What i dont understand is how it is efficient to deliver a constant 70 degrees heating pipe. There has to be some kind of boiler/trigger right?
The pipes are well insulated and apparently the energy loss quite manageable.
Depending on the specifics, that's often about 5x more efficient.
Counterintuitively - the "heat" source doesn't have to actually be hot. In theory as long as it's above absolute zero it can be used as a heat source to heat up the inside of your home. It's the same for cooling - even if it's hot indoors and really hot outdoors, you can still use a heat pump to make it even colder inside the hosue.