Centrifugal fans with strong air supply capacity may not necessarily have strong air suction capacity.

This depends on your specific use. Generally speaking, the flow rate is the same. The flow rate at the air inlet is equal to the flow rate at the air outlet, so the thicker the pipe, the lower the pressure. The suction at the inlet of the centrifugal fan can be measured by a simple liquid column, the static pressure at the inlet and the dynamic pressure at the outlet, and the sum of the two is equal to the total pressure. Find a transparent plastic hose, bend it into a U shape, and pour water into it. At this time, the liquid level on both sides is the same. When one end is placed at the inlet, there will be a liquid level difference on both sides, and the liquid level difference is about 100Pa per 1cm, so you can measure the static pressure. Dynamic pressure is also measured in the same way.

In addition, it is necessary to select several points to measure and take the average value.