MERV vs. static pressure
MERV rates how much a filter captures. But finer media has more resistance, and a thin (1-inch) high-MERV filter can push your static pressure past what the blower can handle — starving the coil and hurting comfort.
The better solution
A 4- or 5-inch media cabinet sized to your airflow gives you both high filtration and low pressure drop, and only needs changing every 6–12 months.