Final answer:
Using a programmable thermostat's setback feature can significantly reduce energy consumption in a temporarily unoccupied building, resulting in cost savings and lower environmental impact. option c is the correct answer.
Step-by-step explanation:
The use of a programmable thermostat's setback feature can significantly reduce energy consumption in a temporarily unoccupied building. This feature allows the thermostat to automatically raise or lower the temperature during certain periods, such as when no one is home. By lowering the temperature in the winter or raising it in the summer, the HVAC system doesn't need to work as hard to maintain the desired temperature, resulting in less energy usage.
For example, during the winter, if the setback feature is used to lower the temperature by a few degrees when no one is home, the HVAC system will consume less energy as it doesn't need to constantly heat the space to the set temperature. Similarly, in the summer, if the setback feature is used to raise the temperature, the system will use less energy to cool the space. Overall, using the setback feature on a programmable thermostat can reduce energy consumption by five to fifteen percent, helping to save on energy costs and reduce environmental impact.