Mechanical upgrades save energy at Vance Published Oct. 24, 2012 By Airman 1st Class Frank Casciotta 71st Flying Training Wing Public Affairs VANCE AIR FORCE BASE, Okla. -- Dens Mechanical, contractors based in Enid, Okla., started work Sept. 9 on improving the heating, ventilation and air-conditioning systems in 17 facilities on base. The improvements will save the base $25,000 a year in energy costs. "We are doing a lot of things that aren't visible, like replacing older fan motors with more efficient ones," said Glenda Watkins, chief of design and energy manager for Civil Engineering at Vance. "We are also putting in variable frequency drives that make the systems more energy efficient." The drives have sensors and controls that are linked to the demand placed on the air handler. When temperatures don't match what they are suppose to be, the drives receive a signal to slow down, or speed up the motors. Without the sensors the motors just turn on and off. "We are also installing programmable thermostats," said Watkins. "With these, we will be able to set the buildings to 68 degree winter standard during the duty day. After hours, the thermostats can lower the temperature when no one is using the buildings, which will save energy." Programmable thermostats are excellent for home use as well. People apply the same principles and set their air-conditioning to what they feel comfortable with while they are home, and have the system shut off while they are at work, said Watkins.