your ductwork are measured in terms of their efficiency in removing airborne particles from the air that passes through them. The measurement is called the minimum efficiency reporting value, or MERV. The ratings range from a low of 1 to a high of 20.
What MERV Rating Should You Look For?
- Filters with a MERV of 1-4 are generally not meant for controlling indoor air quality, but to protect the HVAC equipment.
- A MERV rating of 5 to 13 is reasonably efficient at removing particles from the air, according to the EPA.
- A MERV of 7-13 can be almost as effective as HEPA filters. HEPA stands for high-efficiency particulate air. To qualify for a HEPA rating the filter must meet certain government standards. The nice thing about MERV filters of 7-13 is that they are usually less expensive than HEPA filters. Plus, they’re quieter since they have less air-flow resistance. MERV 11 air filters are a good choice to clean indoor air as they create minimal backpressure–so your equipment does not have to work harder–and a MERV 11 traps a lot of particles and typically does not need to be replaced for up to one year, depending on where the home is located.
- Higher efficiency filters of over MERV 13 are generally not installed in residential HVAC systems. They are more commercial grade for hospitals and require special installation. If you are thinking of purchasing a higher efficiency filter, be sure to consult with your heating/cooling professional. Some residential HVAC systems may not be able to accommodate them because of insufficient fan or motor capacity.
Evaluating a Portable Air Purifier
Portable air purifiers are measured by their clean air delivery rate, or CADR. The Association of Home Appliance Manufacturers developed this measure of a portable’s delivery of contaminant-free air in cubic feet per minute. So, let’s say an air cleaner has a CADR of 150 for dust particles. That means it reduces dust particles in a room to similar levels if you were to add 150 cubic feet of clean air per minute. The higher the CADR, the better the filtration.
An ionic air purifier gives airborne germs and particles a static charge so they stick to the walls, ceilings, floors and furniture in the room as well as you. Ionic air purifiers do not get rid of particles, they pile them up in the home.
An ozone purifier creates harmful ozone and should be avoided. In fact the state of California has banned certain ozone producing air purifiers since they are harmful.
We Can Help You Keep Your Indoor Air Quality Fresh, Clean, & Pure
We hope that you now feel more comfortable in your search for solutions to indoor air pollution. Below you’ll find links to more information on indoor air quality, asthma and allergies, and common household products that emit pollutants into your house.
Also, Field Controls offers custom HVAC air purification solutions that meet the highest standards for indoor air quality. Our Healthy Home System is a whole house air purification system that combines air purification, air filtration, and a reliable source of fresh air to keep your home healthy.
Our Healthy Home Trio Portable is ideal for homes without forced air ductwork and for extra protection in any room. This portable air purification includes multi-stage filtration and PRO-Cell Technology odor and VOC reduction.
Since 1927, we have been a leader in the development and manufacture of products that control, move, and improve air. We look forward to helping you keep your indoor air fresh, clean, and pure.
Environmental Protection Agency (EPA), www.epa.gov/ and https://www.epa.gov/indoor-air-quality-iaq/guide-air-cleaners-home
Ready to Call a Contractor?
Use our locator tool to find one of our over 1,000 Field Controls trained contractors. Find a Nearby Dealer >
Shop Replacement Filters & UV Lamps
Field Controls sells replacement filters for all major brands of media air cleaners.
Whole House Protection
In-duct UV-Aire, Duo, and TrioMAC air purifiers use ultraviolet lamps to continuously attack airborne mold, bacteria, and viruses as they circulate through your home’s duct work.
Learn More >