Everything You Need to Know About Air Filters

You might make it a point to replace your air filters every month, but you might be surprised to learn that those flat rectangles make a major impact when it comes to the performance of your HVAC system. Without air filters, dust, dirt, and allergens would circulate throughout your home, causing respiratory problems and lowering the overall air quality. Here’s a guide to everything you need to know about these powerful, yet misunderstood, products.

How Air Filters Work and Why You Need Them

An air filter serves two important purposes: one, to keep the HVAC system clean, and two, to keep airborne contaminants from polluting the air in your home. Air filters keep the HVAC system clean and free from dirt and dust through trapping these particles before they can reach the system. This allows the system to maintain its efficiency, saving you money on your energy bills in the process.

After warm or cool air is brought into your home through the HVAC system, the filter catches airborne particles like dust, pollen, mold, and bacteria. The concentration of some pollutants can be 2 to 5 times higher indoors than outdoors, due to factors such as synthetic building materials and fumes from household cleaners. Without a filter, these particles would circulate in your home, polluting the air and causing problems for those with allergies or other respiratory conditions.

How Often to Change Air Filters

A dirty air filter decreases the overall efficiency of your HVAC system. Replacing a dirty filter with a clean one can lower the system’s energy consumption by anywhere from 5 to 15%. We recommend that you replace your filters at least once every three months. If you have pets, or if someone in your home has allergies, it’s best to replace your filters every month.

Understanding MERV Ratings

MERV stands for minimum efficiency reporting value. The MERV rating scale ranges from 1 to 20 and tells you how effective different air filters are at removing certain kinds of airborne particles. Each level of MERV rating builds on the previous one, and a higher MERV rating indicates greater filtering capabilities.

MERV 1-4: Removes dust mites, pollen, dust, textile and carpet fibers

MERV 5-8: Removes pet dander, dusting sprays, mold spores, and pet dander

MERV 9-12: Removes lead dust, flour, and auto emissions

MERV 13-16: Removes cooking oil, smoke, bacteria, and sneeze droplets

MERV 16-20: Removes viruses and all forms of smoke

Any filter with a MERV rating of 16 or higher is categorized as a High Efficiency Particulate Air, or HEPA, filter. These filters provide the highest level of protection from airborne contaminants, and are commonly used in hospitals, airplanes, schools, and other places where controlling the spread of airborne disease is important. HEPA filters are also available to purchase and use in your home. In fact, many allergy sufferers notice significant improvement from using a HEPA filter.

If you’re considering purchasing a filter with a higher MERV rating, consult with an HVAC professional first. Filters with higher MERV ratings may require an upgrade or replacement of your existing HVAC system. This is because the filters block so much air that the HVAC system needs to be powerful enough to compensate.

Types of Air Filters

There’s no one-size-fits-all solution when it comes to air filters.  Each filter has its own benefits, drawbacks, and ideal environment. Along with selecting the right type of filter for your home’s needs, it’s important to ensure you choose the right size as well. A filter that’s too small won’t be able to keep particles from squeaking past it, while a filter that’s too big won’t fit in the first place. So, keeping sizing in mind is important as you learn the differences between the main types of air filters.

Fiberglass filters

Fiberglass filters are the most common type of HVAC filter. These filters are comprised of layered fiberglass fibers arranged to form the filter itself, as well as metal grating to support the fiberglass and prevent the filter from losing its shape.

While fiberglass filters are disposable, inexpensive, and generally effective, they lack the higher MERV rating of more high-tech filters. For trapping common household dust, fiberglass filters are more than enough. However, if you or someone in your home has respiratory problems, it’s best to look for a more powerful filter.

Pleated filters

Pleated filters are made of polyester or cotton. Dense pleats allow these filters to trap more dust, dander, and pollutants than standard fiberglass frames. The tradeoff that comes with pleated filters is air quality vs efficiency. Since the filters are so dense, your HVAC system will have to work harder to pull air through the unit. This results in a loss of energy efficiency and a possible increase in your monthly energy bills. However, this tradeoff may be worth it if improving indoor air quality is your main priority.

Electrostatic filters

With the help of cotton or paper fibers, electrostatic filters generate a static charge when in use. This charge acts as a magnet that attracts small airborne particles and stops them from circulating in your home. Because even the smallest airborne particles can’t escape the electric charge, electrostatic filters are a great choice for allergen removal.

HEPA filters

HEPA filters are the strongest filters commercially available. They’re effective in trapping up to 99.97% of contaminants, according to the U.S. Department of Energy. For the cleanest and healthiest possible air, there’s no better option than HEPA Filters. However, HEPA filters can drastically reduce your system’s airflow, which can result in higher energy bills.

Many filters advertise themselves as “HEPA-like” or “HEPA-type”. This is because, legally, they cannot be categorized as actual HEPA filters as they do not fulfil the requirement of trapping up to 99.97% of airborne particles. To make sure you’re getting a legitimate HEPA filter, look for filters labeled as “true” or “absolute”. While they’re more expensive, it’s the only way to ensure you get true HEPA performance.

If you want the air purification benefits of a HEPA filter without compromising the energy efficiency of your HVAC system, consider purchasing a vacuum cleaner with a HEPA filter. The HEPA filters in vacuum cleaners are just as effective as the ones made for HVAC systems. In other words, they’re another great way to effectively remove pet dander, dust, dirt, and other allergens from the surfaces and fabrics in your home.

Let Chas Roberts Help You Breathe Easy

Whether you’re in the market for new air filters or wondering if it’s time to replace your HVAC system altogether, contact Chas Roberts. Our technicians are experts at creating comfortable living environments, and never pressure you into purchasing equipment or products you don’t need. With our help, you can ensure that the air in your home is free of harmful pollutants and safe for you and your family.