MERV rates how effectively a filter captures particles, from roughly 1 to 16 in residential use. MERV 8 catches dust and pollen, MERV 11 to 13 catches finer particles including much of what wildfire smoke carries. Higher MERV also means more resistance, and a furnace pulling against a filter denser than its ductwork allows will lose airflow, which costs efficiency and can freeze an AC coil.
Which MERV should most homes use?
For a typical Fraser Valley home on standard ductwork, MERV 8 to 11 is the practical range. It captures what most families care about without starving the system.
If someone in the house has asthma or allergies, or you want meaningful protection during smoke season, MERV 13 is the target, but the system needs to be checked for it first.
How do you use a higher MERV safely?
The answer is usually more filter area, not denser filter. A four or five inch media cabinet holds far more surface area than a one inch slot, so it can run a higher MERV at lower resistance.
- Have static pressure measured before and after a filter change
- Move to a thicker media cabinet rather than a denser one inch filter
- Never leave a high-MERV filter in past its interval; resistance climbs as it loads
- For smoke season specifically, a dedicated air cleaner may beat pushing MERV higher
We measure static pressure as part of maintenance, so when a filter upgrade would choke a system we say so before you buy a year of them.
Ask About Filtration
We will check what your ductwork can carry before recommending a filter.