Are you fed up with the high utility bill during the cold weather season?

Then you need an energy efficient space heater.

When you spend significant time in one place, then there is no reason to warm your whole house through your central heating unit or HVAC.

When you want to warm up a living room, bedroom, bathroom, or outdoor patio, without using much power bill, you need a space heater. 

This guide contains all the information you need to know about energy efficient space heater. And our unbiased space heater reviews.

Quick Picks

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Dyson AM05 Hot + Cool Fan Heater

This heater has dual functionality of heating and cooling. The blade less design makes it safe to operate while it provides super efficient heating.

Best Overall

 Dr Infrared Heater Portable Space Heater

Super high energy efficient infrared heating perfect for any room or place. It has tip over and overheating protection. Heater produces very low noise which is suitable if you don't want to be distracted.

Best Value

Lasko CD08200 Bathroom Heaterw Mount AC

High quality ceramic heater which can be used in the bathroom or any place where you desire it to be. The automatic overheat protection makes it safe around kids and pets.

Most Efficient Space Heater

Our Top Pick

 Dr Infrared Heater Portable Space Heater

Dr Infrared Heater Portable Space Heater

Infrared Dr. Heater Portable Space Heater is our top pick for the most energy efficient space heater. The use of infrared technology makes it highly useful in converting electricity into heat.

It delivers 60% more heat than similar heating units. The automatic tip-over protection and overheat shut-off are a nice safety feature. It makes this unit to be safe to use indoors and outdoors.

Infrared heat does not dry off the air, which is essential to people who are sensitive to dryness. Best of all, it is tranquil and portable, which makes it ideal to use while at work or rest.

What is Space Heater?

A space heater is a small appliance which is used to heat small personal space. Space heaters are supplemental heating to your room, office, garage or any place which gets too cold to use in the winter season.

The space heater is not intended to heat your whole house but a small part of it. But if you live in a small size house or apartment, then you can also use it as your primary heating source during the cold weather.

You may also prefer to use space heaters when you want to keep the home temperature low but warm the particular area. 

The best space heaters are portable, easy to operate, and heat room efficiently without wasting energy. We will discuss all these factors individually later in this article. 

Most Efficient Space Heater Review

#1. Lasko Designer Series Ceramic Space Heater

Lasko Designer Series Ceramic Space Heater

Lasko ceramic space heater has a unique looking stylish design which looks very classy. It has a ceramic heating element and 3 settings of heating temperature.

Under the well-crafted body, it is powered by 1500 watts of power and oscillation, which is useful in heating up to 100 square feet.

Lasko has included an adjustable thermostat. It lets you choose temperature from 60 to 85 degree Fahrenheit. The temperature is easy to read with a bright LED temperature indicator.

The built-in timer can be programmed from 1 hour to 7 hours, which saves energy. This is good enough time to turn it on while you are at work or want to relax on the couch. You can program it in 1-hour intervals, and the heater will automatically turn off at the set time.

Safety is essential for any space heater, and overheating is one of the significant risks. The overheating of a device may cause fire or damage it.

Lasko has included the overheat protection module. It automatically turns off the heater if left on over an extended period.

The Lasko's ceramic-based hater keep the exterior cool to touch despite producing heat to warm the room. This is very helpful if you have kids or pets in your house.

Unlike other heaters, there is no assembly required as everything is already included in the box and ready to use.

For those who like style and design, this compact space heater comes with an attractive cream color and has crackle finish on the top. The low noise output makes it ideal to use in a bedroom or in an office. It comes with a limited 3-year manufacturer warranty and is one of the best electric heaters.

See More information on Lasko Designer Series Ceramic Space Heater


  • Stylish design
  • Digital thermostat
  • Overheat protection 
  • Remote control
  • Self-regulating ceramic element 


  • No tip-over switch
  • No moving wheel

#2. Infrared Dr. Heater Portable Space Heater

Infrared Dr. Heater Portable Space Heater

Dr. heater infrared portable space heater has a unique looking box design. When glanced over the first time, it looks like the robot from the 70s.

The heater uses a combination of the infrared Quartz tube and PTC thermal heating. This means you get the benefit of energy efficient infrared heat and the comfort of thermal heating to heat up the whole room.

Using infrared heating alone produces hot and cold spots. This is where Dr. Heater's infrared combined with thermal heating proves to be a well-thought-of heating unit.

It has three different power setting mode; automatic energy saving mode, low temperature (1000 watt), and high temperature (1500 watt).

The built-in 12-hour automatic shut off time is nice extra feature toward the safety of unit which prevents it from getting overheated.

The very adjustable thermostat allows you to set temperature from 50 to 86 degree Fahrenheit. Once you set the heat, the heater adjusts itself to maintain the desired temperature.

The backlit digital temperature display allows you to use the space heater in the dark or during sleep with lights turned off. This is convenient as no more guessing in the cold night about the temperature of the heater.

You can use the included remote to change the temperature, set up the timer, or power it on and off.

The noise of the heater is a factor when looking for a space heater as too much noise can become distracting and annoying.

This is where Dr. Infrared heater shines. Even though it has high power blower, it remains tranquil, and the noise level stays below 39 decibels.

The use of an infrared heater is quite comfortable as it does not make the air dry which many other space heaters do. But if you are sensitive to air dryness, then you can pick Dr. Infrared Heater with a humidifier model.

It is very portable and weighs just 24 lbs, which makes it easy to move around. The 72-inch long cord makes it easy to move around at different places without trying to hunt down another electrical outlet.

For your ease, it has attached wheel, which means you don’t have to lift it when moving as you can merely push it around.

The use of highly efficient blower makes this space heater deliver 60% more heat, which means saving in the electricity bill.

Overall the wooden casing design and highly visible temperature display make it versatile and the most energy efficient space heater.

See More information on Dr Infrared Heater Portable Space Heater


  • High energy efficient infrared heating
  • Tip-over and overheating protection
  • Very low noise
  • Digital thermostat
  • 12 hours automatic shut off time


  • Bit bulky to place on the table
  • Little expensive than other heaters

#3. DeLonghi Safe Heat Oil-Filled Radiator

DeLonghi Safe Heat Oil-Filled Radiator

DeLonghi Safe Heat space heater is an oil filled heater which saves energy and reduces the electricity bill. It provides swift and effective heating for a small to medium space.

The high powered 1500 watt means this oil filled space heater means a business. It can heat a room quickly with its proprietary ComfortTemp technology. It reduces energy use by self-maintaining optimal temperature and regulating power settings.

At the front of the heater, there is a mechanical temperature control dial which allows you to set your desired temperature.

The high-quality energy efficient oil inside the panel get it hot quickly. This means you can enjoy continuous, effective heating with a simple push of a button.

The maintenance-free design of the unit means there is no moving parts and nothing to replace. The oil inside the panel is permanently sealed, which means you don't have to worry about refilling the heater.

One common issue with any oil-based space heater is the odour. This generally happens on first-time use. If you don't want the lingering smell in your room, then you have to temper it before use.

To temper oil-based space heater, plug the unit outside of your house in a well-ventilated area. Set the temperature to high and turn the control dial all the way up to the highest temperature. Then leave it there for a couple of hours.

The tempering process will burn off the coating at the top of oil pipes. The protective coating prevents the rusting of the unit. But you only need to do it once, and after that, you can use it indoor without having any issue with odour.

We think this is something the manufacturer of oil-based space heater should do before they sell it to customers. But it is not something which may be an issue for most of the people.

The advantage of oil-based space heater is its long life and ability to keep heating the room even when it is powered off. This is useful if you live in an area where you don't have a reliable power source. Many people also use it during camping, where they use a generator to power the heater.

As a safety feature, the unit has automatic cut-off functionality, which shuts off the heater if it starts to get overheat. The attached wheels make it easier to roll it around different spots or bring it closer to you.

Overall, DeLonghi's Oil filled heater is an energy efficient space heater and is one of the best space heaters for a large room.

See More information on DeLonghi Safe Heat Oil-Filled Radiator


  • Three different heat setting
  • Comfort Temp setting saves up to 30% energy bill
  • Thermal slots prevent the surface from getting too hot 
  • Outstanding value for money 


  • Need for Tempering in the beginning
  • Limited heat setting

#4. Dyson Hot + Cool Fan Heater

Haier Serenity Series AC

This is a versatile space heater which can be used in both winter and summer season. This means you don't have to buy a new radiator for the summer season. The dual functionality of the heater allows you to change the setting with a simple, quick flip of a switch.

This heater has a blade less design, which means it is very safe to use around kids and pets. Dyson has invested a lot in the research to come up with Air Multiplier technology.

It works by amplifying the surrounding hot air and pushing it fast through specially designed interiors to maximize its long-range reach.

In hot summer days, the powerful airflow and air velocity quickly cool things down. This is all made possible with the use of high-powered energy efficient electric motor.

The inbuilt thermostat maintains the desired temperature without much intervention. The safety features include the automatic shut off on tipped over.

Many traditional heating elements get over more than 752 degrees Fahrenheit temperature while operating. It results in burning smell when dust falls over these elements. The elements in the Dyson space heater never exceed over 392-degree Fahrenheit, which produces no burning smell.

You can set up the temperature at the low range of 33 degrees to high range of 99 degrees Fahrenheit. This makes it work both in summer and winter.

The other extra feature we liked in this heater is the ability to tilt it on an angle. We find this convenient if you want hot or cold air to flow directly over to you.

Keep in mind that there is no compressor cooling, so it will not work as an air conditioner but will replace the generic fan.

Dyson comes with an infrared remote control which allows you to control the oscillation, air flow, temperature, and power with a push of a button.

The 2 years parts and labor warranty give you the peace of mind in case anything goes wrong. It weighs around 5 lbs, which makes it easier to move around.

See More information on Dyson Hot + Cool Fan Heater


  • Dual functionality of heating and cooling
  • Blade less design
  • Efficient heating 
  • 2 years limited part and labor warranty 


  • Pricier than other heaters
  • Not ideal for a large space

#5. Lasko Ceramic Tower Heater

Lasko Ceramic Tower Heater

Lasko ceramic tower heater is one of the best for heating large spaces. The self-regulating ceramic heater provides heat with a powerful energy efficient heating 1500 watt elements. It has a built-in safety feature which prevents overheating of the unit.

There are limited two heat settings. The low and high-temperature setting works in combination with oscillating of the unit in the desired direction.

The ceramic heating means it is energy efficient. The compact and curved design of the unit makes it very low profile. This means saving of space.

The conveniently located control buttons at the top allow you to turn it on and set the desired temperature with a simple push.

The wireless remote control allows you to manage power, oscillation, temperature, and the timer.

The automatic shut off timer protects the unit from getting overheated. Ceramic elements keep the exterior cool, which is helpful if you have kids or pets in the house.

The handle is at the back of the unit, which makes it easy to move around. The bright color-coded LED display makes it easy to know the temperature.

See More information on Lasko Ceramic Tower Heater


  • Ceramic unit keeps the temperature low
  • Simple temperature control setting
  • Overheating protection 
  • Large color-coded LED display 


  • Not ideal to heat large room
  • No automatic tip over switch

#6. Mr. Heater Buddy Propane Radiant Heater

Mr. Heater Buddy Propane Radiant Heater

Mr. Heater Buddy propane heater is energy efficient propane-based space heater. It is good to heat room up to 225 square feet. You can use Mr. Heater indoor or outdoor with its clean-burning propane gas.

The vital safety feature includes auto shut-off if tipped over or if it detects low oxygen level. This is important to prevent generating carbon monoxide when using indoor.

The carbon monoxide is a deadly gas which you can’t smell. It is generated when the fuel is burned with poor ventilation. Carbon monoxide causes lots of death every year. So, it is assuring that this heater detects carbon monoxide level when in use.

The propane-based heater is useful when you have an unreliable power source such as while camping or in case the power goes off in winter. The heater has two settings of 4,000 and 9,000 BTU range, which is technically low and high-temperature.

Since this is a propane heater, so you have to attach a gas cylinder for it to work. The conveniently located swivel regulator allows you to easily connect liquid propane cylinder from 1 lb to 20 lb cylinder.

The lower capacity 1 lb propane cylinder can be attached directly to the heating unit. To connect anything more than 1 lb to the heater you have to use optional hose and cylinder.

Operating this heater is very easy. To turn it on, you simply rotate the knob and push the piezo ignition button. We found this design to be useful as you don't have to hunt down matchbox or lighter to use it.

As a safety measure, the hot elements are guarded by wires, and the unit turns off if it falls down to prevent accidental fire.

We like the highly portable and secure design of the unit. The fold-down handle makes it easy to lift the unit when needed and fold it back for storage, which saves the space.

The unit does not have a thermostat, which means it can’t self-regulate the temperature, and you have to do it manually.

Mr. Heater comes with a 1-year limited warranty.

See More information on Mr. Heater Buddy Propane Radiant Heater


  • Indoor and outdoor use
  • Propane powered
  • Tip-over protection
  • Automatic shut off at low oxygen 


  • Lack of thermostat
  • Propane tank not included

#7. Lasko Bathroom Space Heater

Lasko Bathroom Space Heater

Lasko bathroom space heater is a versatile space heater which provides over 1500 watts of comforting heat. You can quickly set it up in a bathroom, small office, or bedroom.

It is rated as a bathroom heater, which means you can use in any room, including bathrooms. This is nice if you want to place it in the toilet if it gets too cold to use.

The 1500 watts power gives you the ability to heat up to 225 square foot room. The safety feature includes 1-hour auto power off. It means if you forget to turn off, then it will turn off itself after an hour.

The operation of this unit is very straightforward. As soon as you turn on the heater, the red light lit up at the front, which indicates that the heater is ready to use.

There are two heat settings (low and high). It is a very power efficient heater and starts producing heat as soon as it is turned on.

When you turn on the unit, you hear the audible beep letting you know that the heater is ready to use. We find it helpful if there is reduced visibility.

The specially designed ALCI safety plug makes it is safe to use in the bathroom. The unit uses a ceramic element to produce the heat, and a fan blows the hot air outside.

The small stable design allows it to put anywhere in the room. The low height design reduces the chance of accidental trip over. The heater automatically shuts off after 1 hour to prevent overheating. The use of ceramic makes the exterior cool to touch.

It weighs only 4 lbs. This makes it very portable, and you can place it wherever you need some heating. For example, you can put it on your desk or on the kitchen table if required.

The heater has a low and high-temperature setting, which will appeal to you if you want a simple operation. You don't have to fiddle with programming this heater.

The simple plug and play operation means even if you don't read the operating manual, you will be able to use it in no time. But we do recommend that you read the manual regardless to get information about the device and right way to operate.

The ALCI safety plug automatically turns off the unit if increased condensation in the bathroom. It increases the risk of short-circuiting the heater.

The condensation increases when you take a hot shower. As it produces lots of steam, but the cold temperature quickly turns the steam into water.

The unit is designed to turn off after an hour, if you want to use it longer than an hour, then you can choose low or high settings.

There is no automatic shutoff at those settings. You will have to do it manually.

All the controls are located at the top of the unit, which makes it easier to operate. You don’t have to bend to change the settings, which is useful if you place the heating unit on the floor.

You will like the simple design of this unit and white color blends with any room color. It is one of the best electric heaters in its category.

See More information on Lasko Bathroom Space Heater


  • High quality ceramic heater
  • Can be used in bathroom
  • Automatic overheat protection 
  • ALCI safety plug to use it in the bathroom 


  • No handle
  • No thermostat

#8. Vornado Vortex Heater

Vornado Vortex Heater

Vornado Vortex heater is a perfect indoor space heater which turns out to be super quiet. It provides excellent heating for a small to medium space.

The Vornado’s Vortex Action airflow system circulates warm, gentle spiraling heat through its angled exterior wire mesh. There are two temperature setting, low and high.

The low-temperature setting uses 750-watt power, and the high-temperature setting uses 1500 watt, which makes it be one of the best electric heaters.

If you want more control for heating, then the adjustable thermostat allows you to to pick your desired temperature.

You can control both the heat and fan speed individually as per your need. As a safety measure, the unit comes with an automatic shut off feature if it gets overheated. Moreover, the tip-off protection feature turns the unit off if it accidentally gets tipped over.

The controls are placed at the top of the unit, including easy to read digital display. The soft push button control makes it easier to operate the unit. The protective exterior design keeps the heater remain cool when it is touched.

The low noise fan circulates the air around the room so you can get the uniform temperature in the room. The Vornado Vortex heater comes with a 5-year satisfaction guarantee. It shows the confidence the manufacturer has in their product.

This is a lightweight unit, 4.8 lb, and has integrated carrying handle which you can use to move it around wherever you want. For safe storage and to reduce the tripping hazard from the cord, there is hidden cord storage. You can wrap the cable when not using the unit or wrap the excess wire.

See More information on Vornado Vortex Heater


  • Lightweight and compact design
  • Unique Vortex Action Air system
  • Fast and even heating to medium size room 
  • Quiet operating fan 


  • Limited temperature control option
  • Warranty only available in the US

#9. Delonghi Mica Panel Heater

Delonghi Mica Panel Heater

Delonghi Mica Panel heater comes with a 1500-watt power which gives the instant heat. Unlike other heaters which sometimes looks bulky, the Delonghi Mica Panel heater is a very thin, lightweight and functional portable heater.

The benefit of a panel heater is the increased flexibility of unit placement. You can keep it on the floor and move around with attached wheels, or you can mount it on the wall.

To keep the unit safe, it automatically shuts off if it falls over. This is useful if you are hanging it on the wall. The inbuilt thermal cut-off shut down the unit when it overheats. It reduces the risk of damaging the unit or causing a fire.

Micathermic technology allows this unit to be super slim. This well-designed unit makes it easier to remove the wheels and get the panel out to mount on the wall.

This makes it very efficient in the use of space. It may be particularly useful to people who have a small room or have kids or pets. The wall mounting prevents kids or pets, touching the heating unit.

There is no fan in a mica panel heater. This means it runs noiseless, which is helpful if you are putting it in an office or in a room where you don’t want fan noise.

The matte finish black design looks very stylish. This is the right choice space heater for those who like slim profile heater with all the safety features.

It comes with a safety feature such as thermal cut-off protection. The power indicator is located at a front. The anti-freeze setting on the unit prevents the freezing of pipes, which keeps the heater operational whenever needed.

For people with allergies, the Micathermic heater is an excellent choice. It uses the room’s natural air to circulate the heat rather than a fan, which moves dust and other small particles.

See More information on Delonghi Mica Panel Heater


  • Energy efficient space heater
  • Can be mount on the wall
  • Lightweight and portable
  • Automatic tip-over and thermal cut-off 


  • Not ideal to use in large space
  • Limited range

Types of Energy Efficient Space Heater

There are two types of energy efficient space heater. It is based on the type of fuel used to power the heater.

Petroleum Based Space Heater

The petroleum-based spaces heaters use oil, natural gas, kerosene, and gasoline to power up the heater. These are the most energy efficient space heater because the fuel burns entirely and the majority of the fuel gets converted to heat.

But the downside of petroleum-based space heater is that it produces smoke on burning fuel and requires proper ventilation. This reduces the portability of petroleum-based space heaters.

To use petroleum-based space heaters, you have to connect it directly with an exhaust vent or use it outdoor. These space heaters are more useful where it is hard to get electricity such as in RV or during camping.

The biggest annoyance with a petroleum-based space heater is it refuelling. As you have to keep your fuel topped up and then store it safely. 

Natural Gas Space Heater

The natural gas heater is convenient and most common in homes. It uses the gas supplied to the house, and many people use it as a primary heating source.

The natural gas space heaters are convenient to install. You can directly attach it to the natural gas coming into your house. But doing so reduces the portability of the space heater.

Propane Space Heater

The propane space heater uses propane gas to generate heat. It is more suitable to be used outdoors such as on patios.

Kerosene  Space Heater

Kerosene is a cheap fuel, but sometimes it is hard to find. Handling kerosene is smoother than a propane space heater. But we do not recommend it to use indoor due to lingering kerosene smell on its use.

The kerosene-based heater needs proper ventilation due to generating a risk of carbon monoxide.

Electricity Based Space Heater

Electricity based space heater is very portable and safe to use. But these are less energy efficient than the petroleum-based space heater.

The most significant advantage of electric space heater is its cleanliness as there is no smoke generated on its use. This makes it ideal to use indoor and large enclosed rooms.

You can also mount these electric heaters on a wall or a ceiling which makes it very portable and convenient to use. Most space heaters available for indoor use of electricity as a power source.

Following are conventional electricity-based space heaters.

Ceramic Space Heater

The ceramic space heater uses ceramic as a heating element. These are excellent grade positive temperature coefficient ceramic (PTC) material. It heats up when electricity passes through it.

The fan or oscillator blows room air through the ceramic which heats up the air as it passes. It provides very focused heat while it remains cool to touch.

This is useful if you have small kids or pets in your house as it reduces the chance of them getting burned.

The ceramics are very durable and last long. This makes ceramic-based space heater to last several winters without breaking down. 

Micathermic Space Heater

Micathermic space heater uses a mica and nickel alloy material in the space heater construction. It works by generating radiant and convection heating. The heat is generated and flows through the large Micathermic panels.

The Micathermic heater heats up quickly compared to conventional space heaters. Moreover, it doesn't overheat fast. This is important if you plan to use your space heater for a un-interrupted longer duration.

This makes the Micathermic space heater to be one of the most efficient space heaters which are very economical and safe to use. 

Radiant Heater

Radiant heaters are the most common types of a space heater. It provides very directional heat to the objects near it or in its path.

The electric coil or a quartz tube generates heat on the passage of electricity. This makes a radiant heater to take very less time to warm up and provides rapid heating. The only drawback is that it often gets hot outside, which increases the risk of burning.

The directional heating of radiant heater means that you have to sit very close to the radiator to get the heat. 

Infrared Space Heater

Infrared space heater uses the invisible light to heat the room. It is a type of radiant heater but more effective in warming a closed space area.

The infrared space heater is one of the most energy efficient space heater as it converts most of the electricity into heat.

The traditional heaters heat the room by making heat to disperse throughout the apartment, including ceilings. This waste a lot of heat, as the more significant the room size, the longer it takes to warm the space.

This is where the infrared space heater shines as it provides direct heat. Another advantage of using infrared space heater is that it does not remove the humidity from the air. This is a common problem with other heater types as it increases the dryness in the room on use.

Humidity is essential to keep our skin moist and reduces the irritation caused by the increased dryness. 

oil-filled space heater

Oil-Filled space heaters

Oil filled space heaters use special oil stored in specially designed sealed pipes. The oil does not get burned when heated. The oil is slow to heat but once heated, it provides the long term heat as oil takes time to cool down. 

There is no fan involved which makes oil-filled space heaters to produce virtually no noise. It is useful if you plan to place it in your office or bedroom where you want it to be quiet. 

How Space Heater Work

The space heater has three general processes:

  1. Heat generation
  2. Heat distribution, and
  3. Heat control

You can generate the heat either using electricity or using oil and fossils fuel. Many energy efficient space heaters use electricity to produce heat.

The electricity passes through a heating coil which resists the flow of power, and it generates the heat in this process.

In a second process, the heat gets distributed either through a fan or fanless. If the unit contains a fan, the cold air pass through the heat generating element which warms the air.

In a fanless unit, the cold air passes through the heating unit due to temperature difference and gets heat up.

The third process is heat control. It is essential as you don't want your space heater to get too hot, which could damage it. The space heaters have thermostats which regulate the temperature of the unit. 

Benefits of Space Heater

The space heater heats up quickly and can warm space in a brief time. This saves the money as you will not be using your central heating units to warm your whole house.

The limited and efficient use of a space heater makes you use less electricity and gas. You should use a space heater to heat a single room or area which complements the existing home heating unit.

Be aware that if you live in an area where the temperature drops significantly, the space heater may not be replacement of your home heating unit. 

But for moderate use, the space heating unit provides portability and convenience. 

How to Determine Which Space Heater to Use

Majority of people get confused when it comes to choosing the energy efficient space heater for their home. So follow this simple step when you are in the market to buy the space heater.

First, know that not all space heaters are the same. You have to pick the space heater, which is powerful enough to warm the area you plan to use, but it should not make the room too hot.

The technical specifications of space heaters depend on two factors: 

  1. The power measured in wattage, which refers to the electricity required to heat the space.
  2. The heat generating ability of the power source referred to as a British thermal unit (Btu).

The wattage is the most common specification you will find on the space heaters. Many residential space heaters have low heat and high heat settings. The low heat settings generally use 750 watts, whereas a high heat setting uses 1,500 watts.

The higher the watt means more heat generating capacity. But it will also consume more electricity.

Here is how to find out which power rating space heater you should buy.

Step 1: Find out the room size where you want to use the space heater. Using a measuring tape find out the length and width of the room.

Then multiply the length and width of the room. This will give you the area of the room.

Step 2: If you have an 8 Feet Ceiling

The wattage required = Area X 10

For ceiling higher than 8 Feet

The wattage required = Area x Height x 1.25


Let's imagine your room  is 20 feet by 20 feet in size,

The area becomes 400 sq. ft (20 feet x 20 feet).

If you have an 8-feet ceiling, then the space heater wattage required is

Area x 10
or 400 sq. ft x 10 = 4, 000 watts or 4 Kwt (Kilowatt)

For over 8 feet ceiling such as 9-feet, the wattage required is

4,500 watts (400 x 9 x 1.25), or 4.5 Kwt.

That is all you need to know to get the correct estimate of the power rating of the space heater to warm up your room efficiently. 

If you don't want to do all those calculations then use the below reference chart to find out the power rating of space heater you need based on the room size. 

Room Sq. ft

Heater Wattage

























So, what will happen if you don't use the correct rating space heater?

Using a space heater with a lower power rating than required means you have to keep it on for the longer duration. And it may not even provide you comfortable warmth due to low heat.

But using a space heater with a higher power rating than required means your room will be too hot and you will be wasting electricity.

Note: Some space heater also marks the unit in Btu/hr. You can convert the Btu to watts by dividing it by 3.41. 

If you want to know how much energy your space heater will use, you can use this simple calculator. 

Features to Look For in Space Heater

There are several types of a space heater in the market. Not all come with all the required features. Here are some guidelines when choosing the right space heater.


There are two main types of design for space heaters: Wall-mounted heaters, and free-standing heaters.

Wall-Mounted Space Heaters

The wall-mounted space heaters are popular among people who want to heat a small room but don’t want to occupy space with a space heater. People living in the apartments and condos with small room find this design type to be particularly useful.

The wall-mounted space heater provides excellent heating for a small to medium sized room. But, in some cases, the wall-mounting may not be practical, and it also reduces the mobility of the space heater. 

Free-Standing Space Heater

The free-standing space heater is very portable, and you can move it wherever you need.

For example, you can move it to the bedroom, office, or in the living room. The only drawback is that it uses space in the place, but you can choose a smaller size of a space heater to offset it.

The free-standing space heater is useful in a small space. But it is not very useful to heat a large room. 

Heat Distribution

Before you buy a space heater, you should know where do you plan to use it. Depending on whether you want to heat one small room or a big one, you can choose the right power rating and style of the space heater.

Temperature Control

Most space heaters come in the low and high-temperature setting. It may be enough for most of the people for general use.

But if you live in an area where the temperature fluctuates a lot, then look for space heater which has a wide range of adjustable temperature control.

This will give you more flexibility in selecting the optimal room temperature and will save you on the utility bills. 

propane space heater

Safety features

Safety is essential when using the space heater; otherwise, it increases the risk of fire and injury. We recommend that you buy space heaters, which includes the safety feature.

It means, look for the space heaters designed with proper safety features, including the build quality. The material used in it should be of good quality, and there should be no loose or hanging parts around the heater.

The unit should self-shutoff when it begins to overheat to reduce the risk of damage and fire. As an extra safety feature, we recommend a heater which has an accidental tip-over switch which turns off the heater if it falls.

Although this is optional, many branded and high-quality space heaters come with safety stamps. These safety stamps are issued by the independent testing laboratories such as ETL (Intertek) or UL (Underwriters Laboratories).

These safety seals provide extra assurance that heaters have passed the necessary safety tests. 


It is not very obvious, but noise is an important consideration when you look for the space heater. This is more so when you plan to use it indoors, such as in the office, bedroom, or living room where noise can be bothersome.

It may not be of significant issues if you are planning to use it in a garage or outdoor. Many fan-based space heaters produce more noise than non-fan-based units. Look for the noise rating on the product specification and anything below 39 decibels is quiet enough. 

Quick Heating

Who wants to wait for the heater to warm up when you are freezing in the cold?

So, look for space heater which heats up fast, especially when you are using it in an office or living room.

Most of the electric based space heater heats quicker than the oil filled radiators. These electric based space heaters use ceramic or infrared heating, which starts heating the room as soon as you turn it on. 

Programmable Control (Optional)

If you want hand-off approach to your space heater, then you may want to consider the programmable control option. It helps you pre-program the heater based on the desired schedule.

This provides you with a higher option to decide when and how long to heat the room. The heater automatically turns on and shut off based on the programmed schedule. This is helpful when you are outside, such as work, and you want the space heater to start heating the room before you come home.

But keep in mind that the more advanced and sophisticated control option you choose the cost of heating increases. 


The timer in space heater turns off the heater itself if you forget to turn it off manually. The timer on the heater allows you to set the time for the heater to turn off if you don't do it manually.

This is important as it saves the energy on not heating the room when no one is in the place for an extended period. It also reduces the chance of fire hazard.

Some space heater has auto-turn on the timer, which means it will start heating the room sometime before you arrive. This is a similar feature to programmable control type but more basic. 

Fan-Only Option

The fan-only option allows you to use your space heater during summer or hot weather. This is helpful as you can use the same space heater to use in both cold and hot seasons.


Portability is vital if you plan to move around your space heater. It helps you avoid buying a space heater for a different room as you can move your existing space heater.

A lightweight space heater which has wheels will be helpful if you want to use a space heater in different rooms. 

Heater Size

The size of the heater matters depending on where you want to use it. If you plan to place heater under the desk in your office or in a close confined space, then pick a heater with a small and slim size.

Warm Small Room

This will also help you with storing and moving the heater when not in use.

How to Use a Space Heater

Knowing the proper way to use the space heater is as important as knowing which one is the most energy efficient space heater for your home.

Here are a few things to be aware of. 

Shape And Size Of Room

As we explained earlier, the shape and size of the room matter a lot to warm the room. Use the earlier calculation to determine the power rating needed for your heater.

A wrong type of heater will cause a room to be either too hot or too cold. Plus, it will be energy inefficient, which means it will be costly to use.

For small and confined room: Use an electric space heater. It provides quick and targeted heat.

For large and more extensive size room: Use hydronic or oil-based heating. It takes a bit longer to heat but once heated the heat last longer. Oil-based heaters are generally the best space heater for a large room. 

Most Efficient Space Heater Power Source

The way you are going to operate space heater depends on the available power source and the place you want to heat.

For heating indoors, we recommend you to use an electric space heater. It does not need any exhaust ventilation and provides quick heat.

For outdoor heating such as a patio or even in a garage, we recommend using oil-based heat as it results in prolonged efficient space heating. 

Propane Heater

The propane-based heater can be used both indoor and outdoor. It produces less smoke than other petroleum-based heaters. Reasonable ventilation is required when using a propane-based heater.

Propane tank needs safe storage as it comes in a highly compressed gas container. Read the manufacturer operating manual for the secure handling of propane. 

Kerosene Heater

We recommend you to use kerosene heaters outdoor such as on patios, garage or camping. Kerosene is a cheaper and energy efficient way to heat any area.

But since the kerosene produces lots of smoke when it burns, you need good ventilation. This also helps avoid getting kerosene fumes and prevents the risk of generating carbon monoxide gas, which is lethal. 

Electric Heater

Electric heaters are very portable and easier to use. It is preferred for both indoor and outdoor use and wherever you can get a reliable electricity source.

Room Ceiling

The height of the room impacts a lot when using a convection type of heating, such as the use of fan and blowers. When heated, the hot air gets lights and rise up, pressing down the cold air in a room.

Higher ceiling means the heater has to warm the whole room to be effective. If you have a higher ceiling, then pick a space heater which provides very directional heating such as an infrared heater.

This will provide you the quick warmth in an energy efficient way. Also, consider the right power rating depending on the size of the room. 

Room Insulation

The proper room insulation is essential for the most energy efficient space heating. Poor room insulation means more heat loss and less efficiency.

In many houses, most of the heat is lost through the windows and roof. To prevent it, make sure you have a well-insulated roof and install double glazed windows to keep the warmth. 

Also, close any open door or windows to reduce the heat loss.

Money Saving Tips for Most Energy Efficient Space Heater

Here are some tips to reduce your heating bills.

Turn Off The Heater When Not In Use

This is a common sense approach as you don't need to heat a room when there is no one inside. If you don't want a cold place when you arrive from outside, you can use a timer or programmable control.

The timer automatically turns on the heater beforehand. Some smart home space heater also comes with a control app which you can use to turn on the heater remotely.

In this way, you will have a warm room without wasting unnecessary power. 

Extension Cord

If you are using an electric heater, then plug it straight into the wall outlet. The heater draws a significant current. The use of inferior, lower grade or damaged extension cable may result in a short circuit which may cause the fire.

If you must use an extension cable, then use proper quality heavy duty cord with a 14 gauge wire. Also, look for the highest load-bearing capacity on the extension cable. Although tempting, don't plug several devices on the same extension cable as it increases the load on the wire. 

Avoid Loose Ends

Don't place the heater near loose-hanging clothes such as near bed or furniture which may result in it catching fire.

Also, don't place it close to items which absorb the heat such as a bed. It will result in poor heat distribution, and you may have to heat longer. 

window close for space heating

Close the gap

Heat moves out whenever it finds the crack. You should close any gap in the door and windows to keep the heat inside.

Try to minimize opening the windows or door, which results in heat loss. This is more important when you use convection type heaters. 

Space Heater In Bathroom

Don't use a space heater in the bathroom or near the water source if it is not rated to handle in those places. The high amount of moisture in the bathroom may condense and increases the risk of short-circuiting the space heater.

If you have to use a space heater in the bathroom, then use specially designed bathroom space heater such as Lasko bathroom Space heater. 

Inspect Heating System

We recommend that you inspect your central heating system at least once a year. This will allow it to work more efficiently, and you don't have to use the space heater much.

Next, we have picked 9 space heaters for each category which is the best on its own. 

You can choose any space heater as per your need, and we are confident that you will not be disappointed. 

Our Top Pick

 Dr Infrared Heater Portable Space Heater

Dr Infrared Heater Portable Space Heater

Infrared Dr. Heater Portable Space Heater is our top pick for the most energy efficient space heater. The use of infrared technology makes it highly useful in converting electricity into heat.

It delivers 60% more heat than similar heating units. The automatic tip-over protection and overheat shut-off are a nice safety feature. It makes this unit to be safe to use indoors and outdoors.

Infrared heat does not dry off the air, which is essential to people who are sensitive to dryness. Best of all, it is tranquil and portable, which makes it ideal to use while at work or rest.


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About the author

Hi, I'm Sunny Kay, an avid gardener, home decorator and outdoor enthusiast. I help busy people get into gardening, create natural and good looking home decorations, and suggest outdoor activities and tools to explore the nature. Click Here to get started with my recommended gears.

Sunny Kay

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