What is a high efficiency filter, and do I need a high efficiency filter if I have a high efficiency furnace?
A high-efficiency filter captures smaller particles than a standard filter, improving indoor air quality. Even high-efficiency furnaces still need a filter matched to their airflow rating — using the wrong one can restrict airflow and strain the system.
Written by Paul Coen, Owner
What is a high-efficiency filter, and do I need one if I have a high-efficiency furnace?
A high-efficiency filter is rated to capture smaller particles than a standard filter — typically a higher MERV number — which improves the air quality circulating through your home. Having a high-efficiency furnace doesn't automatically mean you need a high-efficiency filter, though; what matters is matching the filter to your furnace's airflow rating, not just its efficiency label.
Why furnace type and filter type are separate decisions
"High efficiency" in a furnace usually refers to how much of the fuel it burns is converted into usable heat, which is a completely different spec than how finely a filter screens particles. A high-efficiency furnace can be paired with a standard filter just fine, as long as the blower is designed to handle the airflow resistance of whatever filter you choose.
What to check before upgrading your filter
- Your furnace or air handler's maximum airflow restriction rating
- The correct filter size (dimensions) for your system
- Whether a denser, higher-MERV filter will restrict airflow beyond what your blower is rated for
Using the wrong filter can strain your system even if the furnace itself is high-efficiency — our technicians can confirm the right match for your equipment. Call LJ Refrigeration Co. at (480) 948-5004.