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What Is the Best AC Filter To Use During Allergy Season?

Tips for Finding the Best HVAC Filter To Fight Off Allergies

Spring is here, and with it come warmer days, greener hills, and beautiful blossoms of every kind. Unfortunately, spring also brings a host of airborne allergens that can make the gorgeous, pleasant days pretty hard to enjoy. Homeowners who are hit especially hard every spring may find themselves at the end of their rope when it comes to keeping allergies at bay. 

Retreating indoors is the common instinct, but since indoor air is constantly recycled and recirculated, any airborne pollutants that make it inside tend to get trapped and build up to high concentrations. That’s where the HVAC filter comes in. Its job is to capture pollutants as the unit pulls in air to be cooled and distributed throughout the house. But not all filters are created equal. Read on to learn about the different types of filters and their relative efficacy at warding off allergies.

Fiberglass Air Filtersfibreglass filter

Fiberglass AC filters are the most common and least expensive filters around. They are made from spun glass fibers, which form a porous barrier to capture particles. These allow for powerful airflow, but as a result, they are not very effective at stopping smaller particles. To understand why it’s helpful to look at the MERV rating of fiberglass filters.

Simply put, the MERV (minimum efficiency reporting value) rating of an HVAC filter denotes its efficiency at capturing airborne particles, with 1 being the least efficient and 16 being the most efficient. Fiberglass filters have a MERV rating of around 1 to 4, which means they only capture a fairly small percentage of particles. They also tend to become clogged very quickly, so it’s imperative to replace them every 30 days or so.

Reusable or Washable Air Filters

Next up are reusable filters, which capture particles by filtering air through several layers of woven polypropylene or similar material, each of which holds an electrostatic charge. This static electricity gives airborne particles a positive charge, essentially causing them to become attracted to the filter and stuck in place.

Many homeowners like these filters because they tend to last for many years and can be unplugged and washed with water rather than replaced outright. However, these also have a MERV rating of around 4 or lower, which means they aren’t very effective against common, small-particle allergens like mold and pollen.

HEPA Air FiltersHEPA filter

Finally, there are HEPA (high-efficiency particulate air) filters. These heavy-duty filters don’t mess around when it comes to capturing even very tiny particles - hence the name. These actually go beyond the standard MERV scale, as they can effectively trap a very high percentage of just about any particulate matter, including mold, pollen, dust mites, bacteria, and even smoke.

These are undoubtedly the best filters for those who suffer from allergies. The trouble is, they are very dense and can severely constrict airflow if the AC unit isn’t powerful enough to handle it - which can damage the unit or cause it to wear out prematurely. A pleated filter with a mid-to-high MERV rating may do the trick for some homeowners, but those who get knocked down by allergies may need the comprehensive protection of a HEPA filter. 

In any case, it’s always best to consult with an HVAC professional to determine whether the AC unit can handle a given filter type without sacrificing unit efficiency.

About Chad’s AC Direct

The friendly experts at Chad’s AC Direct have been delivering superior service to the Montgomery, Alabama community for years. Their licensed and background-checked technicians are punctual, respectful, and don’t work on commission - which means they’ll never upsell or recommend unnecessary products. They always offer transparent, flat-rate pricing, 24/7 emergency AC service, and an airtight satisfaction guarantee on every job.