How do Electric Heaters Work?

Demystifying Electric Heaters: How They Work and Where to Use Them


When the chill of winter creeps in, the thought of a warm, cosy room is comforting. But have you ever wondered how that electric heater in your room works? Or perhaps you’re considering buying an electric heater, but are unsure about the different types of electric heaters and their uses? This article aims to provide you with a comprehensive understanding of how electric heaters work, the different types available, and which scenarios they are best suited for.

The Basics of How Electric Heaters Work

Electric heaters work based on the principle of conversion of electrical energy into heat energy. Here is a basic breakdown of how they work:

  1. Electricity Input: When you plug in an electric heater and turn it on, electricity flows into the heater. This electricity is what will be converted into heat.

  2. Resistance Heating: The electricity flows through a resistive element in the heater (often made of a conductive material like nichrome). As the current passes through this resistive element, the resistance causes the element to heat up.

  3. Heat Dissipation: The heat generated by the resistive element is then transferred to the surrounding area. Different types of electric heaters do this in different ways. For example, in a convection heater, the heat warms the air directly above the heater, causing it to rise and circulate around the room. In a radiant heater, the heat is emitted in the form of infrared radiation, which warms objects and people directly without heating the air.

  4. Thermostat Control: Most electric heaters have a built-in thermostat that monitors the temperature of the room. When the room reaches the desired temperature, the thermostat will signal the heater to turn off or reduce its heat output. This helps to maintain a consistent temperature and also makes the heater more energy-efficient.

The Four Main Types of Electric Heaters

Electric heaters come in various shapes and sizes, each serving a unique purpose. Despite the differences in their design and functionality, all electric heaters essentially draw on electricity to provide heat.

However, the way they deliver this heat varies significantly. The four main types of electric heaters are convector heaters, oil-filled radiators, halogen heaters, and fan heaters.

Convector Heaters

What is a convector heater? Convector heaters, also known as convection heaters, provide an efficient way to heat a room by manipulating the natural flow of air. They contain a heating element that warms the air directly above it. As this warm air rises, it creates a vacuum that pulls in cooler air from below. This cold air then gets heated, creating a continuous cycle of warm air rising and cold air being drawn in. This process results in a consistent and even distribution of heat throughout the room.

These heaters are typically lightweight and portable, making them easy to move around according to your needs. They also operate silently, which makes them perfect for environments where quiet operation is essential, like bedrooms or offices. Many models come with a thermostat and timer, allowing you to control the temperature and heating schedule effectively. However, it’s worth noting that as convector heaters rely on air circulation, they may not be the best choice for drafty rooms or areas with high ceilings.

Oil Filled Radiators

What is an oil filled radiator? Oil filled radiators work by using electricity to heat up oil that’s sealed inside the radiator. The heated oil then circulates around the coils or fins of the radiator, emitting heat into the room. Due to the high specific heat capacity of oil, these radiators can retain heat for a long time, even after the heater is switched off. This means they continue to emit warmth into the room, providing consistent, long-lasting heat.

These heaters are excellent for maintaining a steady temperature over extended periods, making them ideal for colder climates or during winter months. They are also very quiet since they don’t use a fan, making them suitable for use in bedrooms or study areas. However, they take longer to heat up compared to other types of heaters, so they might not be the best option if you need immediate warmth.

Halogen Heaters

What is a halogen heater? Halogen heaters utilize a halogen bulb as their heating element. When electricity passes through the bulb, it gets heated and emits infrared radiation. This radiation directly heats any objects or people in its path, providing instant warmth. Unlike convection heaters that heat the air, halogen heaters warm up the objects and people directly, making them a good choice for smaller spaces or for personal use.

These heaters provide instant heat, making them ideal for quickly warming up a space. However, they are not as effective at heating larger rooms or maintaining a consistent temperature over time. Also, the bulbs can get very hot, so it’s important to keep safety considerations in mind when using these heaters.

Fan Heaters

What is a fan heater? Fan heaters work by using a fan to blow air across a heated element. This process disperses the heated air throughout the room quickly, providing immediate warmth. The rapid heating capability makes fan heaters an excellent choice for spaces that are poorly insulated or for situations where quick heating is required.

These heaters are typically compact and portable, making them easy to move around as needed. They also often come with adjustable timers and multiple heat settings, providing greater control over the heating process. However, fan heaters can be noisier compared to other types of heaters due to the fan mechanism, and they can cause a room to feel dry over time.

How Much Electric Does Each Heater Use?

The amount of electricity that a heater uses depends on its power rating, which is typically measured in watts (W), and the length of time it’s running. The higher the power rating and the longer the heater is on, the more electricity it will consume. Your UK electricity company will charge you per kWh (kilowatt-hours), as it stands, the average kWh in the UK is 0.28p, if you ran a 1000W (1 kWh) electric heater for 1 hour, it would cost 0.28p. The cost to run a common 2000W electric heater per hour would be 0.56p.

  1. Convector Heaters: Convector heaters typically have a power rating between 500 to 3,000 watts. Therefore, if a 2,000-watt convector heater is run for one hour, it will consume 2 kilowatt-hours (kWh) of electricity.
  2. Oil-Filled Radiators: Oil-filled radiators generally use between 1,000 to 2,500 watts. So, a 1,500-watt oil-filled radiator will consume 1.5 kWh of electricity if it runs for one hour.
  3. Halogen Heaters: Halogen heaters usually have a lower power rating, ranging from 400 to 1,200 watts. This means a 800-watt halogen heater will use 0.8 kWh of electricity in one hour of operation.
  4. Fan Heaters: Fan heaters often have a power rating between 1,000 to 2,500 watts. For example, a 2,000-watt fan heater will consume 2 kWh if it’s run continuously for one hour.

Please note that these are only estimates as the actual power consumption can be influenced by various factors such as the thermostat setting, the room’s insulation, and the outside temperature. Also, many heaters don’t run continuously but cycle on and off to maintain the set temperature, which can reduce their energy usage. To calculate the cost of running a heater, you would need to multiply the amount of kWh the heater uses by your local electricity rate.

Can You Get Electric Heaters That Can Run For Pennies an Hour in the UK?

While it’s a nice thought to think that you could heat a room for just pennies an hour, the reality is that electric heaters often cost more than that to operate. The cost of running an electric heater depends on two main factors: the power rating of the heater (measured in kilowatts, kW) and the cost per kilowatt-hour (kWh) charged by your electricity provider.

For instance, let’s consider a relatively efficient space heater that operates at 1.5kW. If your electricity cost is around 28 pence per kWh, running this heater for one hour would cost: 42 pence.

Also, it’s worth noting that while electric heaters can be more expensive to operate compared to some other types of heaters (like gas heaters), they are often cheaper to install and maintain, and can still be a cost-effective choice for heating small spaces or for supplemental heating. Ultimately, the cost-effectiveness of an electric heater will depend on your specific heating needs, the insulation of your home, and your local electricity rates.

In Conclusion

Electric heaters work by converting electrical energy into heat energy. This process occurs when an electric current passes through the resistive elements within the heater, causing them to heat up. The heat is then released into the surrounding environment, warming up the space.

There are various types of electric heaters, including convector heaters, oil-filled radiators, halogen heaters, and fan heaters, each with their own unique mechanisms for generating and distributing heat. Convector heaters, for instance, heat the air directly above them, creating a cycle of warm air rising and cold air being pulled in. On the other hand, oil-filled radiators circulate heated oil around the coils of the radiator, while halogen heaters radiate heat from a halogen bulb, and fan heaters blow air over a heated element to distribute warmth quickly.

While electric heaters can be more expensive to operate compared to some other types of heaters, they are often cheaper to install and maintain, making them a cost-effective choice for heating small spaces or for supplemental heating. However, the actual cost-effectiveness will depend on your specific heating needs, the insulation of your home, and your local electricity rates.

Understanding how these heaters work can help you make an informed decision about the best heating solution for your home or office. Remember to consider factors like the size of the space, the level of insulation, and your heating needs when choosing an electric heater.

Each type of electric heater has its unique method of operation and is suited to different scenarios. Understanding these differences can help you determine which electric heater will best meet your needs, ensuring you stay warm and comfortable throughout the colder months.