Most other electrical heating systems - including night storage heating - use heated convected air to warm a room. This is generally inefficient, unhealthy (especially for allergy sufferers) and expensive. Suka heaters copy the sun and use radiant heat which is healthy, very efficient and very economical. Remember in winter when the sun is shining and the air temperature is near freezing, your skin soon warms up when exposed to the radiant heat of the sun. In the alps skiers actually sunbathe without problems even though the air temperatures are low! Radiant heat warms up the walls and the furniture of your home as well as you and so only occasional top-up heat is required. A stone warmed by the sun will hold its heat far longer than a stone warmed by warm air!