Fan manufacturers have compiled and printed the factory's fan product samples and catalogs. In the fan product samples and catalogs, ventilators are usually by series, machine number listed in a variety of rotational speeds under the selection of performance table, the table's performance parameter value is the fan's highest efficiency point of 90% range of values, and take the value of 6 to 8 performance points for selection. Roots blower is usually listed as a single species of single machine number in a certain speed under the highest efficiency point of the performance parameter values.
The use of fan performance table selection fan is very convenient. However, attention must be paid to check the actual working conditions of the air volume, wind pressure is consistent with the performance table in the inlet state. If in line with the side can be directly check the performance table selection; otherwise, it is necessary to convert the performance of the relevant formula, and then according to the converted parameters selection fan. If two or more fan performance parameters are in line with the selection of performance requirements, the fan should be from the economy, reliability and other aspects to choose the best.