What does 100% efficient actually mean?

When an electric heater is described as 100% efficient at the point of use, it means that the electrical energy consumed by the heating element is converted into heat within the property.

There is no heat being lost through a flue or pipes as there is with other heating systems. Put simply, if an electric heating element consumes 1kWh of electricity, approximately 1kWh of heat is produced at the point of use.

But this does not mean that every electric heating system will have the same running cost or provide the same heating experience.

That distinction is important. Efficiency isn’t the same as running cost

Electric heating can be 100% efficient at the point of use, but that doesn’t automatically make it the cheapest form of heating to operate.

The cost of heating a property depends on several factors, including the price of electricity, the amount of heat the property requires, how the heating is controlled and how the system is used.

This is why simply comparing the efficiency percentage of different electric radiators doesn’t tell the whole story. Conventional electric heaters are all fundamentally converting electricity into heat.

The differences come in how that heat is controlled, delivered, distributed and, in some technologies, retained.

The importance of accurate temperature control

Good temperature control is an important part of an effective electric heating system. An electronic thermostat monitors the room temperature and controls the heating element to maintain the temperature selected by the user. Once the required temperature has been reached, the element does not need to operate continuously.

Programming can further improve control by allowing heating to operate around the daily routine rather than simply being switched on for long periods.

Modern smart heating systems can take this further, allowing users to control individual radiators remotely, adjust temperatures through an app and make changes when their routine changes.

Features such as open-window detection and holiday settings can also help reduce unnecessary heating.

How does an electric radiator transfer heat?

The way heat is delivered into a room is another important consideration. Electric radiators can transfer heat through a combination of radiation and convection.

Radiant heat is transferred from the heated surface to people and objects within the room. Convection warms the surrounding air, which then circulates naturally through the space. The balance between these methods depends on the radiator’s construction and design, its operating temperature and the conditions within the room.

Neither method should simply be labelled “more efficient”. They are different ways of transferring heat and good radiator design is about delivering that heat effectively and comfortably into the occupied space.

Does a higher wattage mean a better radiator?

Not necessarily.

A radiator’s output should be appropriate for the room in which it is installed. The amount of heat required can be influenced by the room’s dimensions, insulation, glazing, external walls, ceiling height and the construction of the property. Correct sizing is therefore an important part of designing an effective heating system.

A radiator that is appropriately sized for the space should be capable of maintaining the desired temperature without being unnecessarily large for the application.

For larger or more complex properties, a proper heat-loss assessment can provide a much more accurate basis for selecting radiator output than room size alone.

What about heat retention?

Not all electric heating technologies are designed to deliver heat in exactly the same way.

Some electric radiators are designed to respond quickly to changes in room temperature, while other technologies store heat and release it over a longer period. High Heat Retention (HHR) storage heaters, for example, are specifically designed to store heat within a high-density core and release it gradually. This can be particularly useful where longer periods of background warmth are required and can allow greater use of available off-peak electricity.

The most appropriate technology depends on the building, occupancy pattern, heating requirements and how the property is operated.

Looking beyond the “100% efficient” headline

The phrase 100% efficient at the point of use is useful, but it is only one part of understanding electric heating. When assessing a heating system, consideration should also be given to thermostat accuracy, programming, heat distribution and characteristics, controllability and the individual heat requirements of the property.

Electric heating is constantly evolving

Electric heating has moved a long way beyond the simple panel heater.

Today’s products can incorporate sophisticated electronic thermostats, WiFi connectivity, app control, voice integration, open-window detection, programmable schedules and different approaches to heat retention and heat distribution. This gives considerably more control over when, where and how heating systems operate.

At Electrorad, we have been specialising in electric heating for more than two decades, working across residential, commercial, education, hospitality and specialist accommodation projects.

That experience has shown us that there is no single heating technology that is right for every property.

The best solution starts with understanding the building, the occupants and how the space will actually be used.

The bottom line

Electric resistance heating can be 100% efficient at the point of use, but effective electric heating is about much more than that figure.

The combination of appropriate sizing, good radiator design, accurate controls, intelligent programming and the right heating technology can make a significant difference to comfort, controllability and the way energy is used.

At Electrorad, we believe good electric heating starts with understanding the technology — and choosing the right solution for the application.

Electric heating, properly understood.