Modern, energy-efficient space heaters offer a convenient and cost-effective way to improve home and office comfort. Personal-size models can be an excellent choice for some situations. Larger versions can increase the warmth in a variety of living spaces, or they can be used as temporary heat in a garage or a workshop.
Space heaters are particularly useful when it’s impractical to expand an existing heating system to include additions or renovations, like when an extra bedroom or study has been added to the habitable space in a home.
With a wide choice of sizes, styles, and technologies available, it can be challenging to know which is the best energy-efficient space heater for a given situation. Just ahead are details about the types of space heaters available, including some of the best brands on the market.
- BEST OVERALL: Dr Infrared Heater Portable Space Heater, 1500-Watt
- BEST BANG FOR THE BUCK: Lasko 5775 Electric 1500W Ceramic Space Heater
- BEST PERSONAL: Brightown Mini Desk Heater, 400W Low Wattage
- BEST OIL-FILLED: PELONIS Oil Filled Radiator Heater
- BEST COMPACT: Vornado VH10 Vortex Heater with Adjustable Thermostat
- BEST MICATHERMIC: De’Longhi Mica Thermic Panel Heater
- BEST WI-FI: Atomi Smart WiFi Portable Tower Space Heater
- BEST GARAGE HEATER: Mr. Heater F274800 MH18B, Portable Propane Heater
What to Consider When Choosing the Best Energy-Efficient Space Heater
While kerosene and propane space heaters do exist, challenges with fumes and dangerous fuels mean the majority of space heaters safely used in the home are electric. Even narrowing the choices to electric-powered heaters still leaves a vast range of space heaters to choose from. It’s important to look at a number of key elements.
Before looking at the different types of heaters, it’s worth thinking about the way heat is produced. While there are radiant and micathermic heaters, most space heaters use convection to heat the air and maintain constant warmth whether there are people in the room or not.
- Oil-filled radiators are perhaps the oldest kind of electric space heater. Generally designed for medium to large rooms, they are quite bulky and usually have wheels to aid mobility. They provide some radiant heat while mainly heating the air.
- Ceramic space heaters are probably the most popular type and come in an enormous variety. Usually either box- or tower-shaped, they are light enough to be moved around easily and powerful enough for larger than average-size rooms. Forced-air (sometimes called bladeless) versions of ceramic heaters can help spread warmth around a room more quickly and evenly.
- Infrared space heaters use radiant heat. These types of heaters don’t warm the air, but rather they warm the people or objects within the space. They work much faster than convection heaters, and don’t waste energy heating a room that’s unattended. However, they work in a direct path, or “line of sight,” so they’re only at maximum efficiency when there’s nothing between the people and the heater. This is seldom a problem if people sit in a lounge situation, but more cluttered or busy areas can be challenging. However, infrared space heaters of 1,500 watts and greater draw a lot of current and could trip 15-amp breakers. A 20-amp breaker is advised, or a dedicated 15-amp circuit.
- Micathermic space heaters, available as panel heaters and similar in design to oil-filled models, contain a stone (mica) heating element that produces electromagnetic waves when heated. In effect, they produce both convection and radiant heat. While highly efficient, choice is currently somewhat limited.
Room Size and Heating Capacity
Space heaters are made in a wide variety of sizes and power options, so there’s something for just about every situation. Heat output is measured in watts (W), and general guidance is that 10 watts per square foot (sq. ft.) is needed to maintain a comfortable warmth. Therefore, a 100-square-foot room would require a 1,000-watt space heater.
Desktop models are around 200 to 400 watts, which can be very good for direct heat or modest personal spaces like a home office. The most common heat output in space heaters is 1,500 watts, which is sufficient for a 10- by 15-foot room. Heaters of 2,000 watts and upward are available, but large electric models may need to be hardwired.
Space heaters aren’t usually a replacement for central heating, but they can offer excellent efficiency and make big savings if they are only needed to heat a room or two. This can often be the case as the seasons change, when some parts of the house are cooler than others.
Additional energy efficiency comes by way of features on the space heaters themselves. Thermostats and adjustable heat settings allow increased control so energy isn’t wasted. Sleep or auto-off timers can be set to turn the heater off after a preset period, though most do not provide for an automatic “on” setting.
Smartphone apps allow access from anywhere. Control via Wi-Fi offers an increasingly large array of features, like remote turning on of the device so rooms can be warm when people return from school or work. There’s also the possibility of voice activation via smart-home systems like Alexa and Google Assistant. Allowing the user greater control provides the opportunity to maximize energy efficiency.
Some space heaters become warm to the touch, so care needs to be taken if there are children and animals around. Fabrics and soft furnishings also need to be spaced away from the heater. It may be worth looking for cool-touch housings as an additional way to prevent accidents.
Overload protection should be provided to protect against overheating. Most space heaters also have tilt or tip protection so the unit will turn itself off if it falls or is knocked over. All space heaters that meet current U.S. Department of Energy safety standards have a UL (Underwriters Laboratory) sticker.
Propane and kerosene space heaters give off poisonous carbon monoxide gas which can collect in unventilated rooms and presents a serious health hazard. Models for indoor use have a sensor that checks oxygen levels and turns the heater off if they are exceeded.
Few of the best energy-efficient space heaters could be described as particularly loud, though the noise levels do vary. The culprit is almost always the fan. Oil-filled and micathermic models have no fan, nor do most infrared models. While they might make a little noise when first heating up, these are very quiet during normal operation.
Ceramic space heaters generally have some kind of blower, and forced air models make a feature of it. This can cause them to be noisier on high settings. Few manufacturers provide decibel ratings. While most models are not intrusive, the heaters with louder powerful blowers may not be best for bedroom use.
Tips for Using an Energy-Efficient Space Heater
Regardless of the type of space heater chosen, optimum efficiency will always come from making sure it’s the right size for the chosen area. If it will be moved from room to room, then the largest room size should be used or it will struggle to provide sufficient warmth. On the other hand there is no point in over-sizing. Achieving the most heat value for the cost to run it will come from being as accurate as possible. If there are two very different size rooms, consider buying two heaters.
- Read the manual carefully to build a thorough understanding of all the features available and how to maximize the efficiency of the space heater.
- Space heaters are best when used in individual rooms, so keep doors closed as much as practical to prevent heat escaping.
- Even if the exterior of the unit is relatively cool, keep a minimum safe space of 3 feet between the space heater and any fabric or furniture. Check the owner’s manual to see if the manufacturer recommends a larger gap.
- If it is intended for bedroom use, check whether it is safe to leave it on during the night.
Never run power cords under carpets where damage can occur that might go unnoticed.
Our Top Picks
Now that you have a better understanding of the main features to consider when searching for a new space heater, it’s time to start shopping. The following are some of the best that meet many of the above criteria and one of these may be exactly what you need. Organized by category, this list helps make it easy to find the best energy-efficient space heater for particular situations.
This Dr Infrared model takes the number one spot for its combination of fast, efficient heating, safety, and portability. The headline figure of 1,500-watt of radiant heat is produced using two technologies: an infrared quartz tube that produces virtually instantaneous warmth, and positive temperature coefficient (ptc) heaters that offer outstanding durability and low-energy consumption.
Unlike many radiant heaters, it incorporates a fan to distribute the warmth more quickly, though it’s very quiet at just 39 decibels. Various temperature and mode functions are available via a handheld remote, and it includes a 12-hour auto-off timer. At just 16 inches tall, this unobtrusive space heater produces remarkable performance for its size. It weighs 24 pounds so it’s easy to move around, is safe to touch, and has tip-over and overheating protection.
The 1,500-watt Lasko is another heater that uses ceramic technology and combines oscillating action with a blower for effective heating around the home or the office. As with most space heaters of this kind, the exterior stays cool to the touch and there’s overload and tip-over protection to prevent accidents.
There are two power settings: 900 and 1,500 watts. A thermostat offers six preset temperatures, and there’s a built-in timer with a maximum duration of 7 hours. The functions on offer are fewer than some other models and there’s no remote control, but this is a perfectly adequate heater at a very competitive price for many shoppers.
The 400-watt mini space heater from Brightown is an efficient solution for heating small personal spaces. It can sit on a desktop or a table and uses ceramic technology so the exterior stays cool to the touch. It shares the same safety standards as larger models with both tip-over and overload protection. Controls are basic with just an on/off switch and an LED light to indicate when the unit is on.
While the manufacturer suggests it can warm areas of up to 100 square feet, that may be a little optimistic. It is most efficient in the same area as someone is working or studying, rather than as a room heater. At around 40 decibels it’s not the quietest of space heaters, but that sound level is little more than a background hum. Along with the very small size comes a very low price.
Oil-filled radiators aren’t as popular as they once were, but the 1,500-watt Pelonis has numerous features that warrant a closer look. Not the least of these is its competitive price and its wide range of features. There’s a programmable thermostat, a 10-hour timer, and an eco mode that steps down from 1,500 to 900 watts once the desired temperature is reached. Everything is controlled via remote. Tip-over and overheat protection are included.
Oil-filled radiators are virtually silent once warmed up, but they can take half an hour to heat a room thoroughly. This should be balanced against the fact that the oil continues to provide heat for some time after the unit is turned off. Managed properly, oil-filled radiators offer similar energy efficiency to other heat technologies. Though heavier than some models at 16 pounds, its wheels and a handle make it easy to move around.
The 1,500-watt Vornado VH10 is designed to be compact and easily portable while still having the power to provide ample heat for small- to medium-size rooms. The ceramic heating elements combine with a special vortex fan, providing a spiral of air that circulates quickly for comfortable warmth without unpleasant hot spots.
There are two heat settings, 750 and 1,500 watts, plus an adjustable thermostat. There is no timer or remote. The case remains cool and there is both overload and tip-over protection. A convenient carry handle helps move it from place to place and an integrated cord wrap keeps everything tidy when not in use.
De’Longhi’s stylish and slim 1,500-watt panel heater uses mica technology which produces a combination of around 80 percent convection and 20 percent radiant heat. This not only makes it very energy efficient, but it can be effective over larger areas. The manufacturer claims this model can warm up to 300 square feet.
Controls are manual rather than by remote control. There are two power settings (750- and 1,500-watt), thermostatic control, and a useful anti-freeze setting. Safety is covered by the usual tip-over and overheating protection.
The De’Longhi mica space heater can be used with or without wheels, or it can be wall-mounted (brackets included). It’s not completely silent, but even at full power, it is barely audible.
The 1,500-watt Atomi tower space heater offers energy-efficient ceramic technology with high, low, or eco power settings; a variable thermostat; timer; and the standard safety features expected on any modern space heater. What sets it apart is Wi-Fi control.
Using the smartphone app, control is available from virtually anywhere. The power mode can be changed and the temperature can be altered in 1-degree increments. There’s also a countdown timer with 1-hour increments, and both daily and weekly schedules can be set for turning the heater on and off. Should the unit get tipped over, it will send a phone alert. Many functions can also be voice activated using Alexa or Google Assistant.
The convenience and control offered by Wi-Fi connectivity might be expected to come with a premium price tag, yet the Atomi remains an excellent value.
Electric space heaters are great when insulation levels are high, but garages and workshops often have drafty areas that ruin their efficiency. The answer is a propane model like this one from Mr. Heater.
Propane space heaters are rated by BTUs (British Thermal Units) rather than watts. This Mr. Heater model provides warmth for spaces up to 450 square feet. Low, medium, and high heat settings compensate for varying outdoor conditions. Like electric space heaters, it has tip-over protection. It also shuts down if the pilot light goes out or if oxygen levels are reduced, so there’s no danger from carbon monoxide.
The unit produces a live flame, so care has to be taken if children are around or flammable materials/chemicals are present. A regulator and a 20-pound propane tank need to be purchased separately. Even so, in the right environment this is one of the best energy-efficient space heaters available.
FAQs About Energy-Efficient Space Heaters
The sections above tackled the technical aspects of energy-efficient space heaters and then provided some of the best real-world examples. This should prove invaluable when choosing one to buy. However, this is a complex subject, and there are a number of additional questions that crop up frequently. Answers to some of these popular questions are below.
Q. How can I tell if a space heater is energy efficient?
Unfortunately there are no recognized standards. A UL or ETL listing is sometimes quoted, but this ensures the space heater meets current safety standards rather than certifying efficiency. The U.S. Department of Energy website says it’s important to choose the right size heater for the room (don’t oversize) and recommends space heaters with a thermostat so the room isn’t overheated.
Q. What type of space heater is most energy efficient?
It’s a difficult question to answer because numerous factors have an impact. Strictly speaking, infrared is probably the most efficient, but not necessarily the right choice. It’s important to consider all the factors above in order to find the best energy-efficient space heater for your particular needs.
Q. How much does it cost to run a 1,500-watt heater for 24 hours?
Utility company charges, room size, and level of insulation all have an impact, but the best 1,500-watt energy efficient space heaters cost around $7 to $9 to operate for 24 hours.
Q. What is more energy efficient: a space heater or central heat?
Central heat is more efficient if the desire is to keep the whole house at a constant temperature for weeks at a time. Space heaters are more efficient in three ways:
- Heating personal spaces.
- Heating rooms that were added after the original central heat was installed.
- Boosting the heat in one or more areas when you don’t want to turn the heat up in the entire house.
Q. What type of space heater uses the least electricity?
Electricity consumption is calculated in kilowatts per hour (kW/hr). A kilowatt is 1,000 watts. In general, consumption relates directly to the wattage of the device, so you’ll save money if you can turn it down. The space heaters that use the least electricity are 200- to 400-watt personal heaters, but they provide insufficient warmth for family rooms.