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Running a space heater overnight increases the risk of fire. If the unit is left unattended or placed too close to flammable materials, such as curtains or bedding, it can ignite and lead to a devastating fire.
Absolutely. The US Department of Energy records about 25,000 house fires every year that are linked to a space heater fire. Many result in trips to the emergency room, with more than 300 fatalities each year. Property damage from these fires can be devastating, requiring extensive professional fire damage restoration.
Always turn off the heater when you leave the room. Extended use of heaters can make them break down internally, and they could catch fire. Plus, you waste energy when the space heater is keeping an empty room warm. To be on the safe side, look for a space heater that has automatic shutoff features.
Carbon Monoxide Risk: Gas-powered space heaters can produce carbon monoxide, a colorless, odorless gas that can be deadly in high concentrations. Proper ventilation is essential when using these heaters.
The duration for which you can leave a space heater running depends on the time of day and your specific needs. During the Day: It's safe to leave your heater on for 6-8 hours if you're in the room. If you're busy or moving between rooms, consider using a timer to automatically shut it off after a few hours.
Fires are one of the biggest risks associated with leaving electric heaters on all night. If an electric heater has frayed wiring or malfunctions, then there is a high chance of it igniting. Electric heaters also make the air in the room really dry by conducting a lot of heat.
Oil filled radiator space heaters are some of the safest on the market. 1500W is all the juice an outlet will provide (Roughly 5,000 btus).
Space heaters can take anywhere from 750 watts to 3,000 watts to operate. Large space heaters take immense amounts of energy to run. However, those are most likely used only in commercial and industrial settings. The average residential space heater has two main heat settings, low and high.
Most use 1,500 watts when on the highest heat setting, which costs about $2 per 8-hour day or over $50 a month based on the average cost of electricity nationally (local costs vary).
Portable heaters can cause fires if they are placed too close to combustible materials, such as drapes, furniture or bedding, so make sure to place them at least three feet away from these materials.
It's a Fire Hazard
Leaving your electric heater on all day is also a fire hazard. If you are not home to monitor the heater, it could overheat and start a fire.
One of the most common ways a space heater can cause a fire is by tipping over. Other ways are overheating, or being placed too close to flammable items like curtains. Portable space heaters can get very hot and ignite nearby objects, by either tipping over or being in close proximity to these objects.
Space heaters must have an automatic safety switch (tip-over switch) that turns the unit off if it is tipped over. Space heaters must have a thermostatic control which ensures that the unit will turn itself off and pre vent overheating or creating an electrical hazard.
Oil-filled heaters are very less likely to cause you any trouble when you leave them on overnight. These radiators have a high boiling point which helps the internal pressure of the oil stays constant. They don't have any moving parts, so you won't have to face any type of noise and sleep interruption.
Recommended Usage Times. During the Day: It's generally safe to run your space heater for 6 to 8 hours during the day while you're home and active.
Con: Fire and Burn Risk
The National Fire Protection Association warns that space heaters account for more than 40% of all home heating-related fires. Space heaters are also responsible for most fire-related deaths during winter, and they account for thousands of burn-related injuries each year.
On average, you can expect to pay about 20 cents per hour to run a typical space heater that's 1,500 watts and can heat a standard room such as a home office or bedroom.
Electric heaters of any type are unsafe to leave running overnight because they carry a significant amount of risk. If a space heater falls over or becomes too hot from running for too long of a period of time, that can lead to a fast-moving fire that occurs while you are asleep and cannot act fast enough.
"Buying a space heater for every room would increase the electricity bill more than if you had just bumped up the thermostat," Mikelann Scerbo, research manager for the Alliance to Save Energy, told Save on Energy.
“No, it's absolutely not safe to use a space heater at night,” states Glenn Gault, CEO at Gault Heating & Cooling. “It's not even safe to leave your space heater running when you leave a room for just a few minutes.
What is the safest heater to leave on overnight? While it's not recommended to leave any space heater on if you're not monitoring it, oil-filled, radiant space heaters are considered safer than ceramic convection (hot air) types, according to Roberson. Both of these options are safer than open-coil heaters.
Never leave the space heater unattended. Turn it off when you are leaving the room.
This can “cause headaches, fatigue and just not feeling right”, Cowl says. Meanwhile, warm spaces can cause your heart rate to decrease and make you feel less energetic, Durant explains. Heated air is also dry, which can lead to dehydration.