Pipe spacing: 10, 15 or 20 cm
Spacing is the distance between neighbouring pipes. The closer they are, the more heat the floor gives off at the same water temperature, but the more pipe and loops you need.
| Spacing | Where it is usually used | Pipe per m² |
|---|---|---|
| 10 cm | Bathrooms, rooms with large windows, edge zones | 10 m |
| 15 cm | Bedrooms, living rooms, kitchens | 6.7 m |
| 20 cm | Storage rooms, rooms with low heat loss | 5 m |
Heat pumps: lower temperature, closer spacing
A heat pump works most efficiently with a low flow temperature, around 30–35 °C. For the floor to give off enough heat at that temperature, 10–15 cm spacing is the usual choice rather than 20 cm.
Edge zones by windows
Heat loss is greatest along outside walls and large windows. Under EN 1264 the pipes in a strip up to 1 m wide along them can be laid closer, for example every 10 cm, with 15 cm in the rest of the room.
How to decide
- The exact spacing follows from the room's heat loss, which a heating designer works out.
- Without that calculation, 15 cm is the usual choice for living spaces and 10 cm for bathrooms.
- One spacing for the whole house makes fitting easier, but does not always give the most even warmth.
- Going from 15 to 10 cm takes about one and a half times as much pipe and as many loops.