Night Setback is a scheduled temperature adjustment that reduces heating setpoints by 5-15°F (or raises cooling setpoints equivalently) during unoccupied nighttime hours to conserve energy. This simple yet effective strategy can reduce building heating energy by 10-15% with minimal comfort impact during occupied periods.
Implementation Standards
ASHRAE guidelines recommend setback temperatures of 62-66°F for winter nighttime periods in commercial buildings. Residential applications typically use 5-10°F reductions. Setback duration should align with occupancy patterns, commonly 8-12 hours nightly. Modern thermostats and building management systems automate setback scheduling without occupant adjustment, with override capabilities for unexpected occupancy.
Effectiveness and Considerations
Night setback delivers greatest savings in buildings with poor insulation or cold climates experiencing 10-20 degree temperature differences between day and night outdoor conditions. Rebound heating upon reoccupancy consumes additional energy but remains offset by nighttime savings. Buildings with continuous processes, sensitive equipment, or high humidity control requirements may require reduced setback ranges to maintain product quality and equipment protection.