Energy Saving Myths That Cost You Money, Plus Winter and Summer Tips That Work

Energy saving myths spread because they sound sensible, and some of them make your bills higher. This guide tests the most common ones against the U.S. Department of Energy’s Energy Saver Guide and ENERGY STAR data, explains what to do instead, and ends with practical tips for winter and summer.

Quick Quiz: Myth or Fact?

Pick an answer for each one. Your score appears at the end.

The Energy Saving Myths, One by One

Myth 1: Closing vents in unused rooms saves energy

It feels logical to heat or cool fewer rooms. But a central system is sized and balanced for the whole house. Closing registers raises pressure in the ducts, which pushes more air out through duct leaks and can make the system work harder or less efficiently. The DOE guide lists blocked registers among the airflow problems to fix, not as a way to save. Instead: keep registers open, seal duct leaks, and close the door of a room you don’t use if your home has good returns. For real room-by-room control, a zoned system or a ductless unit is the right tool.

Myth 2: Ceiling fans cool a room

Fans cool people by moving air over your skin. They don’t lower the room temperature. The DOE guide says a ceiling fan lets you raise the thermostat about 4°F with no loss of comfort, and to turn fans off when you leave the room. Instead: use the fan to raise the AC setting, and switch it off in empty rooms.

Myth 3: Keeping a constant temperature always saves energy

For furnaces and AC, the opposite is usually true. Your home loses heat more slowly when it’s cooler inside, so a lower setting while you sleep or are away saves energy. The DOE guide says you can save as much as 10% a year on heating and cooling by turning the thermostat back 7–10°F for 8 hours a day.

The heat pump exception: the same guide warns heat pump owners not to set back manually if it makes the backup electric resistance heat come on, and to use a thermostat designed for heat pumps. Big morning recoveries can trigger expensive strip heat. Small setbacks with a heat-pump-ready thermostat, or none, are safer.

Myth 4: Cranking the thermostat heats or cools faster

Most systems deliver heat or cooling at one speed. Setting 85°F instead of 70°F doesn’t warm the room faster; it just runs longer and overshoots. With a heat pump, a big jump can also bring on the backup heat. Instead: set the temperature you want and wait.

Myth 5: Washing dishes by hand saves energy

According to ENERGY STAR, using a certified dishwasher instead of washing by hand can cut utility bills by about $220 a year, mainly from hot water. Instead: run full loads and skip the pre-rinse.

Myth 6: “Off” means off

Many electronics keep drawing power when switched off or in standby. The DOE guide says this could add an extra 5–10% to a monthly utility bill. Instead: put the TV, console and speakers on a power strip you switch off, or unplug things you rarely use. Measure your own always-on load with a plug-in meter and enter it here:

Myth 7: Space heaters always save money

A space heater can make sense to warm one room for a short time. But electric resistance heat is expensive per unit of heat, so heating several rooms this way can cost more than your central system, especially if you have a heat pump. Safety first: plug space heaters directly into a wall outlet, never into an extension cord, power strip or smart plug, and keep them away from anything that can burn.

Myth 8: A programmable thermostat saves energy by itself

It only saves if it’s programmed, and if the schedule matches your life. Many are left on “hold.” Instead: set a schedule once, check it each season, and choose a heat-pump-compatible model if you have a heat pump.

Myth 9: Hotter water is better

The DOE guide recommends setting your water heater to 120°F, a temperature considered safe for most people. Higher settings waste energy and raise the risk of scalding. Check your tank’s manual before you change it.

Seasonal Energy Saving Tips

Winter

• Thermostat: set it as low as is comfortable, and lower it at night or when you’re out (heat pumps: see Myth 3).
• Sun: open curtains on sunny south-facing windows during the day and close them at night.
• Fans: the DOE guide suggests reversing ceiling fans to run clockwise in winter, so they push warm air down from the ceiling.
• Drafts: add weatherstripping to doors and caulk small gaps; use a draft stopper at the bottom of drafty doors.

Summer

• Thermostat: set it as high as is comfortable, and higher when you’re out. A fan lets you go about 4°F higher with the same comfort, per the DOE.
• Sun: close blinds or curtains on windows that get direct sun.
• Fans: counterclockwise in summer, and off when nobody is in the room.
• Heat-making chores: run the oven, dryer and dishwasher in the morning or evening, and use the microwave or grill outside on hot days.

Every season

• Check the air filter regularly and replace it as the maker recommends.
• Keep the water heater at 120°F.
• Switch off always-on electronics you don’t need.

Frequently Asked Questions

What are the most common energy saving myths?

Closing vents to save energy, leaving fans on in empty rooms, cranking the thermostat to heat faster, and believing that “off” electronics use no power.

Should I set back my heat pump at night?

Only a little, and only with a thermostat designed for heat pumps. The DOE warns against manual setbacks that make the backup electric heat come on.

Do LED lights wear out if I switch them on and off?

Switching LEDs off when you leave a room is the right habit. Frequent switching was a concern with some older fluorescent lights, not with LEDs.

Do power strips save energy?

A strip you actually switch off can cut standby power from electronics. Never use one for a space heater.