Selecting the right HVAC filter is essential for air quality, energy efficiency, and the long life of your system. HVAC filters are available in many sizes and ratings for different filtration needs. We’ll explore the types of filters suitable for residential use, how to understand their ratings, and the recommended replacement frequency of each kind.
Understanding MERV Ratings
The industry rates HVAC filters using the Minimum Efficiency Reporting Value (MERV) scale. This scale measures the filter’s ability to trap particles between 0.3 and 10 microns in size. Although the MERV scale runs from MERV 1 to MERV 20, residential filters typically range from 1 to 13.
MERV 1-4
These filters offer the most basic filtration level, capturing large particles like lint and dust. They have a minimal impact on indoor air quality.
MERV 5-8
These filters are standard for many homes. They trap mold spores, pet dander, and pollen.
MERV 9-12
MERV 9-12 filters filter finer dust, such as that as small as flour dust. These filters offer a higher filtration performance.
MERV 13
MERV 13 is the highest scale rating recommended for residential HVAC systems. Although MERV 14 and 15 options are also available, these can often reduce airflow. MERV 13 filters can trap smoke, smog, and some airborne viruses.
We do not recommend filters above MERV 13. They are incompatible with most residential HVAC systems unless specially modified to prevent airflow restrictions.
Fiberglass Filters (MERV 2-4)
Fiberglass filters have a lifespan of about 30 days. They are the most basic HVAC filter, consisting of a thin mesh of spun glass fibers that captures large particles. Fiberglass filters are best for homes without pets or allergies.
Change your fiberglass filter every 30 days because as it clogs, it loses effectiveness. Fiberglass filters are affordable but offer minimal protection.
Pleated Filters (MERV 5+)
Pleated filters last 60 to 90 days. Manufacturers make them from cotton or polyester folded into pleats to increase the surface area and capture more particles. These filters offer improved filtration without compromising airflow.
You should replace pleated filters every two to three months. However, more frequent changes may be necessary with pets or high dust levels.
Electrostatic Filters (MERV 1-4)
Electrostatic filters attract particles through static electricity. They are washable and, with proper care, can last five to 10 years. Neglecting cleaning reduces airflow and has the potential to affect indoor air quality.
Washable Filters
Washable filters, often made from aluminum or plastic frames with synthetic fiber mesh, are designed for long-term use. You must clean them monthly to remove buildup and maintain performance.
These filters protect your HVAC system and improve indoor air quality. After washing these filters, let them dry entirely before putting them back in place to avoid mold growth.
Media Filters (MERV 8-13)
Media filters are thicker and contain sand, peat, foam, or crushed glass. Their extended surface area allows for high filtration capacity without compromising airflow. These filters can last six months to a year. While more expensive upfront, many homeowners in Wheat Ridge feel they are worth the cost due to their longevity and performance. Media filters can trap pollen, dust, mold, and some bacteria.
Filter Sizes and Fit
Residential HVAC filters come in standard sizes like 16 x 20 x 1, 20 x 25 x 1, and 16 x 25 x 4. Using the incorrect filter size can reduce system performance, cause air leaks around the frame, and increase the strain on the blower motor. Our technicians can offer guidance to help ensure you use the proper size.
Choosing the Right Filter for Your Home
Selecting the best HVAC filter depends on system specifications, household needs, and indoor air quality goals. Consider the following factors to choose wisely.
Budget-Minded Households
If your family is on a budget, consider fiberglass or basic pleated filters with MERV ratings 6-8. Change your filter monthly to protect your HVAC system.
Families With Children or Pets
Pleated filters rated MERV 8-11 give you the ideal balance between filtration and airflow. The increased surface area will help filter more pet hair and dander than a basic fiberglass filter.
Homes With Allergy Sufferers
Choose a MERV 11-13 pleated or media filter. They can help you control your allergy symptoms for greater comfort.
We caution you to never force a high-rated filter into a system that can’t accommodate it. Increased resistance can cause pressure imbalances, short cycling, and blower motor strain.
Is It Time to Replace Your Filter?
Even if you follow a regular filter change schedule, you should monitor the condition of the filter. Monitoring ensures consistent comfort and system longevity. You may need a filter change if you notice the following.
- Visible dirt
- Allergy flare-ups
- Higher energy costs
- Reduced airflow
- Unusual HVAC noise
When in doubt, it is always best to replace your filter. A clean filter will help your HVAC system work more effectively.
How Pets and Household Habits Affect Filter Lifespan
Not all homes put an equal strain on HVAC filters. Daily activities and who lives in the house can directly affect how often you change the filter.
Cooking, Smoking, and Scented Products
Kitchens with poor ventilation expose HVAC filters to fine grease particles and smoke. They can cling to the filter fibers and create an invisible buildup that reduces airflow and efficiency, requiring more filter changes and general HVAC maintenance.
Additionally, indoor smoking accelerates filter contamination. Tobacco smoke releases many particulates into the air, reducing filter lifespan and causing lingering odors throughout the ductwork.
Even candles, incense, and aerosols lead to filter contamination. Soot and vaporized oils from scented products are small enough to be pulled into the return ducts and trapped in higher-rated filters.
Can Upgrading Your Filter Improve System Performance?
Many homeowners in Wheat Ridge assume that installing a higher-rated filter will automatically improve system performance. However, more filtration is not always better.
The MERV rating of a filter affects how much resistance it creates. Higher resistance can strain the blower motor, reduce airflow through the ducts, and force the system to work harder. Before upgrading to a higher MERV rating, consider a few things.
- System compatibility
- Airflow needs
- Energy costs
An improperly matched filter can raise energy costs instead of lowering them. The best strategy is not to choose the highest MERV rating but the one that balances filtration, airflow, and system efficiency.
An appropriately rated and regularly changed filter will improve indoor air quality more than an overpowered filter changed at inappropriate intervals.
We can inspect your system and perform measurements to determine its filter capacity. Our technicians will answer your questions and guide you in your selection.
Trust Us for Expert Filter Guidance
Fox Heating, Cooling & Plumbing opened in 2018 and offers knowledgeable heating and cooling services and solutions. We are a local family business with over four generations of HVAC professionals and provide free estimates and quality workmanship every time.
Contact our HVAC experts at Fox Heating, Cooling & Plumbing if you need filter guidance in Wheat Ridge.
