All About Space Heater Efficiency & Types of Space Heaters

Sometimes, whole-house or office heat just isn’t enough to beat the cold. If you’ve found yourself shivering at home or in the office, you’ve probably considered getting a space heater. In addition to concerns about space heater efficiency, many people worry about safety, especially in areas with high traffic or children.

Fear not – space heaters, when used properly, offer great advantages, both in heating and saving money. By using your space heater efficiently and remembering a few tips, you’ll be able to save money and stay warm.

In this blog post we explore the pros and cons of space heaters, the different types of space heaters, and the situations for which a space heater is appropriate.

What are Space Heaters?

As the name suggests, a space heater is a heating device used to provide heat for a given space, usually a single room or a medium-sized open area. 

Space heaters come in different types of heating designs:

Fan heater – Also known as blow heaters, they are the least expensive but also the least efficient. They work by using a fan to pass the air over a heat source, dispersing the heated air to the rest of the room. In essence, they are electric fans with a heating element.

Ceramic heater – These use a heated ceramic material as the heat source. The difference over fan heaters is safety: the ceramic material has a higher resistance to Curie temperatures, making it safer than the resistance wire used by fan heaters.

Infrared heater – These models use infrared radiation to provide heat. This enables them to be more efficient than fan or ceramic heaters, while making them smaller and quieter (due to not needing a fan to disperse the heat). 

Oil heater – Also known as oil-filled heater, oil-filled radiator, or column heater, this uses electricity to heat oil, which then transmits heat to the metal wall through convection. Like the infrared heater, oil heaters do not require fans, making them quieter. However, they take longer to heat up. 

Space heater capacities range between 10,000 to 40,000 BTUs. 

How Space Heaters Work

There are three heating methods that space heaters use to warm up a room:

Convection – This involves heating the air itself and distributing it around the room. This is how fan and ceramic heaters work.

Conduction – This involves heating nearby objects to transfer heat throughout the room. The oil heater transfers heat this way, by warming up the oil, which then heats the unit, which then warms nearby objects. For example, a blue flame space heater works by heating the air in a room. When the heater turns on, it will start by heating the wall where it is installed, eventually making its way up to heat the room from the floor to the ceiling. 

Radiation – This is when the heat is directly transferred to objects and people around the room. This is usually the fastest form or heating to be felt, and is used by infrared heaters.

Do Space Heaters Work?

Yes! Space heaters work well as a supplemental heat source for homes and offices. This does not mean that you should rely on space heaters as a primary heat source; however, if you have a particularly drafty room in your home or part of your office building, a space heater will work hard to keep that area warm.

The heat productivity and cost efficiency of your space heater depends entirely on how you use it. If you’re only wanting to supplement heat in one room or small area, the benefits of a space heater are well worth it. However, if your whole house or business heat just isn’t cutting it and you’ve got one in every room, well…that’s when the space heater efficiency drops significantly.

When They Do Work

  • Supplemental Heat: Space heaters are designed to be a supplemental heat source. For this purpose, any type of space heater – whether gas, electric, or kerosene – will work well. If you need supplemental heat for employees in your place of business, infrared heaters or smaller, more compact electric heaters make a great option.
  • Single-Room Heating: Space heaters also work great for heating only the space you’re currently occupying. This works well if you’re wanting to leave the thermostat turned down to limit whole-house heat costs, or someone else likes the house a little colder than you do. This isn’t much more expensive if you limit space heater use to when you’re physically present in the room. Wearing layers can also help keep your heating output needs lower.

Choosing the right-sized space heater will greatly help you cost-to-heat ratio. If you’re only needing to heat a small area when you’re occupying it, a small infrared or portable electric heater will be your best bet. If you’re needing supplemental heat in an entire room, a gas or medium-sized electric heater makes the most sense. Kerosene heaters work well for large, well-ventilated areas, such as a garage or shop area.

When They Don’t Work

  • Whole House Heat + Space Heater = Not Enough: If you notice that you’re using a space heater and still running your whole-house heat full-blast, perhaps consider a different method. If it’s too chilly to turn down your thermostat and only supplement with the space heater, a mini-split heat pump system or other alternative like a wall unit might be something to consider.
  • Complete Heat Source: Space heaters are not designed to be your only source of heat. Continuously running one as the sole heat source puts a lot of strain on your wallet. Whether you’re using an electric model that creates higher power costs, or a kerosene or gas model that can be dangerous in unventilated areas, space heaters are impractical as a complete heat source.

Types of Space Heaters

There are two types of space heaters that we carry at Total Home Supply: vent-free blue flame heaters, and vent-free infrared heaters (also known as radiant heaters).

Vent-free blue flame heaters

Vent-free blue flame heaters use natural gas or liquid propane as a fuel source and work by heating the air in the room. Because these types of heaters heat the air in a room (as opposed to the objects in the room), blue flame heaters are best used in insulated spaces. As a bonus, the heater’s flames offer a nice ambiance to make you feel extra cozy.

Our pick:

Empire Comfort Systems Blue Flame Vent Free Gas Heater

The BF-30 is equipped with a hydraulic thermostat and modulates from 8,500 BTUs to 30,000 BTUs for continuous temperature control. With a modulating hydraulic thermostat once the preset comfort level is reached, the unit cycles the main burner flame from HI to LO and, when the thermostat is satisfied, to OFF while still leaving the pilot on. This reduces the large flame to a smaller flame while still emitting heat. Available in Natural Gas BF-30WN and Liquid Propane BF30WL.

Empire Comfort Systems BF-30W 30,000 BTU Blue Flame Vent-Free Gas Heater with Thermostat
Price: $769.00 Empire Comfort Systems BF-30W 30,000 BTU Blue Flame Vent-Free Gas Heater with Thermostat

The BF30W produces an inviting warmth quickly and efficiently. A Blue Flame heater will warm the room starting with objects in the room including the wall on ...

View Product


Vent-free infrared/radiant heaters

Infrared heaters, also known as radiant heaters, also use either natural gas or liquid propane as a fuel source. The difference between these heaters and blue flame heaters is the type of heat they produce. Infrared heaters produce radiant heat, which is also the type of heat generated by the sun or a burning fire. This type of heat directly heats the objects in the room rather than the air itself, meaning you’ll warm up almost immediately.

Our pick:

Heatstar HSSVFRD20 20000 BTU Vent Free Infrared/Radiant Heater with Thermostat and Blower

Vent Free Radiant heaters are extremely economical, operating at 99.9% efficiency and the HeatStar heaters feature a built-in low oxygen shut-off sensor for safety. The HSSVFRD20 20,000 BTU Radiant heater features a blower fan and thermostatic control. This size heater is great as a supplemental heat source for spaces up to 500 square feet.

This heater includes the AA batteries required for the Electronic “push-button” ignition. The thermostatic control knob offers 5 settings. The burner will cycle on and off based on the set temperature. Because it is gas powered, it will keep you warm, without electricity, during power outages. The blower fan will not operate during a power outage, but the heater will still generate heat to keep you warm and comfortable.

The 20,000 BTU radiant heater is available in Natural Gas (HSSVFRD20NGBT). Note that vent-free products cannot be shipped to California.

Heatstar HSSVFRD20 20000 BTU Vent Free Infrared/Radiant Heater with Thermostat and Blower, Choice of Fuel Type
Price: $387.00 Heatstar HSSVFRD20 20000 BTU Vent Free Infrared/Radiant Heater with Thermostat and Blower, Choice of Fuel Type

HeatStar by Enerco offers gas powered, vent free heating options for your warmth and comfort. The HSSVFRD20 20,000 BTU Radiant heater features a blower fan...

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Of course, there are other types of space heaters on the market. These include:

  • Electric space heaters: Electric space heaters come in a wide variety of styles, from ceramic tower style space heaters, which oscillate to distribute warm air throughout the room, to fan-style space heaters, which utilize a fan to blow out warm air. There are also electric space heaters that utilize infrared heat to deliver immediate warmth.
  • Kerosene space heaters: Kerosene space heaters offer very powerful heating without relying on electricity, making them ideal for use in power outages. There are a couple of downsides to these types of heaters, though. Kerosene is more expensive than other types of fuel, which may inhibit some folks from purchasing these types of heaters. Furthermore, kerosene space heaters should only be used in ventilated areas due to the amount of gasses they produce.
  • Infrared heating panels: These types of electric space heaters lay flat against a wall and deliver quality, radiant heat. Thanks to their contemporary look, infrared heating panels are aesthetically appealing for many homeowners — in fact, some heating panels feature artistic prints or mirror-like finishes, blending decor and function!

The type of space you need to heat will factor largely into which model you’ll end up choosing. If it’s in a busy area or you have kiddos running around, you’ll probably want a model that’s cool to the touch and has automatic shut-off.

If you’re looking for a space heater for your office, a compact heater that fits under your desk is likely your best bet. Slightly larger spaces or rooms require a larger heater to make a difference without tacking too much extra onto your heating bill.


Space Heater FAQs


Can You Sleep with a Space Heater On?

Technically yes, you can sleep with a space heater on, provided that it is equipped with automatic shut-off and tip-over detection technology. However, due to the risk of fire, it is still not wise to leave space heaters running unattended, including while you sleep.


Things to Keep in Mind:

  • Ventilation: Whether you’re burning natural gas or propane, unvented gas space heaters off-gas, much like the kerosene heaters, so the space you’re heating needs to remain well-ventilated. Unvented space heaters are not recommended for overnight or long-term use.
  • Unvented vs. Vented: Unvented gas heaters don’t vent exhaust outside, so they’re rated as more efficient when it comes to heat vs. cost. They’re also prone to add moisture to the air, so keep this in mind if you’re sensitive to high-moisture content or live in an already humid climate. Ventless heaters are rated for up to 30,000 BTUs, which means their use should be limited to smaller rooms and spaces for a few hours at a time. Vented heaters are slightly less heat efficient as they exhaust, but are better for less-ventilated living areas.


What Should I Look For in a Space Heater?

✔ Heating type

Consider the space and your budget. Do you have a small space and budget? A fan heater may be adequate for heating the space, or acting as a supplemental heat source in the dead of winter. Is it a larger space? An oil filled heater may be more apt, it can take a while to heat up but capable of warming bigger rooms. Do you have a bigger budget to spend? An infrared heater provides the quickest heating that can be felt immediately.

✔ Power source

Space heaters can be powered by electricity, propane, natural gas, and kerosene. Electric heaters typically have the lowest BTU. Gas-powered heaters have higher heating capacity for larger spaces, but need appropriate safeguards such as ventilation for safety.

✔ UL label

New space heaters models have current safety features. Check if the heater has the Underwriter’s Laboratory (UL) label.


Do Space Heaters Use A Lot of Electricity?

Unfortunately, space heaters use a lot of electricity to run. The cost of electricity varies by state, and if you’re overly relying on your space heater to get you through the winter months, you can expect to pay for it. To stay warm without paying an arm and a leg for electricity, it’s best to use an electric space heater only when you need it. Note: Total Home Supply only carries gas space heaters and does not sell electric space heaters.

Is It Cheaper to Run the Heat or a Space Heater?

Overall, it is cheaper to run the main heating system in a home than to use a space heater. A space heater is meant to be used as a secondary, supplemental heat source, not as the sole source of heat. That being said, you may be able to save some money by pairing a space heater with your primary heating system. If you turn down the thermostat in your home and supplement with a space heater, it’s possible to see your heating bill decrease.



Space heaters can be a very effective and cost-efficient way to stay a little bit warmer in your home or business. Space heaters are generally designed with the intent to heat only the area you’re currently inhabiting, and are great for room-to-room use in places with multiple inhabitants, as room temperature preferences vary from person to person.

By keeping in mind the size of the area or room you need heated, the type of heat you’re looking for, and the fact that space heaters are designed to only be a supplemental source of heat, you can prevent high energy bills and keep your family or employees happy and toasty. Browse our heaters and you’ll be well on your way to a warmer winter.



Mickey Luongo

Mickey is the resident heating and air conditioning expert with over 15 years of experience in the industry.


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