Most heating systems deliver heat into a room from a focused point, such as a forced-air vent or steam radiator, or a single side, such as a baseboard radiator. The adjacent area is typically the warmest place in the room.
However, as the heated air enters the room, it almost immediately begins to rise towards the ceiling, and only falls after losing much of its heat. That makes the air near the floor noticeably colder – 20 degrees or more – than the air at head level, five or six feet above the ground. The result: cold feet and hot heads. This effect is more pronounced in homes without excellent insulation and when it’s very cold outside.
By contrast, radiant heating systems heat rooms from the floors up, from the ceiling down, walls in, or some combination. The heated surfaces radiate heat in all directions and warm air at a relatively low temperature, transferring heat to other parts of the room at a uniform rate. This means less noticeable temperature contrasts within rooms, little to no vertical temperature stratification, and more comfortable rooms overall.
Hydronic systems particularly in-floor radiant or in ceiling radiant are considerably more comfortable than hot air systems and air conditioning.
Since large areas are typically heated or cooled in a radiant system perceived temperature is more effective in a radiant system as compared to a forced air system. In heating and cooling, draughts are avoided.
Hydronic heating and cooling is virtually silent indoors.