Your furnace filter plays two important roles in your home. It protects the internal components of your HVAC system by trapping dust and debris, and it also improves indoor air quality by capturing airborne contaminants. Proper filter maintenance keeps your furnace running efficiently and helps maintain a healthier living environment all winter long.
How To Check Your Furnace Filter
Your furnace filter is typically located inside the return duct or the filter slot near your furnace. Check the filter every month, especially during the winter heating season. To inspect it, remove the filter and hold it up to a light source. If light passes through easily, the filter likely still has life left. If it looks clogged or you cannot see light through it, it is time to replace it.
Most homeowners should replace their furnace filter every one to three months. However, some households may require more frequent changes. Homes with multiple pets produce more dander, and homes with smokers experience heavier airborne particulates. Certain cleaning products that contain volatile organic compounds can also cause filters to clog more quickly.
Filter Sizing
A furnace filter only works properly when it fits the filter slot correctly. A filter that is too large will not fit at all. One that is too small allows air to bypass the filter, leaving your system unprotected. To determine the correct size, remove your existing filter and check the printed dimensions. Filters are listed by height, width, and thickness.
Filter Rating
Every furnace filter has a MERV rating, which stands for minimum efficiency reporting value. This rating indicates how effectively the filter captures particles.
MERV 1 to 4 filters catch large particles such as dust and lint. They offer basic system protection but do not significantly improve indoor air quality.
MERV 5 to 8 filters are a common choice for homeowners. They capture dust mites, mold spores, and some pet dander while maintaining good airflow.
MERV 9 to 13 filters provide better filtration for fine particles such as smoke, small allergens, and fine dust. These are ideal for households with allergies, asthma, or respiratory sensitivities.
Types of Furnace Filters
There are three main types of furnace filters available.
Fiberglass filters are the most affordable disposable option. They usually have a MERV rating of 1 to 4 and help protect your furnace from large debris, but they do not improve overall air quality. These filters typically last about 30 days.
Pleated disposable filters are popular because they offer better filtration and have a larger surface area. They are still affordable and usually have a MERV rating between 6 and 13. Most pleated filters last two to three months.
Washable or reusable filters can be cleaned and reused for a year or longer. However, they typically have lower MERV ratings, often in the 1 to 4 range. They require regular cleaning to prevent mold and moisture buildup.
Top Signs It Is Time for a Filter Change
Certain warning signs can tell you that your filter needs attention. Reduced airflow from your vents is one of the first signs of a clogged filter. A dirty filter forces your furnace to work harder, which can lead to longer run times and higher energy bills.
You may also notice more dust around your home, or your HVAC system may seem louder than usual. Allergy or asthma symptoms may worsen if your filter is no longer trapping airborne irritants effectively.
Reliable Furnace Maintenance Service
KW Lang Mechanical provides expert furnace maintenance in Cleveland, OH. We also offer professional repair, installation, and replacement services to keep your home warm and efficient. Contact us today to schedule your next service appointment.
