When selecting dust collector, another point of consideration is air-to-cloth ratio. The air-to-cloth ratio is the volumetric flow rate of air (m³/minute) flowing through a dust ollector’s inlet duct divided by the total cloth area (m²) in the filters. The result is expressed in units of velocity

Estimating a air-to-cloth ratio that is too high, compared to a correctly estimated air-to-cloth ratio, leads to higher pressure drops, higher particle penetration (lower collection efficiency), and more frequent cleaning that leads to reduced fabric life.

Estimating a air-to-cloth ratio that is too low increases the size and cost of the baghouse unnecessarily.

The below table gives a factor method for estimating the ratio. However consideration of particle and grain loading must be taken into account by designer before the dust collector has been built