Radiant heating is a technology for heating indoor and outdoor areas. The sun is an obvious example of radiant heating. Radiant heating can be used anywhere. For example, a device used for radiant heating can be used wherever you feel the need to have some extra heat. However, the sun has radiant heating all the time regardless.

Usually heating is done by passing air over the hot engine so no extra fuel (gas/petrol) is used.

because.

Yes, there are currently people who do have underfloor heating in their homes. Many people don't want to worry about walking on the cold bathroom and kitchen tile in the winter months and pay extra for underfloor heating for this reason.

To decrease eddy currents in the core which result in heating / extra losses. The thinner the laminations, the more effective this is.