primary panel filter, dust pre filter, air conditioning filter，PrimaryAirFilter ，HVACFilter ，PreFilter ，PaperFrameFilter

Our paper frame primary air filter is an economical disposable pre-filter for HVAC and air handling units. It adopts sturdy cardboard frame and pleated synthetic fiber media, capturing coarse dust, lint, hair and particles above 5μm. Low air resistance ensures stable airflow. It works as the first filtration stage to protect downstream medium and high efficiency filters, greatly extending their service life. Lightweight structure enables quick installation and direct discard after use, no cleaning required. Custom sizes are supported for commercial buildings, offices and factory ventilation systems.