Hydronic Radiators and Hot Water Heating Systems
Hydronic radiators deliver heat through convection and radiation. Water is heated in a boiler and distributed by pipes to convectors. Air circulates from floor through heated fins of convectors. Warmed air rises by convection. At same time, convectors radiate heat directly into the room.
…………………………………………
Source:http://www.hometips.com/hyhw/comfort/45hydronic.html