Self-regulating or fixed-resistance floor heating?

From the series "Eco-friendly solutions and technologies—trends 2023"

Self-regulating heating, unlike the commonly used fixed-resistance cables, automatically adjusts the heating power along the length of the cable to the ambient temperature by responding to external heat sources.

Due to its design using a polymeric self-regulating element:

• it has no possibility of heating above the marked maximum temperature (it does not overheat, it can be safely wound or crossed),
• it can be cut or extended at will during installation,
• is very mechanically durable.
  
  

Self-regulating floor heating

© nVent | Raychem

This is important in specific situations.

Self-regulating systems, due to their more advanced technology, are a more expensive solution. In what situations does the type of cable matter? To begin with, let's compare the two types of systems:

ROOM ARRANGEMENT

Many users, when buying an underfloor heating system, forget about the need to plan very carefully the arrangement of the room, i.e. kitchen or bathroom cabinets. Fixed-resistance systems heat with full power over the entire surface—in obscured areas the heat accumulates, so the system may fail (overheat the wire) or damage furniture or carpet on the floor. The self-regulating, intelligent nVent RAYCHEM T2Red system detects such zones on its own and limits the heating, and changing the position of furniture in the future is not a problem.

underfloor heating

© nVent | Raychem

TYPE OF FLOORING

Self-regulating cables can be laid under absolutely any type of flooring, including wood panels, carpet or linoleum. Fixed-resistance conductors can only be used under ceramic or natural stone tiles.

ADDITIONAL INSULATION

It is recommended to lay T2Red self-regulating cables in grooved Reflecta insulation boards, covered with a layer of aluminum. These ensure even heat distribution and prevent heat loss down the floor, reducing energy consumption. However, it should be remembered that this system is 13 mm thick—so it will be necessary to raise the floor level. In cases where there is no room for this, a good alternative is a fixed-top mat or heating cable, which can be laid in a layer of tile adhesive thanks to its slim thickness of 3 mm.

EU1077 Reflecta

© nVent | Raychem

T2Red self-regulating cable

© nVent | Raychem

Can electric underfloor heating be the main heat source in a new home?

Yes, electric floor heating can be the main and only source of heating. The solution is storage underfloor heating, which aims to reduce the cost of heating the house by using cheaper electricity in the second night tariff and eliminating alternative heating systems. It is an ideal solution in combination with a photovoltaic system or the use of energy from other renewable sources.

nVent RAYCHEM T2Blue 20 electric heating cable laid to the concrete layer

© nVent | Raychem

The system consists of an electric heating cable (for example, nVent RAYCHEM T2Blue 20) laid into the concrete layer, which acts as a heat accumulator, so it must be of sufficient thickness (usually 8-10 cm) to perform its function properly. The power of the installed system is in the range of 100 W/m² (gross)—160 W/m² net, depending on the building structure (heat loss). The installation should take into account the plans for future permanent construction—heating cables are laid over the entire surface, leaving aside the built-up zones. At the same time, it should be remembered that the system with higher power heats up faster, so it works for a shorter time, which in practice means comparable electricity consumption.

For more information, visit the company's NVENT THERMAL POLSKA Sp. z o.o. page on the PdA portal.