As a homeowner, it’s important to pay close attention to the air filters in your home’s HVAC system. Air filters are an essential component of an AC system, as they protect it from harmful particles that can interfere with its performance and cause damage.
How Air Filters Work
Air filters essentially trap pollutants and contaminants that are present in the air before they can enter your living space. Pollutants like dust, pollen, and mold can cause respiratory issues or allergies, so it’s important to effectively filter these out of the air that circulates in your home.
Different Types of Air Filters
There are several types of air filters available for homeowners to choose from, including:
- HEPA filters – the highest level of filtration available on the market, these filters remove up to 99.97% of particles. They are not always practical for residential HVAC systems due to their density and can be quite costly.
- Fiberglass filters – these filters are available at most home improvement stores and are low-cost options. They are not as efficient in capturing small particles but provide basic filtration.
- Pleated filters – composed of dense mesh materials that are folded like a fan, these filters provide better particle trapping than fiberglass but tend to have a higher cost.
- Electrostatic filters – these filters use static electricity to attract pollutants and particles, and they are typically seen as an upgrade to both fiberglass and pleated filters.
- Washable filters- These filters can be reused after cleaning but provide mild filtration.
MERV Ratings
Air filters are rated according to their Minimum Efficiency Reporting Value (MERV), which indicates their efficiency in trapping particles. This was a system designed by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) to categorize the different levels of filtration that different products offered. The scale they created runs from 1 to 16, with higher numbers representing higher efficiency in particle removal. However, some residential HVAC systems are not optimized to handle higher MERV-rated filters since the HVAC systems that most consumers select are simply not capable of forcing enough air through them efficiently.
As such, it’s important to cross-reference and pick the MERV rating your system can handle before purchasing.
First of all, let's define the MERV rating system and levels for you. MERV stands for Minimum Efficiency Reporting Value and it's a rating system used to describe how effectively an air filter removes particles from the air. This rating typically ranges from 1 to 16, with higher numbers indicating a better filtering capability.
Here are some specific MERV rating levels and what each signifies:
MERV 1-4:
These filters are inexpensive and typically made of fiberglass. They capture large airborne particles, such as pollen and dust mites, but are not effective at removing smaller particles.
MERV 5-8:
These filters are generally made of pleated filter material and are more effective at removing smaller particles, such as pet dander and mold spores.
MERV 9-12:
Filters in this category are even more effective at capturing smaller particles, including some bacteria and smoke particles.
MERV 13-16:
These are the highest-rated filters and are capable of removing the smallest particles, including viruses and some gases.
It's important to choose the right MERV rating for your HVAC system and home size. A filter with a higher MERV rating may not be suitable for your system and could actually reduce the airflow, which can damage your system. On the other hand, a filter with a lower MERV rating may not effectively capture the particles in your home.
For example, if you live in an area with high pollen counts, a MERV 8 filter might be a good choice to effectively capture those particles. Likewise, if you have pets in your home, a MERV 10 filter would capture more pet dander than a MERV 6 filter.
When to Switch Out Filters
Air filters should be changed regularly. For typical residential use, it's best to change it every 3 months or as recommended by the manufacturer. But variables like the number of people in the household, pets, or any remodeling going on can cause the filter to fill quicker. It's important to be diligent and inspect the filter every month to make sure there is no obvious buildup.
Additionally, proper attention to switching out filters on time will help prevent you from needing emergency air conditioning repair.
The Dangers of Using Dirty or Incorrect Air Filters
A dirty or incorrect air filter can result in poor indoor air quality and also cause damage to your AC system over time. Dirt and particles block the air flow and cause the AC system to work harder to circulate air. This strain increases the likelihood of repairs or potential replacement of the system as the efficiency decreases.
In conclusion, selecting the right air filter for your AC system is an essential component of great indoor air quality, energy savings, and making sure your system functions properly. Consider the air filter type and the MERV rating that’s appropriate for your HVAC system, and don't forget to change your filter regularly to keep your system operating smoothly.
Stay cool and stay healthy!
