Is the yellow pedestal fan 30" round, adjustable height, yellow and pull chain?
This comes with a 2-speed pull chain switch.

Is a higher CFM or lower CFM more energy efficient?
The CFM is determined by the size and shape of the fan blade in conjunction with the RPM of the motor.  That being said, the actual energy efficiency would be determined by dividing the CFM by the energy being used to produce the CFM.

I am comparing a fan with a 1/2-HP motor producing 6700/cfm @ 1115/rpm and 9250/cfm @ 780/rpm with your Airmaster DJ-PF30-2SPJ-DC. Which is the more efficient?
The Airmaster DJ-PF30-2SPJ-DC uses a 1/3-HP motor and produces 6915/cfm @ 1115/rpm and 5000/cfm @ 780/rpm.  Based on the lower HP consuming 310-watts the 5000/cfm equates to 16.13/cfm per watt consumed. the fan with the 1/2-HP motor consumption is in the vicinity of 1130-watts, therefore the 9250/cfm equates to 8.19/cfm per watt consumed.  Obviously the more CFM per watt consumed is the more efficient, illustrating the Airmaster is the more efficient.

How do you know how many watts a motor uses?
On a single phase motor you multiply the motor rated amps x the motor voltage will determine the amount of watts used by a motor. and on a three phase motor you multiply the wattage by 1.73

What is meant by CFM?
CFM means cubic feet of air per minute. It is the measurement of airflow.