Today, however, crucial words used to describe these traditional topics have been stripped from an influential children's dictionary in favour of more 'modern' terms. Among the entries which have disappeared from the latest edition of the Oxford Junior Dictionary are disciple, coronation, empire, piglet and acorn. In their place come the likes of MP3 player, broadband, biodegradable, committee and celebrity.
A heat pump is a device that transfers heat energy from a source of heat to a destination called a heat sink. Heat pumps are designed to move thermal energy in the opposite direction of spontaneous heat transfer by absorbing heat from a cold space and releasing it to a warmer one. A heat pump uses a small amount of external power to accomplish the work of transferring energy from the heat source to the heat sink.
As it turns out, a heat pump can both heat and cool, and in some applications, it's preferred to separate heating and cooling systems. Simply put, a heat pump is a device that uses a small amount of energy to move heat from one location to another. Not too difficult, right? Heat pumps are typically used to pull heat out of the air or ground to heat a home or office building, but they can be reversed to cool a building. In a way, if you know how an air conditioner works, then you already know a lot about how a heat pump works. This is because heat pumps and air conditioners operate in a very similar way.