What is infrared light?
Infrared light is the reason why we feel warm when the sun is shining in the middle of a wintery day. Conventional wisdom would suggest that if the air temperature were freezing, then you too would feel cold. However the infrared waves emitted by the sun travel unimpeded through space, and warm any object they hit, including your body.
The visible light spectrum – infrared
Infrared is a form of electromagnetic radiation that sits just beyond the red end of the visible light range of the electromagnetic spectrum. We often hear the word radiation and automatically associate it with being harmful, but in fact, radiation is just a process of energy emission. Just like visible light radiation, infrared radiation is 100% safe and even our own bodies emit infrared radiation (which is what allows search and rescue helicopters to find lost travelers at night for example).
Conventional space heating in homes
Conventional heating in the home works by warming up the air around you; for instance a radiator does most of its heating through convection currents (it also gives off small amounts of infrared radiation).
When the radiator warms up, it heats the air directly around it, which then expands and rises. As the hot air rises, it creates a vacuum behind it, which pulls colder air into contact with the radiator, causing it to heat up. As the hot air begins to cool down it drops down back to floor level. This cold air gets heated again and this process keeps repeating itself – this is known as convection heating.
Most conventional heating systems do emit some infrared waves. For example, if you have ever sat near an open fire, you will have felt the heat on your face. Then when you put your hand in front of your face, this stops the infrared hitting your face directly; instead you will feel your hands get warm. This is infrared.
Infrared heaters in the home
Infrared heating is a fairly recent addition to the domestic and commercial heating scene. It is emitted from the heater, which then travels unimpeded through the air until it hits an object. The object absorbs the radiation, causing molecules within it to vibrate, producing heat.
If the waves come into contact with humans, they will travel about an inch into the body providing a feeling of deep heat, but even if you are not directly in the way of the waves, any solid body will vibrate when the waves hit them, causing them to radiate heat back towards you.
Despite being able to purchase gas, oil and solid fuel infrared heaters, we suggest using electric infrared panels in the home, since you do not need to integrate any pipe work or fuel storage facilities when you install the panels. There are also no direct emissions associated with using the electrical panels (and if you use them in conjunction with solar panels you get 100% emission free heating). They also can be placed high up on the walls or the ceiling, so they will be easy to keep away from pets and children (they get about as warm as a standard radiator).
The electric panels come in numerous sizes and certain models can double up as mirrors. Since they have no moving parts, they operate in complete silence, which makes them ideal for bedrooms.
Energy savings from infrared heaters
Infrared heating works by heating the surface area of a room, rather than the volume (as is the case the traditional convection heaters), which means they are heating considerably less to provide the same amount of heat.
The following worked example compares a 600 Watt infrared heat panel and a standard 1500 Watt convection heater (like for like providing the same comfort of heat), providing heat up to 4 months of winter (November through to Feb) for 8 hours a day at a cost of £0.14 per kWh of electricity.
Infrared Heater Convection Heater
Energy rating 600 Watts 1500 Watts
Electricity units per hour 0.60 1.50
Thermostat savings 50% 80%
Total electrical units used 288 1152
Total cost £40.32 161.28
In addition, you are heating solid walls or objects with infrared radiation and these have a thermal mass, which means they retain heat and help keep the home cosy. Conversely, air has no thermal mass, so in the case of traditional convection-warmed rooms, when a door is opened, the hot air will quickly escape; requiring you to reheat the room to feel warm again. One brilliant factor in favour of these panels is the ability to provide the home with a fully-zoned property. Unlike central heating systems, the panels can be switched on in individual rooms using the thermostats. This means that heating is only fully used when required. If you think how much energy is wasted in rooms that do not need to be heated, such as guest bedrooms, this is a real benefit.
Electric infrared panels also only take about 30 seconds to reach full operating temperature and therefore are much more efficient at heating a space than conventional space heating heaters. The heat is also contained in the thermal mass of the room surfaces, as opposed to the heat. This means that it stays warmer for longer and draughts do not play as large a part when compared with convection heaters.
Infrared vs. other heating systems
Heating System Annual Cost
Gas central heating with zone controls £608
infrared with zone controls £804
Reversible air con with zone controls £881
Air-water heat pump with zone controls £977
Biomass £1,209
Electric convector heating with zone controls £1,332
Electric underfloor heating with zone controls £1,508
New electric night storage with automatic controls £1,734
Other advantages of infrared heating
Another major advantage of infrared heating is that unlike conventional heaters that just heat the air, infrared heaters heat the walls, which will mean they stay completely dry. It then builds up the thermal mass within the walls and the floors, which maintains the warmth and keeps it dry by reducing condensation. Therefore infrared heating helps prevent the spread of mould in the property.
In addition, conventional heaters warm the room by convection currents that circulate dust particles continuously around the home, however these convection currents do not occur with infrared heating, so for people who suffer from asthma, infrared panels can be the ideal solution.
Infrared heaters also will provide the optimum heating temperature within 30 seconds of being turned on. Since there are no moving parts, they make no noise; therefore they are ideal as a heating solution in bedrooms.
Benefits
Since infrared heaters heat solid objects in the home like walls, they prevent any moisture build up on these surfaces and so inhibit the spread of mould.
Fit and forget technology, very little maintenance required.
These heaters are emission free (i.e. no fuel is burnt in their operation) and if they are used in conjunction with renewable energy sources like solar PV, you are producing 100% clean heat.
The way these heaters heat a room is more efficient than conventional convection heaters so they are more cost effective to run.
Infrared heaters warm solid objects with a thermal capacity, therefore if a room is draughty or a door is opened, the solid objects retain the heat keeping the room warm.
Limitations
They cost about twice as much as traditional convection space heaters. However the saving difference made should mean that they pay back in a little over a year, and then you will experience savings on your energy bills.
To feel the true benefits of the heating panel, there needs to be no obstacles between you and the heating unit, which is not always easy to achieve.
(back to Infrared heating systems)