Lowering the temperature while you sleep can reduce heating energy in many homes because the building loses less heat when the indoor-outdoor temperature difference is smaller. Savings depend on climate, insulation, system type, and recovery behavior; heat pumps and specialized systems may need a different strategy.
A moderate setback is usually more practical than an extreme change
You do not need to make the home very cold to save energy. A comfortable, safe setback can reduce heating demand without requiring the system to recover from a huge temperature difference in the morning.
Heating-system type can change the strategy
Some heat pumps may engage electric auxiliary heat during aggressive recovery, reducing the benefit of a large setback. Check the manufacturer or installer guidance for your specific system.
Do not sacrifice safe conditions for people or the home
Infants, older adults, pets, vulnerable plumbing, and moisture problems can limit how far a setback should go. The nighttime temperature still needs to be appropriate for occupants and the building.
Schedule recovery instead of making a large manual jump
A programmable thermostat can begin recovery before you wake. If you make a large manual increase every morning and the system uses auxiliary heat or runs for a long time, adjust the timing and setback size to find a better balance.
Sources
- U.S. Department of Energy — Energy Saver — Practical information on home heating, cooling, thermostats, and energy efficiency.