What is in an Air Filter and How to Manage Allergies and Asthma

Learn about different types of air filters available for HVAC systems & their benefits for allergy & asthma management. Understand how electrostatic & media filters work & how washable & disposable options can help save money.

What is in an Air Filter and How to Manage Allergies and Asthma

An air cleaner is a device that removes solid particles from the air, such as dust, pollen, mold, fibers, germs, etc. It is generally made of a spun glass fiber material or of pleated paper or cloth enclosed in a cardboard frame. Its basic function is to clean the air circulating in the heating and cooling system. People living with allergies or other respiratory problems may benefit most from HEPA filters.

A contractor needs to adjust these filters to fit your specific HVAC system. Using small cotton and paper fibers, electrostatic filters create static electricity that acts as a magnet for dust and other particles in the air. The magnetism is strong enough to prevent these particles from spreading throughout the house, making them one of the best options for those who need a filter that can combat allergens. An additional advantage for electrostatic filters is that they are available both disposable and reusable. When it's time to change the filters, you can decide whether to wash and reuse them or throw them away and buy new ones. While certain types of air filters come with reusable and disposable options, washable filters are an eco-friendly way to save money.

The starting price of this type of air filter for HVAC systems is high, but it should be considered as an investment that will last for many years. The starting price is likely all you'll have to pay, as you can simply wash and reuse the filter over and over again instead of buying a new one every few months. Washable filters need to be maintained well to ensure they work as they should. As one of the main types of air filters, they come with maintenance instructions that must be followed. It is very important to ensure that the filter is completely dry before reattaching it.

Even the slightest amount of moisture that remains can cause mold and mildew to form on the filter and expel them into the air you breathe. When it comes to air filters for HVAC systems, media filters can provide more benefits than standard filters with high MERV ratings. Media filters provide the same level of filtration as a high MERV filter, but do so without the negative consequences of airflow or static pressure. In contrast, media filters have a larger surface area, which successfully avoids significant static pressure and provides better filtration. Media filters are very easy to maintain and ideal for filtering bacteria and other small airborne contaminants.

Filtered dirt seals in the filter, preventing it from being ejected back into your home. Media filters are also robust and cost-effective, so they need to be changed as infrequently as once or twice a year. Much of this has to do with the fact that the largest allergen particles are deposited on carpets, surfaces and bedding instead of circulating in the air. Evidence indicates that combining medium to high efficiency air filters with a portable air purifier used in the bedroom, along with a regular cleaning routine, are the best ways to manage asthma and allergy symptoms. These filters aren't known for improving air quality, as they can't put much effort into it and can only trap some of the dust and allergens. The downside to these filters is that they require your HVAC system to work a little harder to draw air through the unit, which can cause your HVAC system to lose efficiency sooner than expected. The opposite is true if you don't have an air filter or if the air filter is so dirty that it restricts airflow. Another method, air ionizers, use fibers or elements with static electrical charge, which attract dust particles.

Internal combustion engine air intakes and air compressors tend to use paper, foam, or cotton filters. Oiled cotton gauze is used in a growing number of aftermarket automotive air filters that are marketed as high-performance items. In the early 20th century (around 1900 to 1930), water bath air filters were used in some applications (cars, trucks, tractors, and portable and stationary engines). For this reason, these filters are not recommended for people who have respiratory problems and need a filter that improves indoor air quality. The following publications provide information on portable air filters and heating and air conditioning filters that are commonly used in homes. These air filters provide an additional passage “in addition to regular filtration”, cleaning the air even more.

The cabin air filter is usually a pleated paper filter that is placed in the outside air intake of the vehicle's passenger compartment. If you have a house with several residents who could have respiratory problems due to a dirty air filter, buying a filter every few months may be cheaper than having several people who need to see a doctor at once. Many experts recommend a combination of methods to manage allergies and asthma, including a cleaning routine, mechanical filters, and portable air purifiers.

Cleveland Spadafore
Cleveland Spadafore

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