Any object, whether it be a person, furniture or even the walls of the room, are heated up in 3 different ways.
Here follows a very basic explanation.
Convective heat (i.e. ducted air or reverse cycle aircon) is where air is warmed up and physically blown throughout the room. A person feels the warm air being blown across them. This creates convection currents within the area, where the hot air rises to the ceiling and the cool air sinks to the bottom. The downside to convective heating is that you will need to heat the entire room from the top down, just for it to reach you.
Conduction heat is where a solid object is hot at one end and slowly the rest of the object heats up through the transfer of energy on a molecular level.
Radiant floor heating works by means of radiation.
All hot objects emit energy in the form of radiation. In the case of radiant floor heating, the object is the heating element within the floor. The heater cable warms the floor by conduction. The floor then radiates heat. In turn, all other objects within the space absorb this energy. This warms your feet up and transfers heat throughout your body and room.
A benefit of Coldbuster’s in slab and in screed heating options is that the heating element warms the entire space the cable sits in, creating thermal mass. This means that the slab or screed will retain heat longer and continue to radiate energy, even after the thermostat has been switched off!