Fan electrical absorption.

Fan are positive displacement pumps so, keeping the RPM costant, volume of gas moved does not change with the volumic mass of the gas itself. On the other hand will vary the power required to the engine, of any type it is.

One of the most important parameters for calculate the absorbed power of a fan is the global efficiency, which depends on a lot of factors as the kind of construction, the RPM, the shape of the blades etc..
Choosing the right efficiency is possible to evaluate every kind of fan, both axial and centrifugal. Results will have a lot of correspondence with real values for a lot of aim also in the industrial system field.

Data input

Gas properties.

Select gas to be transported

Manual data Air (sea level) -40 gr C Air (sea level) -20 gr C Air (sea level) 0 gr C Air (sea level) 20 gr C Air (sea level) 50 gr C Air (sea level) 100 gr C Air (sea level) 200 gr C Air (sea level) 300 gr C Air (sea level) 400 gr C Air (sea level) 500 gr C Air (altitude 1000 m) -40 gr C Air (altitude 1000 m) -20 gr C Air (altitude 1000 m) 0 gr C Air (altitude 1000 m) 20 gr C Air (altitude 1000 m) 50 gr C Air (altitude 1000 m) 100 gr C Air (altitude 1000 m) 200 gr C Air (altitude 1000 m) 300 gr C Air (altitude 1000 m) 400 gr C Air (altitude 1000 m) 500 gr C

Gas density

kg/m³

Plant data.

Required gas flow

m³/h m³/sec

Total pressure required

mm H2O m H2O Pa

Fan

Manual data All types, maximum efficiency All types, medium efficiency All types, low efficiency All types, very low efficiency

Global efficiency

n

Optional electrical data (case with electric motor)

DC, AC single-phase

AC triphase

Direct current or alternating current single-phase

Tri-phase alternating current, Y or delta link

Supply voltage

V

Results.

Required power

W kW CV hp

Absorption

A

Notes.
Normally greater fan will have bigger efficiency than smaller one.

Generally:

• 50000 m³/h and above = maximum efficiency.
• 15000 m³/h = medium efficiency.
• 1000 m³/h = low efficiency.
• Small fan = very low fan.

Please remember that is difficult to find engines with installed power equal to the required power. Depending on type of motor, will be always a certain reserve of power needed to compensate not expected load variation.
Normally the most overestimated motors are the internal combustion type, on the contrary of the electric ones, they have better efficiency if not loaded at 100%.