| 摘要 |
An air filter (100) having opposing inlet and outlet surfaces (101, 102) defining an air flow direction (106) between the inlet and outlet surfaces and an open cell filter material (103) provided between the inlet and outlet surfaces (101, 102). The filter material (103) is compressed in a direction orthogonal to the air flow direction (106) towards the outlet surface (102) such that a porosity of the filter material (103) varies from a higher porosity along the inlet surface (101) to a lower porosity along the outlet surface (102). Preferably the air filter is for use in ventilation and temperature control applications, such as in electronic equipment, typically a telecommunications base station enclosure. Advantageously the air filter provides for a lower pressure drop for a longer time compared with a conventional filter, enabling the air filter to be used for longer before requiring replacement due to an increase in backpressure. |
