Heatypes of heating systems ting your home accounts for nearly 30% of the average American household’s annual energy bill. See our heating system efficiency guide for more ways to reduce your heating bills. Setting your thermostat correctly — and using it intelligently — is one of the simplest ways to cut that number significantly. heating system maintenance best time to replace a furnaceThe most energy-efficient thermostat setting in winter is 68°F when you’re home and awake, 65°F while sleeping, and 58°F when you’re away for more than four hours.
What Is the Most Energy-Efficient Thermostat Setting in Winter?
The U.S. Department of Energy recommends setting your thermostat to 68°F during waking hours in winter. This strikes the right balance between comfort and efficiency. Every degree above 68°F can increase your heating bill by 3–5%.
The 68°F recommendation applies to daytime hours when household members are active and awake. At this setting, most homes maintain a comfortable baseline without overworking the furnace. The key is to dress appropriately — wearing a sweater or light layers indoors lets you stay comfortable at 68°F without reaching for the thermostat.
A programmable or smart thermostat is essential for efficiency. Without one, you’re either heating an empty house or waking up to a cold home. Smart thermostats can handle these transitions automatically and can generate 10–15% annual savings on heating costs by optimizing when and how much your system runs.
What Temperature Should You Set Your Thermostat When Sleeping?
You should set your thermostat to 65°F while sleeping. This is cool enough to promote restful sleep — research consistently shows that cooler room temperatures (60–67°F) improve sleep quality — yet warm enough that you won’t wake up shivering.
For households with infants or elderly members, slightly higher settings (67–68°F) may be more appropriate. The AARP recommends that elderly individuals keep indoor temperatures above 65°F, as older adults are more susceptible to hypothermia and have a reduced ability to sense cold.
If you have a smart thermostat, many models include a “sleep” or “night” mode that automatically adjusts the temperature based on your schedule — typically lowering by 2–3 degrees in the evening and raising it again 30–60 minutes before your alarm.
| Situation | Recommended Setting |
|---|---|
| Healthy adults | 60–67°F |
| Households with elderly | 65–68°F |
| Households with infants | 67–68°F |
| Pets at home | 65–70°F depending on pet |
Should You Lower the Thermostat When You’re Away?
You should lower your thermostat by 7–10°F when you’re away for more than four hours. This is one of the easiest ways to reduce heating costs without sacrificing comfort. The DOE estimates you can save up to 10% per year by setting your thermostat back 7–10°F for eight hours a day.
The four-hour threshold is important because it takes most furnaces 20–40 minutes to recover a 7–10°F setback. Shorter absences don’t give the system enough time to benefit from the setback before you return. Longer absences — a full workday, a weekend trip — offer maximum savings.
- Away 1–4 hours: Minimal savings; consider a 2–3°F setback
- Away 4–8 hours (typical workday): 7–10°F setback
- Away 8+ hours: 10–12°F setback is safe for most homes
- Away for multiple days: Set to 55–58°F (protect pipes, keep home above minimum)
One important caveat: if you have pipes that run through exterior walls or unconditioned spaces, don’t set the thermostat below 55°F even when away, as this creates a risk of frozen pipes during extreme cold snaps.
What Is the Ideal Humidity Level Indoors in Winter?
The ideal indoor humidity level in winter is 30–50%, with 40–45% being the sweet spot. During winter, indoor humidity often drops well below 30% due to heating dry outdoor air — which causes uncomfortable symptoms like static electricity, dry skin, scratchy throat, and irritated sinuses.
Most HVAC professionals recommend keeping relative humidity between 30–50% to avoid both the problems of low humidity (discomfort, wood shrinkage, increased static) and the risks of high humidity (condensation on windows, mold growth, dust mite proliferation).
A whole-home humidifier integrated with your HVAC system is the most effective solution, costing $300–$600 installed. Portable room humidifiers are a lower-cost alternative ($30–$150) but only address the room they’re in.
- Static shocks when touching metal objects
- Dry, itchy skin
- Wood furniture or flooring developing cracks
- Increased cold symptom frequency
- Condensation only on interior window glass (not between panes — that indicates seal failure)
- Condensation on windows that doesn’t evaporate
- Musty odor in basements or crawlspaces
- Mold or mildew visible on walls or ceilings
- Peeling wallpaper or bubbling paint
Frequently Asked Questions
What is the most energy-efficient thermostat setting?
The most efficient setting is 68°F during the day, 65°F at night, and 58°F when away for more than four hours. A smart thermostat can automate these settings and typically pays for itself within 1–3 years.
Do smart thermostats really save money?
Yes. Studies show smart thermostats save 10–15% on heaheat pumps ting bills annually. Models from Nest, ecobee, and Honeywell learn your schedule and preferences, automatically adjusting temperature to maximize efficiency without sacrificing comfort. For homes with heat pumps, smart thermostats are particularly valuable for optimizing the heat pump’s variable-speed operation.
Does turning the thermostat up higher heat my home faster?
No. Furnaces produce heat at a fixed rate regardless of thermostat setting. Raising the setting from 68°F to 75°F won’t heat your home faster — it will just keep heating past your desired temperature, wasting energy. Set it to the temperature you actually want. For electric heating systems, see our electric baseboard heater cost guide to understand how your heating type affects efficiency.
How do I prevent frozen pipes when I’m away?
Keep your thermostat set no lower than 55°F when away, even for extended periods. Open cabinet doors under sinks to allow warm air to circulate around exposed pipes. Consider pipe insulation for pipes in exterior walls.
What is a Manual J calculation and why does it matter?
A Manual J calculation determines your home’s precise heating and cooling load based on square footage, insulation, windows, orientation, and local climate. A properly sized furnace prevents both short-cycling (oversized) and insufficient heating (undersized), maximizing efficiency and comfort.
