How to check the capacity of ventilation fans

Why measure fan capacity?

● If fan capacity is impaired ventilation will be inadequate and

bird performance may be affected.

● Measuring air speed through the fan or measuring fan revolutions per

minute (RPM) will determine whether or not fans are working correctly

and are in line with manufacturers’ specifications.

Procedure for measuring fan capacity

Step 1– Open all air inlets and doors fully.

Step 2– If fan blades are plastic a reflective sticker will need to be placed approximately 5 – 7 cm (2 – 3 in) from the tip of the blade.

Step 3– Turn on the fan to be tested. All fans should be tested individually and at full speed.

Step 4– Holding the meter still 0.6 – 1.0 m (2 – 3 ft) away from the fan and at a slight angle point the laser at the sticker or directly at one blade if the blades are reflective / metal, until the reading on the tachometer becomes constant. Note If the fan has reflective / metal blades the recording on the tachometer must be divided by the number of blades the fan has. The RPM should be within the manufacturer’s guidelines or the guidelines set by an independent testing facility.

Step 5– Compare fan RPM with manufacturers’ specifications.