Energy Efficiency of a Fan-Motor Assembly

What is the rate of energy supply from the fan-motor assembly to the room?

a) 0.50 hp

b) 0.325 hp

c) 0.4875 hp

d) 0.08125 hp

Final answer: The rate of energy supply from the fan-motor assembly to the room on a hot summer day, driven by a 0.50-hp fan with a 65 percent efficient motor, is 574 Watts.

Rate of Energy Supply from Fan-Motor Assembly

The rate of energy supply from the fan-motor assembly to the room is 574 Watts. This calculation takes into account the efficiency of the motor and the power of the fan.

When analyzing the energy efficiency of a fan-motor assembly, it is crucial to consider the effectiveness of the motor in converting electrical energy into mechanical energy. In this scenario, the motor powering the fan is 65% efficient, meaning that only 65% of the electrical energy is converted to mechanical energy, while the remaining 35% is dissipated as heat.

The power of the fan is given as 0.50 horsepower, which needs to be converted to watts for consistent units. One horsepower is equivalent to 746 watts, so 0.50 hp is equal to 373 watts. Since the motor is 65% efficient, the electrical power input can be calculated by dividing the mechanical power output by the efficiency percentage. Therefore, 373 watts divided by 0.65 results in approximately 574 watts of electrical power input.

The rate of energy supply from the fan-motor assembly to the room is determined by the electrical power input. Apart from circulating air, the fan-motor assembly also contributes to the heat content of the room by dissipating the 35% of electrical energy that is not converted into mechanical energy. Therefore, the rate of energy supply from the fan-motor assembly to the room is 574 watts.

Understanding the energy efficiency of appliances and equipment is essential in optimizing energy usage and reducing energy costs. By evaluating the efficiency of motors and calculating the energy supply rates to different spaces, individuals and organizations can make informed decisions to enhance energy conservation practices.