Home » BIM and Energy » How do Radiant Heating Panels work and which type to choose?

Radiant heating

How do Radiant Heating Panels work and which type to choose?

Radiant heating panels offer many advantages in terms of thermal comfort and energy savings. How do they work and how are they designed?

Radiant heating panels represent a particularly ingenious and effective system – both functionally and energetically – for heating and cooling spaces. Their origin is ancient, but only in recent decades technology has enhanced them so much that they are preferred over traditional systems, both for the quality of the heated or cooled air by radiation and for the energy savings that result.

Let’s discover together how the radiant panel system works, what alternatives exist, and above all, what benefits it brings.

What are Radiant Panels?

Radiant panels are an alternative to more traditional heating and cooling systems and are terminals consisting of pipes through which hot water – at low temperature – or cold water flows.
The pipes are embedded in the structures of the enclosures where the panels are installed and are able to evenly distribute heat throughout the environment, optimally and uniformly, thanks to the principle of radiation.

This particular technology for heating and cooling environments is not so recent; the system dates back to the early 20th century. At that time, the system was studied and designed only for heating, and its operation involved the passage, in iron pipes, of high-temperature water. However, it was experimented that in this initial configuration, the excessive temperature of the water could cause discomfort to the users of the spaces, such as circulatory problems, headaches, increased pressure, and excessive sweating. For these reasons, the system was abandoned for a long time.

Today, however, the problem is largely solved; water flows in the pipes at low temperatures – about 25-45°C in the case of heating – and radiant panels have become a system for heating and cooling that is not only valid but also very advantageous in terms of environmental comfort and energy waste reduction.

How do Radiant Panels Work?

The operation of the radiant panel system is based, unlike traditional methods for heating and cooling environments, on the phenomenon of radiation. This phenomenon allows heat exchange between solid bodies without having to heat the air, giving the radiant system a high standard of energy efficiency, reflected in significantly lower operating temperatures compared to conventional systems.
Regarding operating temperatures, in fact, they range around:

  • 25/45°C in heating mode, against 55/70°C for conventional systems;
  • 15/18°C in cooling mode against 7/10°C for conventional systems.

Furthermore, the low temperature difference between the radiant surface and the air avoids annoying air movements that, as happens with traditional heating systems, move dust and cause heat loss.
Radiant panels represent a prefabricated and ready-to-install alternative, examples include:

  • gypsum radiant panels: developed for the installation of radiant systems in false ceilings for heating and cooling. Consisting of a gypsum board, a thermal activation formed by one or two pipe circuits, and an insulating layer, generally in polystyrene;
  • metal radiant panels: particularly suitable for heating and cooling open-space environments such as offices, lobbies, commercial spaces, airports, school buildings, etc.
Heated and cooled room with radiant panels on the ceiling, floor, and walls

Heated and cooled room with radiant panels on the ceiling, floor, and walls

How Many and What Types of Radiant Panel Systems Exist?

There are three types of radiant panel systems classified based on their position within the environment in which they are installed, namely:

  • radiant floor panels;
  • radiant wall panels;
  • radiant ceiling panels.

The radiant floor system is the most widespread due to its higher operating efficiency: hot air, being lighter, naturally tends to rise upwards.
Radiant ceiling and wall systems, on the other hand, are easily and quickly installable as radiant panels simultaneously create the false ceiling or false wall. The ceiling system also offers the advantage of reaching the operating temperature very quickly, while the wall system radiates heat more quickly, with uniform distribution throughout the height of the room.

Regarding the layout of the pipes, it can be done with constant or variable pitch, in forms such as:

  • single or double serpentine;
  • spiral.
Radiant panels piping layout

Radiant panels piping layout

The double serpentine and spiral layouts are preferable as they place the return pipe between the supply pipes, creating a uniform floor temperature.
In general, especially in the case of regular spaces, the spiral layout is always preferred as it limits pressure losses and ensures a more uniform heat distribution.

What are the Advantages of Radiant Panel Systems?

The benefits associated with the use of this system are many and can vary depending on the type of panel chosen, but all radiant panels share the following three advantages:

  • high thermal and living comfort: the radiant panel system is characterized by absolute silence and zero electromagnetic emissions;
  • energy savings: operating with a reduced temperature difference compared to ambient temperature, this system allows considerable energy savings. If we then consider the coupling with high-efficiency generators, such as condensing boilers, PDC heat pumps, and renewable sources such as solar thermal panels, the savings are truly high;
  • hygienic-aesthetic aspect: the absence of air movements prevents dust movement and therefore unhealthy air conditions, especially for those suffering from allergies, and at the same time, the invisible terminals allow maximum freedom of furnishing.

The adoption of radiant panels fits perfectly into the framework of sustainable construction, contributing to the certification of eco-friendly buildings and compliance with the highest environmental standards.
Thanks to their efficiency and low environmental impact, radiant panels are an ideal choice for new construction projects and renovation interventions oriented towards sustainability.

To best tackle this type of challenge, I recommend using:

  • a software for designing thermal systems, including radiant panel systems, directly in plan or in 3D. The software allows you to model a system starting from an architectural project created with a BIM authoring software and obtain the sizing of terminals, pipes, special pieces, and regulating valves, the verification of pump head and flow rate, and the recalibration of flows;