Any home with a central heating and cooling system requires air filters. While these are often out of sight and out of mind, they are critical to air quality.
The type of filter you need depends on what contaminants you want to remove. This article will explore different types of air filters based on their MERV ratings and how they capture pollutants.
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Medium-efficiency filters
Unlike low-efficiency filters typically used to protect the HVAC system alone, medium-efficiency air filters do a good job removing nuisance pollutants from the indoor environment. Often, these include coarse dust, cat dander, tobacco smoke, viruses, and odors.
They’re also great prefilters for high-efficiency filters to reduce their heavy workload and extend their life. They have a low resistance and large windward surface area to capture airborne particles of diameters between 3 and 10 microns.
Its arrestance or particle counting concentration usually expresses the efficiency of a filter. Filter penetration and decontamination efficiency are important measures of a filter’s performance. A filter’s performance is influenced by its construction, design, and materials. Its performance is rated by the Minimum Efficiency Reporting Value (MERV). The MERV rating is determined by measuring a filter’s removal efficiency in three micro-meter ranges (0.3 to 1 micron, 1 to 3 micron and 3 to 10 microns). The higher the MERV rating, the better the filter.
High-efficiency filters
These filters from air filter supplier Richmond, are designed for high-technology industries like electronics, integrated circuit fabrication and nuclear power plants, use electrostatically charged elements to capture tiny particles. They are rated using the FPR (filter performance rating), which uses a number scale and color-coding system to indicate filter strength and which contaminants it is best suited to catch.
High-efficiency filters are more expensive than low-efficiency filters, but they provide better filtration that reduces energy costs while providing healthier and more comfortable air in the home. They can trap finer particles like smoke, mold spores, and viruses.
If you are still determining which type of filter is best for your home, consult a heating and cooling expert. Switching to a high-efficiency filter without ensuring that your air conditioning system can handle it could strain your equipment, putting its lifespan at risk. High-efficiency filters can also restrict airflow, which can cause various problems, including overheating and frozen coils.
Washable filters
Washable filters are a cost-effective alternative to disposables, but they also offer environmental benefits. They can last several years, saving homeowners money in the long run and reducing their landfill footprint.
These filters use electrostatic technology to attract dust particles. They are often referred to as HEPA filters. However, they do not capture microorganisms, such as pet dander, viruses and smoke. They may overtax furnace and air conditioner systems if they are not meticulously maintained.
They must be rinsed thoroughly and allowed to dry completely to prevent the development of mildew, mold and other biological contaminants in the filter. The cleaning process can be time-consuming, especially if it is done manually. Some homeowners even use grease-cutting dish soap to make the process easier. Moreover, electrostatic washable filters do not provide as much MERV arrestance as other types of filters, which may limit the performance of their HVAC system.
Carbon filters
Activated carbon filters are a must-have for anyone looking to remove odors and VOCs from their home. These harmful chemicals include formaldehyde, benzene and ammonia released from burning fuels like wood and tobacco and in some household cleaning products and building materials.
Carbon filters use a process called adsorption to trap and hold contaminants. This differs from absorption, where the molecules are chemically bonded to the absorbent material. With adsorption, the VOCs and odor-causing molecules stick to the carbon surface until the filter removes them from the air.
Buyers should ensure the activated carbon they choose has a large enough surface area to be effective. They also need to look for a high dwell time, which refers to how long the air can pass through the carbon before it’s exhausted. The more time the air spends in contact with the carbon, the better it will be filtered.
