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The Different Types of Space Heaters and How They Work

how do space heaters work

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. 

Space heaters can be a convenient option for small spaces or rooms that require supplemental heating. These compact heaters are available in both gas and electric. In this blog post we explore what space heaters are, the different types and models, and 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 are distinct from other types of heaters in that:

  • They are usually self-contained and require no ducts 
  • They are designed to service a small space or single room

Space heater capacities typically range between 4,000 to 40,000 BTUs. 

What are the Different Types of Space Heaters?

Space heaters come in different types of heating designs. While many may only think of small electric plugin heaters when they think of space heaters, we will focus on the safer and more permanent solutions to a cold space.

Portable 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.

Ventless Gas Heater – Available in blue flame and infrared, these heaters connect to a natural gas or propane line and can provide heat in a variety of spaces. Much more powerful than portable electric heaters, these are great choices for spaces that always need supplemental heat. They are available with or without blowers.

Wall Mounted Electric Heaters – While a portable fan heater can be a good choice for occasional heating needs, a wall mounted electric heater serves as a real solution that can be used all the time without fear of safety issues like tipping. Several kinds are available including cove heaters for installation higher on the wall, baseboard heaters for installation near the floor, and wall heaters for installation on the main part of the wall. Heaters like this can be used for supplemental or primary heat.

How Do 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.

Are Space Heaters a Viable Heating Option?

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.

Where Can I Use Space Heaters?

As 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.

For 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. 

Where Should I NOT Use Space Heaters?

X As a sole 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.

X When it’s 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 may be a better option.

How to Choose a Space Heater

1. 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.

2. 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? A ventless gas heater can serve as an efficient way of warming it up quickly. . Do you have a bigger budget to spend? A more permanent electric solution like a baseboard heater may be the best choice with a hardwired power source and a thermostat..

3. Choose the right size

Most heater manufacturers provide a general sizing table that indicates the size of the room a particular heater can accommodate. Buying an oversized heater can result in energy waste and unnecessary utility costs, while getting an undersized heater could result in inadequate heating and cold indoor temperatures. For the most accurate calculation, have a local HVAC contractor perform a manual J heat loss calculation.

. UL label

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

5. Look for thermostatic control

A thermostatically controlled heater monitors the temperature of the room and scales back the unit’s operation once the desired temp level is reached. This avoids energy wastage and makes the heater more cost-efficient.

6. Look for tip over safety

A space heater with a tip-over safety feature automatically shuts off the unit in case it gets knocked down or tipped over, minimizing the risk of fire.

Our Recommended Space Heaters for 2023

We carry several types of space heaters at Total Home Supply: ventless blue flame heaters, ventless infrared heaters (also known as radiant heaters), electric cove heaters, electric baseboard heaters, and electric wall heaters.

Ventless 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 picks:

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: $809.00 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 ...

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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 picks:

Empire Comfort Systems SR-18TW Vent-Free 18000 BTU Infrared/Radiant Gas Heater/Thermostat Control

This ventless infrared heater comes in natural gas and liquid propane versions and operates at 99.9% AFUE efficiency. It delivers 18,000 BTUs of heating and can service medium-sized rooms. 

A push-button ignitor lights the pilot, eliminating the need for matches. The thermostatic controls are located on top for easy access. An Oxygen-Depletion Sensor shuts off the unit if there is not enough available fresh air for safety.

The heater comes with wall and floor stand kits for flexible mounting options. Note that it cannot be shipped to California.

Empire Comfort Systems SR-18TW Vent-Free 18000 BTU Infrared/Radiant Gas Heater/Thermostat Control
Price: $779.00 Empire Comfort Systems SR-18TW Vent-Free 18000 BTU Infrared/Radiant Gas Heater/Thermostat Control

The SR18TW is a white, infrared gas heater. It is compact in size and will install on a wall. It features top mounted, thermostatic controls and will add radian...

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Cove Heaters

Cove Heaters use a combination of radiant heat and convection to give you a long lasting warmth throughout your room. 

When the heater is turned on, it emits radiant heat. This immediately warms the room like the sun by heating the objects in the room as well as the air. The second part of heating is through convection. Cold air is drawn in from the bottom of the heater through natural convection, and warm air is then discharged from the top of the unit, helping to maintain the warmth.

Recommended Cove Heater:

King KCV2406-W 47″ 420/560 Watt Electric Cove Heater – 208/240 Volt

King’s KCV-Series Cove heaters are a great solution for safe heating in almost any installation. They are installed at least 6 feet from the floor/closer to the ceiling*, making them safe for installation in schools and day care centers.

This particular model is 47″ long and emits 420/560 watts of electric heat, enough for medium-sized rooms. As a cove heater, it has no moving parts so it operates silently and doesn’t blow dust or particles around the room.

This heater is a great option for rooms with limited wall space, since it can be mounted high on the wall just below the ceiling. And since heat is emitted from above, temperature fluctuations are minimized, providing better comfort while saving space.

King KCV2406-W 47" 420/560 Watt Electric Cove Heater - 208/240 Volt
Price: $295.00 King KCV2406-W 47" 420/560 Watt Electric Cove Heater - 208/240 Volt

The King KCV-Series Cove heaters are a great solution for safe heating in almost any installation. They are installed at least 6 feet from the floor/closer ...

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Baseboard Heaters

As the name suggests, baseboard heaters are installed along the baseboard at the bottom of the wall. They are designed for this location since by starting out along the floor, the heat emitted rises into the area between the floor and ceiling, allowing for better heating across the room.

Baseboard heaters are usually installed underneath windows or on perimeter walls. This allows them to counteract the cold that seeps from window glass or exterior walls where heat loss tends to occur. They come in electric, gas or hydronic versions, also known as hot water baseboard heaters. 

Recommended baseboard heater: 

Ouellet Sublime Electric Baseboard Heater – 240/208 Volt

This sublime baseboard heater features a draft-barrier type upflow air outlet.The advantage of this type of air outlet is that a film or shield is created between the cold glass and the indoor air, making it perfect for windows. They can even be installed in restrooms!

It boasts a slim design, just under 3″ deep and rising about 7″ high. It has a sleek, polished design that will discreetly into any space, and comes in white or metallic charcoal.

Ouellet Sublime Electric Baseboard Heater - 240/208 Volt
Price: $225.00 Ouellet Sublime Electric Baseboard Heater - 240/208 Volt

The Sublime Baseboard heater is not your mother's baseboard heater! This 240/208V electric heater features a new, polished design that will blend discretely int...

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Wall Heaters

Wall heaters save valuable space by mounting directly on to a wall. They are ideal for single rooms or tight living spaces. Unlike portable space heaters, they don’t use outlets and are instead wired directly to a circuit in the electrical panel. This avoids unsightly wires snaking along the floor to trip on.

Recommended wall heater:

King KCF2-2020-1-S-T 2000 Watt, 2 Ft. Wide Surface Mounted Cabinet Wall Heater

This slim wall heater juts just 4” from the wall. This makes it the perfect heating option for narrow hallways or entryways. But don’t let its compact size fool you – it can put out 2,000 watts of heat, or 6,800 BTUs.

Designed and built to withstand heavy duty commercial and institutional usage, it uses impact-resistant 18-gauge ceramic core heating elements, permanently lubricated bearings, and aluminum plate fins for rapid heat transfer. It also features a single whisper-quiet squirrel cage blower.

At 208 volts, the KCF heaters are for commercial use. If residential use is desired, a Manual Reset Limit Option must be installed.

King KCF2-2020-1-S-T 2000 Watt, 2 Ft. Wide Surface Mounted Cabinet Wall Heater - 208V
Price: $2,559.00 King KCF2-2020-1-S-T 2000 Watt, 2 Ft. Wide Surface Mounted Cabinet Wall Heater - 208V

The King KCF2-2020-1-S-T compact heater is a slim 4" surface wall mount electric cabinet heater with 208 volt electricity. Built-in features of this...

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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.

Conclusion

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.

2 thoughts on “The Different Types of Space Heaters and How They Work”

  1. Tiny House Heat & AC - Best Ways to Heat and Cool a Small Home says:

    […] find that there are spots that are just a bit colder than others. In these instances, getting a small space heater could work for heating those specific […]

  2. Heating and Cooling Options for an Addition to Your Home says:

    […] turn on as needed. For spaces like this, you might want to get a gas or electric fireplace, or space heater. That way, you are only paying for the heat when you actually require […]

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