The internet-based electric heating specialists at Electric Heating Expert have something to say about claims of energy efficiency that are made in their industry, and the laws of physics are on their side.
Much has been made of the energy-saving properties of some types of electric heating. Most recently infrared heating has been said to be the most efficient of all.
Well, despite what you might read in some ads, the laws of physics still haven’t changed.
The fact of the matter is that all direct-acting electric heating appliances are 100% efficient. This includes radiators, panel heaters, and the newly acclaimed infrared heaters. One unit (or kilowatt) of electrical energy always produces an equal one kilowatt of heat output.
Though there are claims that some new infrared heating panels can produce as much heat as a radiator, but with less electricity, there’s no evidence to support them. Improving upon 100% efficiency in direct-acting electric heating would be a miracle – a technology that would re-write the laws of physics.
There are two methods of heat transfer commonly used in electric heating – convection and radiation. Convection is the transfer of heat energy through the air that circulates within a room. Radiation is the direct transfer of heat energy to people and objects.
Whilst infrared heating panels produce only radiant heat, electric radiators produce heat through a combination of both radiation and convection. The heating effect produced by electric radiators is just the same as you’d expect from a conventional boiler-fired wet radiator system.
Recently some manufacturers of Infrared heating panels have claimed energy savings of 50% when compared to other forms of electric heating. The proposition is that a 1.0kw infrared panel can be used to heat an area that would otherwise require a 2.0kw electric radiator. Although this claimed 50% energy saving may seem plausible to some, basic physics dictates that the 2.0kw radiator will produce twice as much heat as the infrared panel.
There are other flaws. Infrared heating panels emit radiant heat only, which is directional. The infrared waves travel in straight lines and are absorbed by people and objects. To feel the warmth you must be in front of, or beneath, an unobstructed infrared panel. In most normal homes there will be a number of cold spots within each room. To counter this, more heating panels must be installed – significantly increasing both the energy usage and the initial purchase and installation cost.
Where even the most basic electric radiator can regulate its energy consumption through thermostatic control, an infrared heating panel must continue to draw its full wattage capacity for the duration.
Once a room is up to temperature, a thermostatically controlled electric radiator uses energy intermittently, and in some cases, proportionally. The electricity required relates directly to the air temperature, so in a well-insulated room that has comparatively little heat loss, a radiator may only need to draw 30-40% of its full wattage capacity to maintain a set temperature.
An Infrared heating panel must draw power continuously. As radiation heats just people and objects – not the air – a thermostat or temperature sensor becomes redundant. Not only this, but if the infrared panel was to switch off even momentarily, the heating effect would be gone, and people in the room would quickly feel cold.
Although it’s hard to find a place for infrared heating panels in most home environments, they can be useful in some applications. Traditional churches, for instance, are impossible to heat fully due to the sheer size, the vaulted ceilings and the lack of insulation. Where the occupants typically remain seated, infrared panels can be suspended overhead and the directional radiant heat beams down from above.
A good analogy when considering infrared heating panels for home use is to consider them as desk lamps. Instead of lighting an entire area, just the work station is lit. This can be beneficial in some instances, but most of the time a full primary heating system is what’s really required.
Tony Renshaw, Managing Director of Ecopower Heating, commented: “Modern radiators are, in my view, still the best electric heating solution. Our domestic and trade customers choose them because they’re easy to install and reliable, and they offer an excellent level of control and comfort. They can be used to heat large and small properties very effectively – just as any primary heating system should.”