When to change your air filters: breathe better, spend less

Clogged air filter’s effect on efficiency

A clogged air filter can drastically reduce the efficiency of your HVAC system. When the filter is filled with dust, pollen, pet hair and other debris, it restricts airflow. This can cause the system to work overtime to circulate air. This increased workload can lead to higher energy usage and elevated utility bills. In fact, a dirty air filter can increase your energy usage by up to 15%, according to the U.S. Department of Energy.ⁱ
A clogged air filter can:

• Make your furnace or AC system run longer to reach the set temperature
• Cause your evaporator coil to freeze in cooling mode
• Push dirty air back through your ductwork and into your home
   

When your filter is dirty, your AC system has to work harder, using more power and potentially more refrigerant to keep your home cool. Likewise, your furnace may overheat or cycle too often, which adds to your energy bill. Regular filter changes can keep your air moving properly and protect important parts of your system like the air handler, blower and thermostat.

Hidden costs of neglecting air filter replacement

While neglecting to replace your air filter can lead to increased energy usage and damage to your HVAC system, it can also pose a health risk to anyone living in the home. When your filter gets clogged, it can’t properly trap pollutants like dust, pollen and mold spores. This invisible build-up can lead to trapped moisture, musty odors and a home that feels damp and stuffy.

Although these issues may seem minor at first, they can come with serious consequences. Poor air quality can exacerbate health issues such as allergies, asthma and other respiratory conditions, especially for children, immunocompromised individuals and those with sensitivities. Mold spores, dust buildup, germs and microorganisms can thrive in a poorly maintained HVAC system, potentially posing health risks to your household. Regular air filter replacement is a simple yet effective way to help mitigate these hidden costs and promote a healthier living environment.

A cleaner home with a clean air filter

A clean air filter can also play a crucial role in maintaining a cleaner home. By effectively capturing airborne particles, a clean filter reduces dust buildup on surfaces and minimizes the presence of pollutants. This leads to a more hygienic living space and can even alleviate allergy symptoms. Improved air quality contributes to overall comfort and well-being, helping to make your home a healthier place to live.

How often should you change your air filter?

The frequency of air filter replacement depends on several factors, but a good rule of thumb is to change your filter every 1-3 months. Some high-efficiency filters can last up to 6 months, but they should be checked regularly to ensure they remain effective. Keep in mind that every home is unique, and you may need to change your filter more or less often depending on varying factors, like:

• The type of filter being used, like pleated versus fiberglass filters
• Whether you have pets, which increases dander and hair in circulation
• If anyone in your household has allergies or respiratory issues
• How frequently your HVAC system runs, which may be more often in the summer months

Once you’ve determined how often you need to change your filter, you can establish a consistent replacement schedule. Set reminders on your phone or a smart home device for each month your filter will need to be changed during the year. This can help you make sure you don’t miss a scheduled replacement.

Signs that your HVAC filter needs to be changed

It's important to recognize the signs that your air filter needs changing. Keep an eye (and nose) out for these common warning signs:

• Your AC or furnace runs longer than usual
• Airflow feels weak or rooms aren’t heating or cooling evenly
• You see dust blowing from the vents or building up quickly on surfaces
• Your energy bills increase without a change in usage
• There’s a musty or dusty smell when the system is running
   

Additionally, humidity levels can impact filter performance; high humidity can cause filters to become damp and less effective. So, regions that experience high humidity levels may need to change their filters more frequently to maintain efficiency. Regularly inspecting your filter and monitoring these signs can help you determine when it's time for a replacement.

Choosing the right filter for your HVAC system

Selecting the right air filter for your home is crucial for achieving optimal filtration efficiency. Filters are rated by their Minimum Efficiency Reporting Value (MERV), which measures their ability to capture particles. Higher MERV ratings indicate better filtration but may restrict airflow if your system isn't designed to handle them.

Common MERV ratings:

• MERV 1–4: Basic filters that catch large debris, but not much else
• MERV 5–8: Ideal for most homes; these trap common particles like dust, lint and mold spores
• MERV 9–13: Great for families with allergies or pets; captures finer particles like pollen and pet dander
• MERV 14+: Very effective filtration (similar to hospital-grade), but may restrict airflow if your system isn't built to handle them

In addition to MERV ratings, the material and type of filter also matter. Here are the most common air filter types:

• Fiberglass filters: If you need an inexpensive and disposable option, fiberglass filters offer minimal filtration (typically MERV 1–4) and are best for basic use or short-term needs.
• Pleated filters: If you want better overall performance, pleated filters are made with dense material that traps smaller particles more effectively. They’re commonly used in homes with MERV ratings between 7 and 13.
• Washable or reusable filters: If you're looking for a more eco-friendly or budget-conscious option, washable or reusable filters might work for you. Just be sure to clean your reusable filter regularly and let it dry completely before putting it back. Otherwise, they can grow mold or become less effective over time.
   

HEPA filters also offer top-tier filtration power, but they’re not compatible with all HVAC setups due to their density. It’s important to consult your AC manual or speak with a licensed HVAC technician so you can make an informed decision on the best type of air filter and filtration rating for your home.

Maintaining comfort and energy savings with small changes

Changing your HVAC air filter might feel like a small chore, but it plays a major role in maintaining a healthy, efficient home. A clean, high-quality filter not only improves your indoor air quality by capturing dust, allergens and other pollutants — it also helps your HVAC system run more efficiently and last longer.

Choosing the right filter is an investment in your comfort and your system’s performance. It’s a simple step that pays off in cleaner air, lower energy bills and fewer maintenance headaches.

At Direct Energy, we’re here to help you take control of your home’s energy use. Whether it’s expert tips to boost efficiency or flexible electricity plans tailored to your lifestyle, we’re committed to empowering your energy choice.