[neltnerb]

From context I can't tell if they mean the heated coils in a heat pump head, or somehow connecting to a traditional radiator.

In older homes there isn't necessarily HVAC at all and instead there are actual radiators. I've lived in two like that, there is just no forced air to rooms.

[CalRobert]

Yeah, European homes seem to have a love of radiators that I don't really understand; I hate mine. Ugly and huge.