Why do you need a space heater?
Although space heaters generally shouldn’t be used to heat an entire building, they are a great way to supplement the warmth in specific rooms. Perhaps there’s an area of your home that has noticeably poorer heat distribution.
Or maybe you want to save money by spot-heating a room (or yourself!) instead of wasting energy by filling the entire space with hot air or pumping heat into a room with no one in it. Maybe your office is too cold and you want a small, personal heater to keep at your desk.
Generating heat can require significant wattage, though, and there are a few situations space heaters are not suited for—we cover those in our section on space-heater care, maintenance, and safety.
Small space heaters are typically used when the main heating system is inadequate or when central heating is too costly to install or operate. In some cases, small space heaters can be less expensive to use if you only want to heat one room or supplement inadequate heating in one room.
They can also boost the temperature of rooms used by individuals who are sensitive to cold, especially elderly persons, without overheating your entire home.
Space heater capacities generally range between 10,000 Btu and 40,000 Btu per hour and commonly run on electricity, propane, natural gas, and kerosene (see wood and pellet heating for information on wood and pellet stoves).
Although most space heaters work by convection (the circulation of air in a room), some rely on radiant heating. Radiant heaters emit infrared radiation that directly heats objects and people within their line of sight, and are a more efficient choice when you will be in a room for only a few hours and can stay within the line of sight of the heater.
They can also be more efficient when you will be using a room for a short period because they save energy by directly heating the occupant of the room and the occupant’s immediate surroundings rather than the whole room.
If you do think you may need a new heater, don’t wait for the cold weather to hit. Retailers usually stock space heaters seasonally, so prices and availability can fluctuate over the colder months.
What makes an energy efficient space heater?
Three types of space heater are considered energy efficient.
In the guide below, we discuss the differences in these heater types.
The key question is which is the most efficient for your purposes. The Guide will help you decide.
Immediate heat. Best for warming people directly in front of the heater. A few have fans.
Slower to heat. They’re portable, so are the best type for moving from room to room. Most have fans.
Slowest to heat. Best for longer heating of an entire room. The oil stores heat so iy continues to give off the heat after turning off. Quiet because they don’t have fans.
How we picked the best space heaters
We’ve updated this guide to build on our knowledge of and experience with the features that set a great
space heater apart from the rest. We start by researching all of the new space heaters released in a given year, along with popular competitors, whether or not we’ve previously tested them. Our research has led us to focus on two prominent types: compact electric heaters with fans and oil-filled radiators.
Most portable heaters we’ve tested in the past do a fine job of emitting heat, but after living with and using these heaters over time, we’ve discovered some very specific differences. Some heaters that heat well are infuriatingly difficult to clean, have nonsensical interfaces, or sound like wasps.
Others are easy to clean, intuitive to use, and silent, in addition to being effective heaters. So we took careful notes on what it was like to rely on and work alongside these heaters. We also factored in customer reviews, especially those from people who’ve owned a particular space heater for an extended period of time.
We pored over space heater reviews on Amazon, Walmart, and Home Depot, hunting for any patterns of defects or longevity issues.
With all this in mind, we prioritized the following features and performance criteria:
Adequate safety features
Space heaters can be dangerous—according to the National Fire Protection Association, space heaters accounted for 44% of home-heating fires from 2012 to 2016, and home-heating equipment (which also includes things like water heaters and fireplaces) accounted for 15% of all total house fires in that period.
When space heaters are the cause of those heating equipment fires, the fires are likely to result in death (86% of the time) or injury (76% of the time). One caveat: The NFPA’s definition of “space heater” also includes wood stoves.
All this led us to look for models that offered significant safety features, such as overheat protection (which automatically shuts the unit off if it begins to overheat) or tip-over kill switches (which automatically power down the heater if it tips over).
To confirm the reliability of these claims, we focused our search on products from companies that had been recognized by an independent safety testing laboratory, such as Intertek (whose seal often appears as “ETL”) or UL (Underwriters Laboratories). Safety features are an important aspect to consider when buying the best energy efficient space heater.
A 1,500-watt output
Most space heaters meet this requirement, regardless of size or type. Since watts measure power, a higher wattage results in higher heat output. Lower-wattage models—typically maxing out at 750 watts—have become increasingly popular in recent years as more people rely on them for personal portable heating in places like offices and shared housing, according to John Mayer, associate category manager for the Home Comfort team at De’Longhi.
While we’ve looked into these lower-wattage models before, we never found one that actually looked efficient and affordable enough for us to test until 2020.
Ability to heat up quickly
The sooner a space heater can warm a room, the better. Oil-filled radiators take more than an hour to reach maximum temperatures, whereas most ceramic room heaters start pumping out hot air almost immediately. However, it must also have overheat protection to prevent unwanted things from happening. An overheat protection can be good additional features.
Some of these portable heaters make enough noise that we’ve found ourselves talking over the heater, which is unpleasant. And any noise a space heater does emit, no matter how quietly, will ideally be a steady hum—no clicking or erratic whirrs. We specifically searched for models rated under 60 decibels, or about the same volume as a normal conversation.
A (relatively) cool exterior
Any space heater that is too hot to the touch is a safety risk, and that risk increases with the temperature. Most have plastic housings that won’t even reach 90 degrees Fahrenheit, but their front grilles can get hotter. We docked any model whose grille got consistently hotter than 160 degrees Fahrenheit, the point at which one second of contact burns the skin.
Most heaters have a thermostat and at least two heat settings, generally marked as high (1,500 watts) and low (750 watts). The thermostat manages the heat output, allowing you to find a middle ground between the heat settings.
After years of testing analogue controls, we have found they are more durable and intuitive on average, although digital controls are catching up.
Compact size: An electric heater should be small enough to work well without taking up too much space, as well as to store easily in a closet in the off-season.
While most people aren’t buying space heaters strictly as aesthetic decor for their homes, we still considered their appearance. Few of them are truly beautiful, but many are outright hideous. You’ll be living with them for months at a time in highly visible parts of your home, and we think you may as well have something nice to look at.
A carrying handle
You need to be able to move an in-use or recently turned-off heater without burning your hands.
A fan-only option: A heater with a fan-only option can conveniently double as a fan in warmer months.
How Efficient Is Electric Heat?
There are two ways to get efficiency with an electric heater: Buy the best energy efficient space heater and use it in an efficient manner. This guide discusses both parts of the equation – The heater you choose and how you use it.
Let’s start with electricity: Just how efficient is it?
“Electric space heaters are 100% efficient.”
That’s a statement made by manufacturers of electric heaters and by most sellers.
And the statement is 100% accurate – sort of.
What it means is that 100% of the electricity entering the space heater is turned into heat. That’s true for all types of electric space heaters.
But there is a lot more to that story.
And here it is as told by the DOE: “Electric resistance heating is 100% energy efficient in the sense that all the incoming electric energy is converted to heat. However, most electricity is produced from coal, gas, or oil generators that convert only about 30% of the fuel’s energy into electricity. Because of electricity generation and transmission losses, electric heat is often more expensive than heat produced [by] natural gas, propane, and oil.
Did you know? Many studies clearly show that electricity is the most expensive fuel for heating. Costs vary by region of the country.Should you abandon the idea of buying a space heater?
Not yet. When used properly, a space heater can be reasonably efficient. That’s what we talk about next.
Using an Electric Heater Efficiently
This is about the second part of the equation mentioned above – using a space heater in an efficient way.
But using one electric heater, maybe two, as part of an overall plan to reduce energy use is possible with these guidelines:
1. Turn Down the Central Heat & Use a Space heater for One Room at a Time
This is really the best way to use a space heater.
Turn down the central thermostat by 5-10 degrees.
Then, turn on a space heater in the room you’re occupying. Common scenarios include:
A bedroom at night
A living room, TV or kitchen in the evening – wherever people gather
A home office during the day or evening
A bathroom that gets a lot of use in the morning as people get ready for the day
Pro Tip: If you’re using three or more space heaters at a time, you are probably wasting energy. Turning up the central heating system makes more sense.
2. Use for Supplemental Heat Only
Obviously, your electric bills would skyrocket if you heat your entire home with space heaters. Depending on your climate and the size of your home, it might require 5 to 10 of them.
Instead, electric heaters should be used to aid a central heat system – a gas furnace, heat pump or boiler are the most common types.
Often, one or two rooms don’t get as much heat as the others – a bedroom distant from the furnace, for example. That’s where a space heater can effectively boost the room’s heat to a comfortable level.
Pro Tip: If you have three or more rooms that aren’t adequately heated, you should contact an HVAC professional to determine the reason. It could be an undersized furnace or heat pump or it could be a ductwork or zoning issue.
3. Emergency Heat
If your main source of heat fails, space heaters can keep your home livable and prevent freezing pipes until the heat pump or furnace is repaired.
Pro Tip:If power outages in freezing weather are common where you live, an electric heater won’t help, obviously, unless you have a gas generator to produce electricity to run it.
A better source of emergency heat in freezing weather is an indoor-safe portable propane heater. We recommend the highly-rated Mr. Heater F274830 MH18BRV Big Buddy Grey Indoor-Safe Portable Propane Heater
It delivers immediate heat and a lot of it. The three heat settings are 4000 BTU, 9000 BTU and 18000 BTU.
4. Choose a Space Heater with Efficiency Features
Many electric heaters are built for energy efficiency. Look for these features:
#1 Multiple Heat Settings
Most with two settings have a low/750W and a high/1500W option. A few are 900W/1500W or 1000W/1500W.
#2 Eco (economy/ecological) Mode
This function chooses the right heat setting for you.
Let’s say you have a heater with 750W & 1500W settings.
You set the heater thermostat to 72F and turn on Eco mode.
The heater will heat with 1500W to get the room to 72F. Once there, it will switch to 750W to keep it there. If the temperature dips, it will switch back to 1500W, and so forth.
Do you or others in your household forget to turn off the space heater when you leave home?
Do you wake up with the bedroom too warm due to the heater?
Those situations waste energy and raise energy costs.
A timer is a solution.
Timers are available in 1-8, 1-10 and 1-12 hours depending on the model.
#4 Digital Thermostat
Some heaters have dial-type thermostats without actual temperature settings. Those kinds take trial and error to figure out where to set the dial to get the heat level you want.
A digital thermostat is more accurate, which keeps you comfortable without risk of making the room too warm.
Pro Tip: Even digital thermostats can be a little tricky. Most turn off before the room temperature reaches the thermostat setpoint. This is because the thermostat is inside the unit rather than across the room on a wall.
In short, you might find that if you want it to be 72F in the room, you might need to set the thermostat to 74F or higher.
We recommend getting a room thermometer to know exactly what the air temperature is in the room. Then, you’ll be able to determine the right thermostat setting to get the air temp you want. Make sure it has overheat protection.
#5 WiFi Electric Heater
This is the ultimate way to control your space heater from anywhere. Forget to turn it off when leaving for work? Just use the app to do it.
Want to warm up a room before you arrive home? Turn on the heater remotely 30 minutes before you arrive!
#6 Person Sensor
A few electric space heaters have infrared sensors. They stay on when they detect a person in front of them, often within 6 feet. When the person leaves for more than two minutes, the heater shuts off. It turns back on when the person returns. You can have an energy efficient space.
Top 9 Most Energy Efficient Space Heaters in 2021
1. Radiant Electric Heaters Duraflame 9HM8101-O142 Portable Infrared Heater
This is the top-rated heater in its class. It remains cool to the touch and won’t dry out the air like some electric heaters. Casters make it easy to roll. It has an overheat sensor on the plug – a unique safety feature. A portable space heater can be set up almost anywhere.
This product comes in an all-in-one package with a digital thermostat, timer, and a remote.
The product is built with furniture quality wood, which is definitely a must buy for those who are looking for a long lasting heater with an aesthetically pleasing look. However, there are no variants to the colour that this product comes in. Consumers will only have the choice of an oak coloured heater. Consumers who opt for this choice would be advised to ensure that this oak coloured heater would go well with the interior design of their home
The best place to use these types of heaters is in your living spaces where it can be directed to areas that are most commonly occupied, like a couch or a bed.
2. Duraflame 5HM8000-O142 Portable Electric Infrared Quartz Oscillating Tower Heater
An oscillating feature is nice on an infrared heater because the motion sweeps the room with heating energy. This unit comes in light oak, dark oak and cherry. For you to have an energy efficient space. This unit is a portable space heater that can be arranged anywhere in your house.
This small and easy to use heater comes with an oscillation mode which enables the heat to travel to a wider radius. Furthermore, there is also a choice for consumers to switch to various fan modes to adjust the heat to your liking.
Unlike the first choice, this heater comes in 3 different colours which allows consumers the freedom of mixing and matching their furniture for aesthetic purposes.
Unlike box heaters, the only con of having a tower heater is that these heaters will tip easier, therefore making this choice a possible hazard option. Consumers are advised to take precautionary steps before purchasing this product.
The oscillation mode makes it ideal for rooms that are occupied by several people. Rooms that are large in size will benefit from this choice as well, due to the larger heating radius.
3. Heat Storm Phoenix Floor to Wall Infrared Space Heater with Attachable Feet
Heaters on the floor make a room cluttered and can be a trip/fall hazard. This one has attachable feet, but most who buy it mount it on the wall. Two colors plus a WiFi version. This is an energy efficient space heater.
This space heater comes in two power settings, which is the 750W setting and the 1500W heat setting. The heater comes with a kit, which allows it to be easily mounted to the ground or on the wall, depending on your preferences.
The space heater also comes with a digital thermostat which allows consumers to easily adjust the temperature of the heater.
This choice is best for offices which are generally smaller in size as it could be easily mounted on to a wall. Furthermore, having it mounted on the wall would also be beneficial for households with kids. Kids will not be able to reach for the heater, thus avoiding a possible health hazard.
4. Ceramic Electric Heaters – Honeywell Slim Ceramic Tower Heater
Save floor space with this top-rated tower heater that is light and portable. Two heat settings for small or large spaces. It oscillates and is a good value.
This portable tower heater also comes with two power settings, which is 750W and 1500W. This tower heater also has a timer that allows users to set the duration for heating. After the set duration, the heater will automatically turn itself off.
Although tower heaters are generally easily tipped, this product has a tip-over shutoff function which help prevent any fire hazards.
This product is best used for crowded rooms where floor space is limited. Consumers who are looking to buy one for their offices, smaller bedrooms or living rooms should definitely opt for this choice.
5. Comfort Zone Oscillating Space Heater w/ ECO Mode
This highly rated space heater has all the features for efficiency and comfort. Economy (Eco) mode automatically reduces the heat setting from high to low when the thermostat setpoint is reached. 70-degree oscillation. It’s an energy efficient space heaters as it comes with an eco mode.
There is an 8-hour timer for those who want their heaters to automatically turn off. This heater is also light and portable which is very useful for those who travel alot.
This is best used in large rooms where people are spread out or any room with limited floor space.
6. Pro Breeze 1500W Mini Ceramic Space Heater
It’s rare to find a space heater this inexpensive and this highly rated. It has two heat settings and a fan-only mode for cooling and a “white noise” for sleeping or studying. Light and portable.
Comes in two different power settings, which is 750W and 1500W. This is a really compact heater which is best used in smaller rooms.
However, the thermostat for this heater is not digital and the fan can be extremely loud at times.
This is a perfect budget option for students or people who need a temporary heater. This is also an extremely great option for those who travel a lot as it is extremely light.
7. Oil-filled Electric Heaters – Pelonis Portable Oil-Filled Radiator Space Heater
Efficiency features include a programmable thermostat, 10-hour timer and Eco mode which runs at 1500W until the thermostat setting is met and then switches to 900W. This is an energy-efficient space heater as it comes with eco mode.
Consumers can set it between 65 to 85F with the thermostat. This heater comes with a remote and a timer which will automatically switch itself off after a set duration.
Consumers have reviewed that this product heats slowly, and has recommended that consumers should turn the heater on 1 hour prior to their bedtime to ensure the best heating experience.
8. NewAir Electric Oil-Filled Space Heater
This unit is nearly identical to the Pelonis model. Different brand, but just as highly rated. Creates 5,100 BTUs per hour when fully warmed up. It’s an energy efficient space heaters and has an eco mode.
This heater comes with a digital thermostat which allows consumers to set between 65F to 85F. This heater also has two power options, which is the 900W and 1500W.
The only con to this heater is that it heats up really slowly.
9. Trustech 700W Portable Mini Radiator Oil Heater
Less wattage means less energy consumption and lower utility costs. This 700W space heater is compact and weighs just 8lbs. This product also comes with a tip-over switch.
This is an overall good and efficient product as less energy is used for this heater. This compact sized heater will also not burn easily, which is great for consumers who have safety concerns when owning a heater.
The only con to this heater is the manual thermostat. The manual thermostat does not display an accurate temperature.
These types of heaters are best used in smaller sized rooms such as a dorm room. Students can easily fit this under their desk.
Match Heater Size to Room Size
Remember that electric heaters are designed to provide supplemental heat. Tip-over switch
In general, you need about 10 watts per square foot to raise an insulated room’s temperature by 5-10 degrees.
- 500 watts: Up to 50 square feet (5×10, 7×7) – Bathroom, cubicle, door room, desktop and similar. Check out Top Small Space Heaters in our website.
- 750 watts: Up to 75 square feet (7.5×10, 8×9) – Bathroom, small office or small bedroom.
- 1000 watts: Up to 100 square feet (10×10, 12×8) – Large bathroom, office, small bedroom, galley kitchen.
- 1500 watts: Up to 150 square feet (10×15, 12×12) – Bedroom, office, kitchen, den.
Pro Tip: For raising the temperature by 11-15 degrees, you’ll need 15-20 watts per square foot. Electric space heaters really aren’t designed to provide more heat than that except in emergency heating situations.
On the other hand, using a heater or a heat setting that is too large for the room will waste heat.
Is One Type of Electric Heater More Efficient?
OK, this is where other sites confuse the issue to make it seem like one kind uses less energy than others. We clarify it instead.
A 750-watt electric heater uses 750 watts of power per hour regardless of whether it is a radiant/infrared, ceramic, oil-filled, bare metal coil or other types.
Ditto for 1500-watt heaters of all types. They use twice the energy of a 750W heater and cost twice as much to operate.
And we already noted that space heaters are 100% efficient at turning electricity into heat.
So the answer is “No.” Space heater efficiency does not vary by the type of heater it is.
Near the top of the page, we said, “The key question is which is the most efficient for your purposes.”
Let’s explore in more detail the idea of how you plan to use the electric heater – that is, how you can use it efficiently to be energy efficient space heaters and still get the warming comfort you want.
Here are the three most popular electric space heater types with pros, cons and best uses.
Also called infrared heaters, they emit perfectly safe infrared rays that warm people and objects in their path. Immediately.
Pros: Turn on the heater, and feel the warmth as quickly as stepping out of the shade into the sunlight on a brisk autumn day. Remote control
Many of these heaters are housed in attractive, furniture-quality cabinets. They are cool to the touch because infrared doesn’t make the heating element and housing super-hot. This makes them kid-friendly and pet-friendly too. Those without fans are very quiet.
Cons: Most radiant heaters have price tags that are above average for all-electric heaters.
Where to Use: These heaters are best for heating people directly in front of the heater. They are ideal for locations where people are fairly stationary – the TV room, a bedroom or office where the unit can be aimed at people.
These units create heat by the element getting hot and heating the air around it. That air is usually dispersed with a fan. Some don’t have fans. They heat a room as the heat moves further from the source. This is known as convection heating.
Pros: They heat up a small space pretty quickly. Most are light and portable, so are the best type for moving from room to room. The air in the room stays warm longer than when heating with infrared/radiant once the heater is turned off.
Cons: Some are cheap and fail quickly. Shop for a highly rated model like those in our Best Electric Heater list at the top of the page.
Where to Use: These are ideal for short-term use in a general area. For example, make a chilly bathroom or kitchen warm while using it before you leave for work. Or use it for an hour or two in the evening while watching TV or using the internet. Remote control
A radiator-style tank is filled with oil. An element inside the tank heats the oil, and the heat radiates out from the tank. The oil remains warm when the heater is turned off, and will continue to give off heat for 30-60 minutes depending on heater size and room temperature.
Pros: Heats after turning off. Quiet because they don’t have fans.
Cons: They heat up slowly, so won’t give you instant heat. Remote control
Where to use: These electric heaters are best for longer heating of an entire room – Bedrooms are most common, but they are used in living space and offices too.
A Heat Pump Is Not Electric Heat
Sometimes heat pumps are called electric heaters, and that causes confusion.
Yes, they are fueled by electricity. But there is one major difference. The electricity is not used to create heat. Heat pumps don’t make heat. They capture heat in one place and pump it to another.
Refrigerant pumped by the compressor flows between an indoor coil and an outdoor coil. Coils are like radiators. In winter, the refrigerant captures heat outdoors and brings it inside. In summer, a valve is reversed, and the refrigerant captures heat indoors and pumps it outside to be released through the outdoor coil.
For whole-house heating, a heat pump is far more efficient than space heaters.
There are many energy efficient space heater available in the market right now of which choosing the best energy efficient space heater might look pointless however as a good consumer we must always be smart as to choose the most energy efficient space heater and use it efficiently and optimally to ensure that we get the most efficiency and get the bang for the buck.
An energy efficient space heaters should have the characteristics that we mentioned in this guide such as overheat protection among other things. These characteristics is what makes a specific model truly the most energy efficient space heater. The best energy efficient space heaters are also not rigid to only one specific heater type as there are three major heater type of the best energy efficient heaters available for example the ceramic space heater.
You should also not forget that in order for a heater to be energy efficient our habits and lifestyle also play a major role. Although there are many amazing features such as remote control or tip over switch to help the unit to be energy efficient. You should also take into play several usage habits to make the most of your best energy efficient space heater. The choice is all yours.