Fan (air blowers) tests
Fans are flow machines used to force vapors and gases. They are commonly used in air conditioning, cooling, dust removal, drying and many other installations. A distinction is made between radial and axial fans. This division results from their construction and is related to the direction of the medium flow through the rotor. Centrifugal fans draw in air axially and force it radially, while axial fans draw in and force air in the axial direction.
Axial fans are used when higher capacities are required, while centrifugal fans are used when greater damming is required.
- Measurements of the actual fan flow,
- Determination of fan pressure,
- Determining the operating characteristics of the fan,
- A set of tests to assess the compliance of products with the LVD directive,
- Electrical safety tests (mark B).
Depending on the amount of damming ΔPc obtained, fans can be divided into:
- low pressure – ΔPc 720 [Pa],
- medium pressure – 720 [Pa] ΔPc 3600 [Pa],
- high pressure – 3600 [Pa] ΔPc 30000 [Pa].
There are other criteria for the division of fans related to:
- The method of installation: suction, suction-pressure, pressure;
- application: e.g. explosion proof, roofing, for pneumatic transport;
- number of rotors: e.g. single-stage, multi-stage;
- method of suction of the medium: one-sided, two-sided.
The basic parameters of the fan, which characterize its operation, are efficiency, damming up, drive power demand, useful power and efficiency.
The fan efficiency is the volume flow of the medium forced through the device, while the damming is defined as the pressure difference between the total pressure at the outlet and the total pressure at the inlet. The increase in total pressure results from the increase in the energy transferred to the medium through the fan impeller. The effective power value is calculated from the product of the efficiency and the total damming and the correction factor taking into account the gas compressibility. The total efficiency of a fan is the ratio of useful power to shaft power.
The subject of the fan test is to determine its characteristics.
The characteristic shows the internal operating conditions of the fan and is the dependence of pressure on the volume flow. For a given fan and for each speed n, there is a curve that can be determined experimentally.
The knowledge of the characteristics is necessary for the proper selection of the fan for specific applications, as well as for the assessment of its correct operation.
COCH laboratory offers its customers the following fan tests:
- Performance measurement,
- Determination of static pressure,
- Determining the work characteristics,
- Useful power determination,
- Total efficiency determination.
Refrigeration R&D Centre „COCH” in Cracow
Juliusza Lea 116,
- mgr inż. Dorota Niedojadło
- mgr inż. Bogdan Szczepański
+48 12 637 08 57
+48 667 600 635
+48 503 021 131