When it comes to keeping your home clean and healthy, air filters are an essential part of the equation. But with so many different types of air filters available, it can be difficult to know which one is right for you. In this article, we'll discuss the different types of air filters, their nominal sizes, MERV ratings, and other important factors to consider when choosing the best air filter for your home. The first step in choosing an air filter is understanding the nominal size.
This is the size of the filter that is typically listed on the packaging. It is usually expressed in three specific dimensions: length, width, and depth. For example, a 20x25x4 air filter would be 20 inches long, 25 inches wide, and 4 inches deep.
Types of Air FiltersOnce you know the nominal size of the air filter you need, you can start looking at the different types available.
The most common types are fiberglass filters, HEPA filters, electrostatic filters, and washable/reusable filters. Fiberglass filters are the most basic type of air filter and are usually the least expensive option. They are made from spun glass fibers and are designed to trap large particles like dirt, pollen, hair, and dead skin cells. However, they are not very effective at trapping smaller particles like pet dander, dust mites, mite feces, and other microbiological contaminants.
HEPA (High Efficiency Particulate Air) filters are designed to trap even smaller particles than fiberglass filters. They are made from a combination of synthetic fibers and paper and can trap particles as small as 0.3 microns in size. This makes them ideal for trapping tobacco smoke, airborne particles, mold spores, and other pollutants. Electrostatic filters use an electrostatic charge to attract and trap particles in the air.
They are usually made from polyester or washable aluminum screens and can be used in both residential and commercial/industrial HVAC systems. They are also more sustainable and cost-effective than disposable filters since they can be washed and reused multiple times. Washable/reusable filters are similar to electrostatic filters but are usually made from pleated or pleatless materials like polyester or foam. They are also more sustainable than disposable filters since they can be washed and reused multiple times. However, they may not be as effective at trapping smaller particles like dust mites or mold spores.
MERV RatingsWhen shopping for an air filter, you may also come across something called a MERV rating.
This stands for Minimum Efficiency Reporting Value and is a measure of how effective an air filter is at trapping particles in the air. The higher the MERV rating, the more effective the filter will be at trapping smaller particles like dust mites or mold spores. The most common MERV ratings range from 1 (0.75 microns) to 16 (0.3 microns). A MERV 8 filter is typically used in residential HVAC systems while a MERV 13 filter is usually used in commercial or industrial HVAC systems. Higher MERV ratings may also be available but these are usually only used in specialized applications.
Other Factors to ConsiderWhen choosing an air filter for your home or business, there are a few other factors to consider besides size and type.
For example, some air filters come with additional features like activated carbon or UV filters that can help improve indoor air quality by trapping odors or killing bacteria and viruses. You should also consider how often you need to replace your air filter. Disposable fiberglass or HEPA filters should be replaced every three months while washable/reusable filters may last up to a year before needing to be replaced. Finally, you should consider how much energy your HVAC system uses when running with different types of air filters. Higher-efficiency filters like HEPA or electrostatic air filters may require more horsepower from your HVAC unit but can also help reduce energy costs by reducing pressure drop across the system.