While most manufacturers suggest that you change your air filter every two to three months, this can vary depending on several factors, such as the type of air filter you have in your HVAC system and whether or not you have pets. Here’s a more in-depth look at why AC filters are important, what types are available, and when you should change them.
The Role of an AC Filter
An AC filter’s basic role is to ensure the air circulating through your HVAC system is clean. But how exactly does it work? When you place your filter within the air duct, it acts as a barrier, preventing debris from entering your HVAC system. Most air filters can block bacteria, mold, dust, lint, and pet hair from entering your system and circulating throughout your home. There are several benefits that an AC filter provides:
- Improves your indoor air quality by filtering out contaminants
- Protects your HVAC system by ensuring debris doesn’t clog the unit
- Promotes energy efficiency by ensuring your HVAC system doesn’t overwork itself
Not all filters are created equal, though. The size and type of pollutants air filters manage to keep out will depend on their MERV rating.
MERV Ratings and What They Stand For
The MERV rating, or Minimum Efficiency Reporting Value, rates how efficiently AC filters trap contaminants. The higher the MERV rating, the more efficient the air filter.
- MERV 1-4: Filters within this range can trap larger particles, such as pollen, lint, and dust.
- MERV 5-12: Filters within the 5-12 range can trap smaller particles, such as dust mites, mold spores, and pet dander.
- MERV 13-16: Filters within this range can trap even smaller particles, such as viruses, smoke, and bacteria.
- MERV 17-20: Filters within this range can trap very fine particles and are rarely used for residential purposes. They’re more common in hospitals.
The Types of AC Filters and How Often They Should Be Changed
How often you should change your AC filter will also depend on the type of filter you have. Here are the filters available on the market.
Fiberglass Filters
Fiberglass filters are made of a metal grate and spun glass. While they can trap larger contaminants, such as dust or lint, they aren’t very effective at filtering out smaller particles. Due to their low MERV rating of between 1-4, fiberglass filters aren’t recommended if you suffer from allergies or have respiratory issues. They should be changed every 30 days.
Pleated Filters
Pleated filters contain multiple layers of pleated material. The pleat design increases the surface area, allowing the filter to trap more contaminants than fiberglass filters. Pleated filters come in different thicknesses and MERV ratings (1-16). The 1-inch filters should be replaced every 2-3 months, while the 4-inch filters should be replaced every 3-6 months.
Washable Filters
Washable filters are an environmentally friendly alternative to disposable filters. Made from electrostatic polypropylene, they are designed to trap dust and debris via filtration and static electricity. Many washable filters have a low MERV rating of between 1-4, which makes them unsuitable for those with allergies. Washable filters should be cleaned every 30 days.
Electrostatic Filters
Electrostatic filters use static electricity to trap debris and contaminants. With a MERV rating of between 5-8, they are effective at trapping smaller particles, such as pet dander, pollen, and dust. Both washable and disposable electrostatic filters are available, and they must be cleaned or changed monthly.
HEPA Filters
With a MERV rating of 17 or higher, HEPA filters are the most powerful of the AC filters and can block 99.97% of particles 0.3 microns in size. While HEPA filters can do an exceptional job of keeping your indoor air quality clean, not all HVAC systems are designed to accommodate these filters. And because of their dense design, they can restrict airflow. HEPA filters should be changed every 6-12 months.
The Factors That Affect How Often You Should Change Your AC Filters
While the above is a general rule for how often you should change your AC filters, the truth is, the frequency does depend on several factors. These factors include:
You Have Pets
If you have pets in the home, you should change your filters more frequently. Check your filters monthly to see how much pet hair and dander have accumulated on the filter, then decide whether a monthly change is necessary.
People With Allergies or Respiratory Issues in the Home
If you have family members who suffer from allergies or respiratory issues, make sure to invest in a filter with a higher MERV rating and change it more frequently.
Neighborhood Has High Levels of Pollution
If you live in a neighborhood that has high levels of dust or is near a freeway, you will probably need to change your filters more frequently.
How Often You Use Your HVAC System
Another factor is how often you use your AC. In cities with high humidity, such as Miami, your AC may see constant use between late May to early September. During this period, it’s a good idea to change your AC more frequently.
The Consequences of Not Changing Your AC Filter
Are there consequences to not changing your AC filter or simply forgetting to change it regularly? Absolutely! Here are some of the problems you’ll face.
Strain on Your AC
A clogged filter prevents proper airflow, which forces your AC to work harder. This strain may not only cause a breakdown, but over time, it could eventually shorten the AC’s lifespan.
Higher Energy Bills
An overworked AC means the unit will stay on longer trying to reach your desired temperature. Unfortunately, this will translate to higher energy bills.
Reduced Indoor Air Quality
A clogged AC filter will no longer be able to trap debris and contaminants in the air. This can significantly reduce your indoor air quality.
Maintenance Services From One Hour in Miami
Changing your AC filters is a job you can easily do to help maintain your AC. However, other tasks should be left to professional technicians, like our team at One Hour Air Conditioning & Heating in Miami. We can clean the coils, check the refrigerant, calibrate the thermostat, and lubricate the system. And if you’d like to discuss purchasing a filter with a higher MERV rating, we can give you options.
We highly recommend scheduling annual maintenance services. When you hire One Hour Air Conditioning & Heating, you’ll get experienced technicians, prompt service, and transparent pricing. In fact, our motto is, “We’re on time or you don’t pay a dime.”
Contact us today to make an appointment!
