Info
Hoe werkt het systeem, en welke methode past bij uw situatie?
Manifold and heat sources
The basis of every underfloor heating installation is a manifold, divided into a number of loops. For each loop, a pipe carries warm water out and circulates back to the manifold.
The heat source is not part of the installation itself. Heat sources can be a central heating boiler, district heating, a heat pump, or a hybrid combination. These split into Low Temperature (30–50 °C) and High Temperature (50–90 °C). Underfloor heating itself always operates between 28 and 35 °C — despite these low temperatures, the system delivers enough heating capacity by making optimal use of the floor surface.
The video shows a High Temperature heat source. Because underfloor heating works at low temperatures, the supply from an HT source is mixed with return water from the loops. This happens via the pump on the manifold, creating two circuits: the primary line from the source to the manifold, and the underfloor heating loops. Both circulate independently.
The number of loops is determined by: surface area, primary or supplementary heating, insulation value, pipe diameter, the presence or absence of an underfloor heating pump, and any zone control.
Installation methods and patterns
The installation method varies per project and falls into two categories: wet construction and dry construction.
In wet construction, a screed of sand-cement or anhydrite is poured over the underfloor heating pipes. Is there already a screed of at least 30 mm? Then it can be milled in. Is there no screed yet? Then the pipes are bound to steel mesh. Where the subfloor cannot be insulated from below, tacker or stud plates offer a solution — these are installed on top of the subfloor. After installation, the screed is poured by a third party.
Dry construction is the solution for structures with limited load capacity or build-up height. The floor is built up from gypsum fibre boards such as Fermacell or Knauf Brio — no water needed. After screwing and gluing, grooves are milled for the pipes.
The spacing between pipes determines the heating capacity. By default they are laid 10 cm apart. At cold bridges such as sliding doors, the pipes are placed closer together — known as edge zones. In rooms with lower heat demand, such as the hallway or toilet, they are spaced further apart. If a room already has other heating, this counts as supplementary heating.
The pipes are preferably laid in a spiral pattern. This gives the most even heat distribution. A serpentine pattern would create cold patches where the return pipe runs.
