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4" AC Filters and Furnace Filters
Improve your home’s air quality and reduce HVAC strain with the right 4-inch filter. These deeper filters offer more surface area, better airflow consistency, and longer service life than standard 1-inch filters. We carry every common 4" size plus hard-to-find dimensions used in older or high-performance systems. If you don’t see your exact size, we can build a custom 4-inch filter for you.
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Made in USA
Reliable Customer Support
“HVAC systems are complex investments that deserve quality filters. We work with contractors and homeowners alike to ensure every system gets the filtration it needs for peak performance and longevity.”
Shop by 4-Inch Filter Size
Find your exact 4-inch filter size below. From popular sizes like 16x25x4 and 20x25x4 to uncommon dimensions, we have options for all HVAC systems. If your size isn’t listed, we can build a custom filter that fits your unit perfectly.
Need a different filter size?
If your system doesn't use a 4-inch filter, shop our full lineup of 1", 2", 3", 5", 6" and custom-size air filters. We'll help you find the exact fit for your HVAC system.
Shop HVAC Filters by System Type
Different HVAC systems have different filtration needs. Choose the right filter based on your specific heating, ventilation, and air conditioning setup.
- For Residential HVAC Systems: Standard pleated MERV 8-11 filters provide excellent air quality improvement while maintaining proper airflow for efficient operation.
- For Commercial HVAC Systems: Higher-capacity filters and custom sizes accommodate larger air handlers and higher air volume requirements in office buildings and facilities.
- For Industrial Applications: Heavy-duty filters designed to handle challenging environments with higher dust loads and extended replacement intervals.
Shop HVAC Filters by MERV Rating
MERV ratings help you balance air quality goals with system performance. Higher ratings provide cleaner air but require more powerful HVAC systems.
- MERV 6-8: Ideal for most residential HVAC systems, capturing common household particles while maintaining good airflow.
- MERV 9-12: Enhanced filtration for homes with pets, allergies, or higher air quality standards.
- MERV 13-16: Commercial-grade filtration for superior air quality in offices, medical facilities, and high-end residential applications.
When we founded AC Filters 4 Less over a decade ago in Coral Springs, Florida, our goal was simple:
help homeowners and businesses find the right AC and furnace filters for their systems at fair prices.
We built our reputation on personal service, expert advice, and genuine care for your indoor air quality.
As we pass the torch to the next generation, we’re proud to keep that same commitment — helping families stay warm and breathe cleaner air all winter long.
The same reliable quality, the same family values — just focused on keeping your furnace running efficiently this season.
- Warm Regards,
Mark and Michelle Platt, Founders
Trusted by thousands of customers annually since 2010.
FAQs – AC Filters & HVAC Systems
Why does a 4-inch filter sometimes measure 3.75 inches?
Are 4-inch filters better than 1-inch or 2-inch filters?
How often should I replace a 4-inch filter?
What MERV rating should I choose for a 4-inch filter?
Can I replace a 4-inch filter with a 1-inch or 2-inch filter?
Why are 4-inch filters more expensive?
