Power Factor in a Ceiling Fan and What does it mean?

The amount of power supplied to an electrical appliance is usually not reflected in the output power given. This can better be understood by recognizing the types of power defined in electrical studies- true power, reactive power and apparent power. True power is the power which is dissipated in form of resistances and creates heat.

But due to the presence of reactive components i.e. inductances and capacitances in electrical appliances, reactive power comes into play. Reactive power is the power which is not dissipated in the form of heat but is stored in the capacitor or inductor. Thus, this power is not made use of and hence contributes nothing to output of appliances.

This is where the power factor comes into play. Since a ceiling fan employs a capacitor its input power is both a combination of true power and reactive power. To determine the actual power consumed by the fan, it is necessary to take account of its power factor.

The Power Factor

The power factor is the value of the actual (or true) power used by an appliance divided by the expected (or apparent) power–the latter being the product of the line voltage (V) and current (I).

PF = true power/(Vx I)

Values of power factor can be anything between 0 and 1, a value of one implies that all the electricity drawn by a load is being consumed. Examples of appliances that have a power factor of one are electric-resistance heaters and incandescent bulbs . Taking a 60W light bulb as an example, the wattage represents the actual power consumed by the bulb.

Due to some current storing devices or electrical component like the capacitor or the inductor the power factor of a few devices is less than one and these devices include the normal florescent lamps, the electronic devices in regular use. It also includes the electric motor.

Actual significance of power factor

To define through a simpler analogy would be identify resistive loads as a cup of water and reactive loads as a cup of coffee. In case of a glass of water you get what you see, there is no wastage of energy of any kind. However, in the case of reactive power, the cup of coffee is not just filled with coffee but with some froth too. This froth occupies volume but is not drinkable, yet you pay for it too. It is unavoidable as a nice of coffee cannot be imagined without its froth.

Thus, power factor determines how much of power you provide to the ceiling fan is being wasted as froth and how much of it is actually coffee. In order to get a more value for money you may install a coffee machine which generates lesser froth or a ceiling fan which has a decreased inductive load.

Fans being sold today are equipped with more energy efficient designs including BLDC motor for their operation. This ensures a power factor of greater than 90%. Thus, in order to save on your energy bills, power factor of the ceiling fan is one thing which you must consider. Check atomberg’s fans which are energy efficient as well as available at lower price.