Electric heater and radiator buying guide

If you're looking to purchase several heaters, take the time to carefully weigh up your options, compare models and install a programming system (pilot wire, energy management system, etc.). Finding the right heater or radiator will come down to a combination of different factors.

1. Room type: a bathroom won't be heated the same way as a bedroom, for example.

2. Thermal comfort: important for general well-being, this will depend on the type of heat ouput provided by your system.

3. The time a device takes to heat up will depend on the room in which it is used as well as the habits of the user.

4. The volume of the room you want to heat and how well your home is insulated: large, poorly insulated homes require a lot of energy to heat.

5. Budget: you may find there is a discrepancy between the perfect model and your bank balance!

Choosing the right radiator for the room

Modern storage radiators work best for living spaces as they are cost-effective and distribute heat evenly. If you do not have a timer for your bathroom heater, pick a model with a fan system. For example, a heated towel rail fitted with a fan heater will provide faster heat-up times. Hallways and kitchens can usually get by with a convector or radiant heater as they are not in constant use. Nonetheless, a storage heater will almost always be the most efficient option, regardless of room type.

Calculating heater power

To calculate how much power you need from your heater, multiply the surface area in m² by 100 W for poorly or moderately insulated homes, or by 60 W for homes that are very well insulated. For bathrooms, multiply the surface area by 125 W.

Thermal comfort

Thermal comfort is linked to the way in which the heater or radiator distributes heat. The greatest level of comfort is provided by modern storage radiators, both in terms of heat and energy consumption. Convector heaters are inexpensive to purchase but use a lot of energy and do not necessarily emit the most pleasant form of heat. A fan heater should be able to heat a bathroom or small room in around three minutes flat. But pay attention to your energy bill because these devices can really rack up on the meter! With this in mind, fan heaters should only be used occasionally. Similarly, a radiant heater can be installed in a room that is only used from time to time. These devices produce a similar kind of heat to sunlight – the closer you are to them, the warmer you'll be.

As a point of reference, a constant temperature of around 19°C is recommended for living rooms, while 16°C is best for bedrooms. Bathrooms should ideally be kept at around 17°C while not in use and 22°C when they are.

Electric heating systems are split into three categories according to the type of heat transfer used: convector heaters, radiant heaters and storage radiators.

Electric convector heaters

Convector heaters heat the air directly using an electric element. The heated air rises and is replaced by incoming cool air which is then heated in turn. The heat is distributed through the room by the natural movement of the air as it's heated in a process known as convection. One unwanted result of convection is that the air dries out somewhat. What's more, these heaters tends to heat up spaces unevenly and the air generated can move around dust.

With these factors in mind, convector heaters are best suited to well-insulated hallways as these spaces heat up quickly. Opting for a model with a fan will ensure extra fast heat-up times. As convector heaters tend to dry out the air, it is sometimes recommended to use them alongside a humidifier to increase the humidity rate of the room. These devices may also increase the number of negative ions in the air which is thought to enhance well-being.

Electric panel heaters

Electric panel heaters produce infrared waves which provide a similar type of heat to sunlight. These heaters work by radiation but most also transfer some heat through convection. The downside of infrared panel heaters is that they heat up any objects surrounding them including furniture, walls and people, which may not provide the most comfortable sensation.

Aluminium panel heaters powered by heating elements release what is referred to as far-infrared radiation while halogen heaters produce near-infrared radiation. Another disadvantage of these heaters is that they stop producing heat as soon as they are switched off. However, some models are equipped with a device used to store heat and release it over time like a storage heater.

Fan heaters

Fan heaters are essentially only used as additional heat sources but they can be used as the sole heating appliance in a bathroom as they are able to heat up small rooms in record time. These heaters are equipped with a fan system which releases heat generated by an electric element. Some fan heaters are fitted with ceramic heating elements which makes them more cost-effective to run.

Splash-resistant and often equipped with a timer, fan heaters may even be used alongside another heating device if you need to heat up a space in a hurry – this is especially useful for bathrooms.

Storage radiators

Storage radiators offer the most cost-effective option. The energy produced by these radiators can be stored in one of two ways: in a thermal fluid (i.e. an oil filled radiator) or by a solid material such as ceramic or stone in which the device is referred to as a dry inertia radiator. The heat itself is generated by a heating element before being stored in the core fluid or material.

Modern storage radiators

Many modern storage radiators feature two heating elements: one for the radiant panel and a core heating component powered by a second element. The advantage of these devices is that the outer panel heats up quickly and the core of the radiator retains heat for longer. While they are powered by electricity, they do not dry out the air. In fact, they produce a similar type of heat to central heating. These heaters are usually made of cast iron or aluminium. Cast iron is very good at retaining heat while aluminium heats up more quickly.

Economy 7 radiators

Economy 7 or night storage heaters are made of a highly thermally conductive material. They are so efficient at storing heat that the warmth that they gather overnight can be released throughout the next day without having to draw any more power. These storage heaters work on the same principle as other models in that they stock heat to distribute later on. The difference is that night storage heaters have a much greater storage capacity than the average storage radiator. Furthermore, these heaters help to save money as they store up heat during off-peak hours at night and release it at peak times during the day. The main drawback of these heaters is their weight and size.

The way in which storage heaters warm up and store heat will vary depending on the type of heating components they contain.

Thermal fluid

Some storage radiators are filled with a thermal fluid. These models heat up faster than dry inertia heaters and are also lighter. This fluid may consist of glycol, mineral oil or vegetable oil. Thermal fluids are, however, less effective at storing heat compared to solid materials. What's more, leaks can occur over time. Oil filled heaters are the most portable versions of these radiators.

Ceramic core radiators

Ceramic is better at retaining heat than thermal fluids but these radiators take longer to heat up. This material is used to create one of the most effective forms of storage heat technology as it is very good at retaining heat. The ceramic core is also great at releasing the heat gradually and evenly. These radiators offer maximum thermal comfort and significant energy savings as heat loss is minimal.

Soapstone core radiators

Soapstone is a type of metamorphic rock with high thermal conductivity. It is able to store a lot of heat over a small surface. These heaters are cost-effective as they continue to distribute heat even after they are switched off. Be wary of any heaters that mention reconstituted soapstone (which is generally mixed with cement) however, as this material does not have the same characteristics as pure soapstone and will not store heat as well.

Cast iron

Cast iron is an alloy of iron and carbon. A heavy material, cast iron is excellent at storing heat but is rather slow to heat up. These heaters will help to maintain air quality but they must be set up with an insulating material fitted behind the radiator itself. This is due to the fact that this type of device tends to heat up from behind and will heat up the wall.

Lava rock

As the name suggests, lava rock is a volcanic rock with high thermal conductivity. Lava rock stores heat very well and releases it for several hours after the device has been switched off. Also used in saunas for its thermal properties, lava stone is the best at releasing heat in relation to the area needed. A lava stone storage heater will take up less space than any other storage heater and will give off just as much heat.

Convector heaters

Convector heaters are not expensive to purchase but they will not heat up a room evenly. They rely on the circulation of cool air that is released as warm air when heated by electric elements. While they can reach an ideal temperature in just a few minutes, the warm air generated by convection will release dust into the air. These devices are therefore not recommended for those with allergies.

Electric panel heaters

The infrared waves from panel heaters heat up all objects around them meaning they can reduce any humidity in the walls and transfer heat directly to people. This type of heat spreads evenly and is quick to achieve, but there is no air movement. The main advantages of these heaters is the fact that they heat up quickly.

Electric panel heaters are, however, not recommended for use in bathrooms with tiles or in any room containing a lot of glazed surfaces, such as greenhouses or conservatories. In this case, it's best to use a halogen heater. These heaters are more direct, generally set up closer to people and are therefore less energy intensive.

Storage radiators

These radiators are slow to heat up but once they have reached their peak they will distribute heat constantly and durably, even after they are turned off. A modern storage radiator will usually be your most cost-effective option. They also provide the best solution if you are installing electric heating in a new building or overhauling your whole heating system. Up-to-date models are recommended for the most thermal comfort.

The aim of a thermostat is to control your heating system according to a set temperature. These days, most electric heaters come with thermostat control. However, the accuracy of the device will differ from model to model.

Mechanical thermostats

Mechanical thermostats are able to maintain a set temperature with an accuracy of 2°. These adjustable thermostats are best suited to convector heaters.

Electronic thermostats

Electronic thermostats maintain a set temperature with an accuracy of 0.5°. This is a great option as you won't waste energy and the temperature settings are also more accurate.

Digital thermostats

Digital thermostats are even more accurate and temperatures can be set with an error margin of just 0.1°.

Smart thermostats can be controlled manually using a built-in control panel or remotely using an app.

Smart control allows you to control your heaters with greater precision thanks to advanced functions such as a timer, open window detection, motion detectors, energy consumption data, and so on. You can also manage your energy consumption from each electric heater in a system. In addition to enhanced user comfort, smart control can allow you to make savings of up to 45% compared to use of a basic heater alone.

Wireless control allows you link up your heaters to create a centrally controlled heating zone using either Bluetooth or Wi-Fi.

This easy-to-use system allows you to control your heaters online.

In order to find the perfect heating solution, you should think about the type of heat transfer, heat distribution, heat-up times, temperature maintenance and air quality. If you have the budget, there's nothing stopping you from getting top-of-the-line smart heaters throughout the house! Otherwise, you should think about the specific heating needs of each room.

Hallways and spare rooms

Hallways and lesser used rooms (entrances, corridors, guest rooms, etc.) can be fitted with panel heaters. These heaters distribute heat evenly and quickly and will usually suffice for these spaces.

Living spaces

For rooms that you spend more time in (living rooms, offices, bedrooms, etc.) opt for greater comfort with a storage heater. If possible, go for a smart control system. As these rooms will be heated often, it is advisable to go for economy 7 heaters.

Bathrooms

A heated towel rail is a great option for a bathroom. These devices can even be combined with fan heater technology to heat up a smaller room in less time which will make getting out of the bath much more pleasant!

Choosing a heater for your room type

If you want thermal comfort, you'll need an efficient heating system that meets the requirements of your home. There are a few different criteria to consider:

• Heating quality: radiation vs. convection.

• Air quality: depends on the type of heat transfer; convection dries out the air.

• Temperature control: an over- or under-heated house on a daily basis will prove unpleasant; heaters should be quick to heat up and distribute heat evenly.

It's important to choose the right power rating for your electric heater or radiator. This is given in watts (W) or kilowatts (kW); 100 W= 1kW.

Wattage is linked to the surface area of the room which is indicated in square metres (m²); this is calculated by multiplying the length and width of a room. The power rating can also be referred to in terms of volume in cubic metres (m3) and is calculated by multiplying the surface area (m²) by the height of the room (h). Calculating the correct wattage for your heaters is important for your comfort as well as your wallet!

How to calculate heating power

The power rating of your heating system will also depend on:

• the temperatures over the winter where you live (i.e. it will be colder in regions of high altitude);

• the quality of your home's insulation;

• the desired average temperature;

• the volume of the rooms to be heated.

Power rating according to surface area or volume

In order to calculate the right power rating for your electric heater, you have several options:

• 100 W/m² or 0.4 kW/m3 for well-insulated homes;

• 70 W/m² or 0.28 kW/m3 for very well-insulated homes;

• 60W/m² or 0.24 kW/m3 for households with low energy needs.

If your ceilings measure over 2.5 metres, calculate your wattage based on room volume rather than surface area.

Exposure and location

• Add an extra 5 to 10% to your calculations for homes with large glazed surfaces and/or north-facing properties.

• Add an extra 10% to your calculations for every 500 metres of altitude.

Why choose two electric heaters over one?

No matter which calculation method you go for, if the room measures over 30 m², opt for two electric heaters for better heat distribution.

The majority of heaters are rated 500 W, 1,000 W, 1,500 W, and so on. It is better to overestimate your energy needs than underestimate them. If you have any doubts as to the quality of your insulation, you can get an Energy Performance Certificate and take measures to improve the energy efficiency of your home. A properly insulated home will considerably reduce your energy bill.

Heated towel rails work to heat up your bathroom and dry your towels at the same time.

Their large surface area means that they can heat up your room quickly and evenly. Manufacturers offer a range of different designs – from round to flat bars, there's something for everyone! Wall-mounted electric towel rails are generally quite good at retaining heat and may be equipped with solid heating components or thermal fluid. Some heated towel rails are fitted with a fan to heat up more quickly. A great alternative to traditional heaters, these devices have become more or less standard in most modern bathrooms.

Regardless of whether they are portable or fixed in place, electric heaters can be equipped with a range of options to improve safety, enhance user comfort and help you save money:

• anti-mark system: heat is diffused from the front of the device only to prevent dark marks from forming on the walls;

• open window detection: your heater will automatically turn off if a window is left open;

• consumption data: allows you to keep an eye on your energy bill;

• motion detection: the temperature of the heater will change automatically if the room is occupied;

• smartphone control for easy programming;

• child lock protection: allows you to lock the controls;

• anti-tip protection: essential for portable oil-filled radiators and panel heaters;

• overheat protection;

• frost protection for secondary homes;

• remote control to control your heat settings at a distance.

Don't forget to keep an eye on your electric heaters. Programming your system to align with your heating needs can help you to save a lot of money.

The layout of your room may mean that you need to install a different type of heater. The most popular options include horizontal, vertical, baseboard and skirting board heaters.

Horizontal heaters

Electric heaters and radiators are generally installed horizontally meaning they are wider than they are tall. These models generally work with most rooms and are the most widely available on the market.

Vertical heaters

Vertical heaters are best suited to rooms where horizontal space is limited. However, they tend to have a maximum height of around 180 cm.

Baseboard heaters

Baseboard heaters are designed for spaces that are very limited in height. They measure up to around 40 cm in height.

Skirting board heaters

Skirting board heaters are installed at the same height as your skirting boards and generally won't be any taller than about 20 cm.