The term radiant heating has a few different meanings when it comes to central HVAC for homes. The general meaning of radiant heating is a way that heat moves: waves of heat radiate off a hot object, and those move through space without heating the air until the waves meet another object and heat it. It’s the feeling you get from the pavement on a sunny day, or when you place your hand near a hot plate.
Radiant heating also refers to types of home heating systems that use this method of heating. Most radiant heating systems use a boiler to circulate water to points in the house, raise the temperature of those objects, and send heat into the rooms. Radiant heating systems can use radiators, baseboard heaters, or in-floor pipes at the terminal points that radiate heat into the room.