First of all, in terms of heating area, only half of the chassis of the semi-circular heating constant temperature coaster is heating, which means that its heating area is relatively small and only some areas are heated. The whole circle of heating constant temperature coasters has heating elements on its chassis, which can heat the heat conducting plate at the bottom of the pot.
Secondly, from the point of view of heat source effect, the constant temperature coaster with half a circle of heat boils water slowly, because its heating area is relatively small and the heat transfer is uneven under the same power. The constant-temperature coasters with full-circle heating boil water faster, because the heating area is larger and more uniform, and the water can be heated to the set temperature faster.
In addition, the prices and functions of these two kinds of constant temperature coasters may be different. It is recommended to ask the merchant for detailed information.