There was a craze on YouTube a few years ago for videos demonstrating a supposedly remarkable candle-powered room heater. You could make one yourself from two inverted clay flower-pots held together by a central threaded metal rod with two nuts acting as spacers. Light a ring of candles underneath and the flower pots would trap and distribute the heat.
Somebody well up in science asked how was it possible to amplify the heat from the candles, as by the principle of conservation of energy you can't get something for nothing - you'll only get precisely the same amount of heat energy as you do when burning the candles on their own without the flower pots. In other words, not very much. This is true, but what the contraption actually does in to convert one form of heat to another. Normally a candle produces hot air, convected heat, which rises straight up to the ceiling, which is why you see good light but feel very little heat. The flower pot device traps the convected heat, converting it to radiated heat. Anyone sitting next to the contraption will feel warmed by the radiated heat waves.
In practise, the candle-heater warming effect is minimal, but the same principle is used in mains-electric infra-read panel heaters. These are great for heating a small room, such as a home office. For example, previously I myself heated my 12 ft * 8 ft attic office with a 2kW convector heater. Now I use just a 300 watt infra red panel heater attached to its sloping ceiling. Just as effective, but only one seventh of the cost! The reason is simple. Convectors produce hot air which rises to the ceiling. The hot air gradually accumulates downwards to fill the lower levels of the space. Infra red panel heaters in contrast beam heat rays straight at you, so you instantly feel warmer. And the more gentle heat of the infra red panel heater has the advantage of being less soporific than the typical high-powred convector heater.
A word of warning. Because infra red heaters rely on proximity to the object needing to be warmed, they are much less effective say placed on the ceiling of a large living room. They are really at their best in smaller spaces, within three to four feet of the objects and people they are supposed to be heating.
And talking of heat, why not take a look at this novel, an international literary prize quarter-finalist, from my sponsoring web site:
