Should You Leave Your Heating On Overnight When It's Very Cold in January? HVAC Pros Reveal What Will Protect Your Home from Costly Damage
No, it doesn't always mean eye-watering energy bills
Sleep experts often recommend a cooler bedroom for better sleep, but in the dead of winter, there is such a thing as too cool for comfort.
This begs the question: Should you leave your heating on overnight when it's very cold outside in January?
Should You Leave Your Heating On Overnight in January?
The short answer is yes, you should leave your heating on overnight in freezing weather.
Eli Zimmer, CEO, Luxaire HVAC Services, explains, 'A rule you should never follow is turning your heating system off completely at night. The idea behind this is that when you are sleeping, you don’t need temperatures to be as warm, plus you can save money.
'Those things are true, and you can accomplish them – but you shouldn’t turn off your heater completely at night to do so. This was more common back in the early-mid 20th century because central heating wasn’t as efficient as heating systems are today.'
While the perfect thermostat setting for better sleep is usually on the cooler end, Josh Mitchell, HVAC technician and owner of Air Conditioner Lab, explains, 'When it drops below 20° Fahrenheit outside, I tell people to leave the heat on overnight. Not just for comfort, but to avoid damage and stress on the system.'
Even if you are tucked up snug in bed using the hotel method to stay warm, allowing your property to become too cold can result in frozen pipes, dampness, and mold.
'Even if you're used to turning down the heat at night, you still want the indoor temperature to stay above 65°F,' Josh advises. 'For houses with older windows or plumbing along exterior walls, going below that invites frozen pipes. I've repaired frozen copper lines in kitchens where overnight temps inside hit the low 50s. Those repairs cost hundreds.'
Keeping your bedroom warm also prevents you from shivering in the night, or when you get up in the morning.
Although heating just the bed and not the whole house is one way to cut energy bills at a particularly expensive time of the year, Josh explains that the cost of potential repairs is a far scarier prospect than the small increase in running costs.
'Running the heat overnight at 66°F tends to use only about five to seven percent more energy than turning it off completely. But the tradeoff is worth it,' he says. 'The system does not need to work overtime to reheat the entire house in the morning, which can add 30 to 45 minutes of runtime on colder days. That’s when the extra wear and tear builds up.'
To help lower heating costs in winter, Josh suggests setting your nightly thermostat two to four degrees lower than your daily temperature. 'In homes with babies, the elderly, or anyone with breathing issues, I keep it at 68°F at the lowest. At night, your body temperature drops, and colder rooms can disrupt sleep or trigger wheezing for those who are sensitive,' he adds.
The World Health Organization advises the new heating standard of 68-70°F in the winter to reduce the risk of respiratory illnesses. It also helps reduce the winter risks to the elderly, infants, and chronically ill.
When our Head of Solved, Punteha van Terheyden, recently tested the new heating standard in her home for six weeks, she found illness frequency and duration of her household reduced, window condensation disappeared, and energy bills did not rise, despite the heating running overnight. This was because the heating cycles are shorter in a warmer house, and she had to also turn the bedrooms' radiators down, which meant less hot water was used.
If you are concerned about running the heating unnecessarily, you can invest in a smart thermostat, such as the Honeywell Home Smart Thermostat from Best Buy. These devices will turn the heating on only when your home drops below a set temperature, helping you to heat your home only when it needs it, thereby preventing energy wastage.
What to Shop
A smart thermostat can adjust the heating in your home according to the ambient temperature, maintaining a constant comfortable climate without having to run the heating constantly.
A heated blanket can help you to warm up your bed before turning in for the night, helping you get to sleep more easily. Always remember to turn the blanket off overnight, and never leave it running unattended.
Pipe insulating tape can help to protect exposed pipes from freezing temperatures. In very cold climates, you may also want to consider heated cables so that you are not having to run our heating on high constantly.
Window film adds an extra layer of thermal insulation to your home, limiting cold air transfer to make home heating more efficient.
If you have floor heating vents, consider heat deflectors to help push the heat directly into your room, rather than up cold walls. This can help to make heating more efficient, so that you can feel the benefit more quickly.
Indoor temperatures are not your only consideration in winter. You also need to keep tabs on indoor humidity to prevent mold and musty odors when we have our windows closed 99% of the time. This hydrometer and thermostat help you do just that, alerting you to dangerous levels to help you take quick action.
Meet the Experts
Eli is the director of operations of Luxaire HVAC Services. For over 32 years, businesses across Long Island have relied on Luxaire HVAC Services for expert commercial heating, cooling, and indoor air quality solutions. They specialize in servicing, repairing, and installing HVAC systems tailored to the unique demands of commercial facilities.
Air Conditioner Lab was founded by HVAC technician Josh in 2014 as a way for him to document his findings on home air conditioners and cooling methods.
Maintaining your heating is one of the most vital parts of successfully winterizing your home.
To conclude, Josh warns, 'Turning the heat off completely during cold snaps isn't worth the risk. You lose more by reheating cold drywall, floors, and air than you save. It's not just about the air temperature. It's about the whole house structure needing to warm back up again.'
