Energy Consumption at the Wake Forest Gym
Currently in the Wake Forest gym, there are forty-eight pieces of cardio equipment. The usage of this equipment was tracked on Wednesday, March 28th, 2012, via the Miller Center gym website. Every thirty minutes the site is updated with available equipment. The following chart was composed based on the openings of equipment. The chart shows how many pieces of equipment were in use at a particular time. For the purposes of this paper, it will be assumed that these pieces of equipment were used for thirty minutes. It is important to note that not all times were recorded on the gym website. These rows are highlighted in the chart. In order to still be able to use the data, it was assumed that the same amount of equipment was used during the unrecorded time as the time slot before it. Below is the chart.
Now, the current energy usage of the machines will be calculated. Thirty-six of the cardio equipment pieces are self-powered. These include twenty-three elipticals, eleven bikes, and two stair steppers. Currently these pieces of equipment consume no energy when in use, but they do lose energy in the form of heat. This will be further explored in the “ReRev technology at Wake Forest” section of this paper. For now, only the inefficient pieces of equipment at Wake Forest are explored. These include ten treadmills and two stair masters.
Eight of the ten treadmills in the Wake Forest gym are Precor 956i treadmills. For the sake of estimating the energy use of treadmills, the wattage of the Precor 956i treadmills is used to determine the energy usage of all the treadmills. The wattage of a machine is equal to its volts multiplied by amps. A Precor 956i treadmill is 120 volts and twenty amps (956i Treadmill Specifications). The calculation for the wattage of the Precor 956i treadmill is below.
Watts = Volts x Amps
120 Volts x 20 Amps = 2400 Watts
Next the amount of hours equipment is used will be multiplied by the watts in order to get watt hours. For Wednesday, March 28, 2012, there were one-hundred and sixteen uses of treadmills for thirty minutes apiece. That is equal to fifty-eight hours worth of use. The watt hours are determined below.
Watt Hours = Wattage x Hours of Use
2400 Watts x 58 hours = 139,200 Wh = 139.2 kWh used on March 28, 2012 by treadmills
Based on the above calculation, it is believed that treadmills at the gym consume 139.2 kWh a day. However, since the gym is not open the same amount of hours each day this is not the case. A ratio is used to determine how many kilowatt hours are used on the days with different hours. The ratio is as follows.
On Wednesday the gym is open 16.5 hours and treadmills are used for a total of 58 hours, therefore, the ratio is as follows:
Eight of the ten treadmills in the Wake Forest gym are Precor 956i treadmills. For the sake of estimating the energy use of treadmills, the wattage of the Precor 956i treadmills is used to determine the energy usage of all the treadmills. The wattage of a machine is equal to its volts multiplied by amps. A Precor 956i treadmill is 120 volts and twenty amps (956i Treadmill Specifications). The calculation for the wattage of the Precor 956i treadmill is below.
Watts = Volts x Amps
120 Volts x 20 Amps = 2400 Watts
Next the amount of hours equipment is used will be multiplied by the watts in order to get watt hours. For Wednesday, March 28, 2012, there were one-hundred and sixteen uses of treadmills for thirty minutes apiece. That is equal to fifty-eight hours worth of use. The watt hours are determined below.
Watt Hours = Wattage x Hours of Use
2400 Watts x 58 hours = 139,200 Wh = 139.2 kWh used on March 28, 2012 by treadmills
Based on the above calculation, it is believed that treadmills at the gym consume 139.2 kWh a day. However, since the gym is not open the same amount of hours each day this is not the case. A ratio is used to determine how many kilowatt hours are used on the days with different hours. The ratio is as follows.
On Wednesday the gym is open 16.5 hours and treadmills are used for a total of 58 hours, therefore, the ratio is as follows:
The next chart uses ratios to determine the actual kWh consumption each day at the gym.
This same thinking is now applied to the stair masters. There are two stair masters in the Wake Forest gym. Each one uses fifty-five watts (StairMaster). The following chart shows consumption of energy in kilowatt hours based on the use from Wednesday, March 28, 2012.
Based the two energy consumption charts, the gym’s treadmills and stair masters consume about 808.6 kWh a week. It is important to note that this is just the energy consumption from equipment. This total does not include the energy needed to power lights, televisions, and fans in the gym.