Pollen, dust, and other particles that can aggravate the lungs and sinuses float in the air and remain there until they are trapped by an air filter. In fact, choosing the right one could improve your health and prevent bacteria and viruses from circulating in your home or office space.
How Air Conditioner Systems Work
You don’t need a degree in physics in order to understand how air conditioners work, but it is a very technical process. Hot air and cold air behave differently. You know this from changes in weather that are caused by hot air and cold air coming together and creating tornadoes or hurricanes. By studying the dynamic properties of air, physicists, engineers, and inventors have been able to build units that manipulate air to make more comfortable airflow where you want it.
Most homeowners have a big gray box outside of their home that contains all of the mechanisms to cool a home: the fan, compressor, and condenser. A refrigerant cools the coils in your air conditioning system and a fan blows air across those coils. Now, the temperature of the air changes the way it acts. Temperature also affects its pressure, which you probably know from listening to weather reports. When the refrigerant is compressed and then sent to the condenser, heat is transferred out of your house. Cool air is distributed throughout your home via air ducts.
Now that you have this cool air that has circulated in your home, it’s time for it to go into a return duct where it is passed through your air filter. This is where that air gets cleaned out, and whatever is in the atmosphere gets removed. But if it is still warmer outside than it is inside then you are going to lose some of that cool air, so the whole process has to keep repeating itself the temperature set by the thermostat is reached.
What Air Filters Do
Your filter is one of the main lines of defense against any allergens entering your home as it is coming in from outside. But filters also work when room temperature air is pulled in through return ducts and passes through the filter to remove dirt, dust, and other particulates. After the cool air is generated by your AC unit, it is distributed throughout your home and picks up particulates from hair sprays, cooking fumes, smoking, using nail polish or other paints, or burning candles. You can tell which vents in your home are return vents by placing your hand in front of them and feeling them pull (return vent) or push (supply vent) air out.
How Filter Performance Is Rated
Not all people are the same, not all lifestyles are the same, and not all air filters are the same. The performance of air filters is rated by measured by a Minimum Efficiency Reporting Value also known as a MERV rating. This measurement scale was developed in 1987 by the American Society of Heating, Refrigerating and Air Conditioning Engineers to report the effectiveness of air filters. Disposable fiberglass or synthetic panel filters provide the least amount of filtration and are often used in residential settings. A filter with a MERV rating of four can filter out pollen dust mites, spray paint dust, and textile fibers, but a filter with a MERV rating of one can only filter out particles as small as carpet fibers.
Going up the scale, filters with a MERV rating between five and eight tend to be pleated or cartridge filters. Pleated filters can be disposable and have an extended surface area made with a cotton-polyester blend media in a cardboard frame. Filters with a MERV rating of eight can filter mold spores, hairspray, fabric protector, and cement dust. These are higher-quality residential filters than those with a lower rating and are suitable to use in commercial buildings.
Residential and commercial building property managers can opt to use superior filters that are as effective as the filters used in hospital laboratories. These are filters with a MERV rating between nine and 12 and are made out of microphone fiberglass or synthetic media. They are typically 12 to 36 inches deep with 6 to 12 pockets. They can filter out Legionella, milled flour, auto emissions and welding fumes.
Commercial filters can collect bacteria, smoke, and sneezes, and are generally between a MERV rating of 14 and 16. Filters with a MERV rating of 17 or higher, which can filter out viruses, are typically found in hospitals, I can go up to a MERV rating of 20.
Replacing Your Filter To Maintain Air Quality
Over time that filter is going to become saturated with particles that it has collected if it is not cleaned. But how long do you have before that happens? The answer is going to depend on what type of filter you use, your health, and your home life. A young couple with no pets in an apartment may change their filters less often than their neighbor who smokes in their flat, or a family of five with two children with allergies and another with asthma that insisted that the family buy a dog. Each of these residents has different lifestyles, different types of families, and different habits that affect the quality of air. But no matter what your home situation is like, there is an air filter and schedule that keeps you healthy and is suitable for your unit.
In order to control dust in your home, it’s important to not just buy the filter with the correct MERV rating for your unit and needs. You also need to change it regularly. Depending on your lifestyle and needs you will need to change your air filter once every one to six months. To speak with an air filter specialist who can advise you on which type you need for your unit and based on other factors in your home whether you have pets or asthma, click here.