Are Infrared panel heaters a good way to heat a room?
Posted by Alex Barrett on 9 May 2017 at 2:50 pm
Infrared panel heaters are a relatively new way to heat your house. They work very differently to radiators, and have some advantages when it comes to energy efficiency.
Infrared panel heaters use radiation to heat the room instead of convection. This means that they deliver heat directly to people and furnishings rather than trying to heat the entire space. Electricity is expensive, so electric heating is often considered an uneconomical option, but by transferring heat more efficiently panel heaters can provide a good alternative to conventional central heating systems.
So what is the difference between convection and radiation? And what are the advantages of one over the other?
Heat always moves from hotter objects to colder ones. There are several ways in which heat can be transferred from one place to another. The most common are conduction, convection and radiation.
- Conduction primarily occurs through solids. Thermal energy is passed from one atom to another, and so moves rapidly through an object. Some materials, such as metal, conduct heat very efficiently. This why the outside of a radiator quickly warms up when hot water is pumped through it. Other substances transmit heat much less efficiently, and so make good insulation.
- Convection is the movement of heat through a fluid, such as air or water. When a fluid becomes hot its density decreases, this is why hot air rises. When it cools down again it becomes denser, and sinks. This sets up a circulation, and heat is moved from one place to another by the moving fluid.
- Radiation is the transmission of energy by electromagnetic waves. Heat is primarily transmitted by photons in the infrared range of the spectrum. These carry the energy from its source, and deliver it to any object which absorbs them. This means that radiation can pass through any transparent medium, including a vacuum.
Most central heating systems rely on convection to distribute heat. Despite their name radiators warm up the air around them, which circulates through the room. They emit some thermal radiation, which is why we can feel heat coming off them. However this isn’t their primary purpose.
Infrared panels rely on radiation, which makes them quite an efficient heating system so long as we do not try to use them in the same way as a normal radiator. Rather than heating the air an infrared panel delivers heat directly to the occupants and furnishings of the room. Anyone sitting in front of a panel will feel warm, even if the air around them is still fairly cold. This means that much less electricity has to be used than if the entire volume of the house has to be heated in order for the occupants to be comfortable.
This means that infrared panel heaters are particularly effective in older buildings which have draughts or poor insulation. Lack of insulation makes a conventional heating system massively inefficient. The heat produced by the boiler is constantly lost through the fabric of the building. This isn’t a problem for infrared heaters since the heat is delivered directly to the occupants of the room. It is also absorbed by walls and furnishings, which store heat much more effectively than air.
Infrared heaters can be used to set up temperature zoning within a room, since only the area in line of sight of the heater receives energy. This can be an advantage in large and draughty rooms, particularly if you will be sat in the same place for long periods of time. Since the panels are standalone units, with no pipes, they can be positioned to fit the layout of the room, even being hung on the ceiling so that they point down at the people below.
The main strength of infrared panels can also be their largest weakness; they provide a directed heat source, rather than a space heating solution. This means that they are very reliant on line of sight. If you are directly in front of the panel you will feel warm, but once you switch off the heater or move to a different area you will be cold again.
This means that they work best if you plan to stay in the same area for a while, but aren’t as good if you are going to be moving around a lot. Infrared panels can’t be mounted in the same places as traditional radiators, since furniture will easily block the panel. Walls and furnishings will reemit energy for a short time after the heater stops running, but for the most part you will need to keep it on in order to feel warm.
- The Green Age: Heating Panels, 10 advantages of infrared heating panels
- Infrared4Homes: Infrared heating vs a gas central heating system, Why is radiant infrared heating so efficient
- Low Tech Magazine: How to keep warm in a cool house.
Image credit: VonHouse Ceramic Flat Panel Heater 450 W by Designer Habitat Ltd via Flickr
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