Standard UNI EN 1264

UNI EN 1264-2

UNI EN 1264-2:2013 is the part that characterises the product since it provides the tools to determine the performance of the radiant floor system.

This is the part of the standard that characterises the radiant floor product and compares the performance of the various floor systems available on the market. By performance is meant:

  • the useful heat output that can be supplied by the system
  • the heat loss of the system

Useful heat output is more commonly understood as the system‘s "performance" i.e. the capacity of a hot-water radiant floor to provide heat to a room.
By "high performance" we mean the radiant floor is able to provide higher heat output at the same water temperature or alternatively, the same output at a lower water temperature. It is advisable to install a "high-performance" radiant surface system to optimise heat generator performance. Designers can compare the available products and choose the radiant floor system that offers the "highest performance" by comparing the certified heat outputs according to EN 1264-2.

The manufacturer can declare the heat output of its radiant floor system using the calculation methods proposed by UNI EN 1264-2. Any characterisation of a radiant floor system must consider potential heat output as well as heat loss.

In order to perform an accurate product comparison we must compare not just the output of the radiant floor but also the heat loss which is calculated according to the algorithm that follows and is given in §8 of UNI EN 1264-2:2013:

where q is the useful output; ϑi is the temperature of the floor-heated room; ϑu is the temperature of the room below; Ro is the sum of the thermal resistances of the layers between the tubing and the room to be heated and Ru is the sum of the thermal resistances of the layers between the tubing and the room below. For the same building, the performance of the radiant system changes with the Rλ,ins value of the insulating panel used with the system.