How Often Should You Change Your Furnace Filter?

Many homeowners put their comfort on autopilot, forgetting to tackle one simple yet critical HVAC maintenance task: Replacing the furnace air filter. The trouble is that over time your furnace filter becomes clogged with dust, pet dander, and airborne particles, forcing your system to work harder to maintain efficiency. This is not only hard on your furnace but also drives up energy bills.

So how often do you need to change out your furnace air filter? The answer might surprise you.

Furnace Filter Basics

What They Do

Furnace filters are your home’s first line of defense against airborne contaminants like dust, pet dander, pollen, and mold spores.

These simple devices sit between the return ducts and the furnace blower. As your heating system pulls in air from your home, the filter traps particles before they enter the furnace.

Furnace filters serve two purposes: First, they protect your furnace from contaminants that can cause damage or reduce efficiency. Second, they improve indoor air quality by taking allergens out of circulation.

Furnace Filter Types

There are several types of furnace filters, including:

• Fiberglass filters: These disposable, cost-efficient filters offer basic protection. While they are efficient at capturing larger particles, they often miss smaller allergens and need frequent replacement.
• Pleated filters: Made from polyester or cotton paper, which is folded into pleats, these filters trap smaller particles, offering more protection than basic fiberglass filters. 
• High-Efficiency Particulate Air filters (HEPA): These filters capture 99% of particles, and while they are excellent for improving air quality, not all HVAC systems can accommodate HEPA filters.
• Washable Filters: An eco-friendly alternative to disposable options, washable filters are typically made from aluminum or synthetic materials with an electrostatic charge that attracts dust and debris. Once they get dirty, just give them a rinse, allow them to dry, and reinstall.

Understanding MERV Ratings

To make an informed decision about which furnace filter is right for you, you need to understand minimum efficiency reporting value (MERV). The best way to think of it is the higher the MERV number, the more protection it offers. 

• MERV 1-4 filters offer basic protection, filtering out large particles, dust mites, and pollen.
• MERV 5-8 filters trap smaller particles, including mold spores, pet dander, and dust.
• MERV 9-12 filters capture fine particles, including vehicle emissions and even some bacteria. These filters are ideal for people with pets or mild allergies.
• MERV 13-16 filters capture microscopic particles, including smoke, cooking oil, and most bacteria. Note: These filters may significantly restrict airflow and are not designed for all HVAC systems.

Signs You Need Furnace Filter Replacement

The best way to determine if your air flow filter needs replacement is to give it a good visual inspection. Clean filters are crisp and white, while dirty ones are grey or black with visible dust and debris. Hold your filter up to the light. If you can’t see light passing through it, it’s time for furnace filter replacement.

Here are other signs to look out for:

High Energy Bills

Notice a sudden spike in your monthly energy bill? Your dirty air filter may be the culprit. A clogged filter forces your HVAC system to work harder to maintain efficiency. In fact, we’ve seen severely restricted filters reduce efficiency by as much as 15%.

Reduced Airflow

While your HVAC system is running, place your hand over a register. Restricted airflow is a telltale sign you need an air flow filter replacement. Ignoring HVAC maintenance not only reduces comfort but also puts unnecessary stress on your system.

More Dust

Are you cleaning more often than usual? When filters become clogged, dust begins recirculating through your home. If you see excess dust, especially around your vents, it’s either time for a good cleaning, furnace filter replacement, or both!

System Running Longer Than Usual

A clean filter allows your furnace to reach temperatures quickly. However, when airflow is restricted, your system begins running longer heating cycles to maintain your desired temperature. If your furnace is working overtime, it’s likely time for air flow filter replacement.

Trust Stephens With Your Furnace Filter Replacement Needs

Whether you have questions about air filters, need routine maintenance, or want to improve air quality, we can help. Stephens Plumbing, Heating & Air Conditioning is here to save you time, money, and stress by offering comprehensive HVAC maintenance services. Keep your system running at peak condition! Contact us today to schedule service.