Standards for radiant systems

The UNI EN 1264 standard, which consists of 5 parts, is the

technical standard that defines all of the elements that make up

an underfloor, wall and ceiling system. This same standard pro-

vides the methods for calculating the emissions of these system

referred to in the preceding paragraph. Below we summarise

the key points, with particular regard to underfloor systems, in-

dicating the parts that can be helpful in designing and installing

these systems.

In addition to the aforesaid standard, we can add EN ISO 11855

which also consists of 5 parts that are similar to the previous

standard, but applies exclusively to

floor systems.

Finally, it is important that we mention UNI 11371 which, al-

though not speci

fically relating to radiant systems, covers them

as it relates to “Screeds for parquet and wood flooring” and is

particularly recommended in the case of wooden coverings:

•

Fixing to the slab underneath the radiant panels when the

screed thickness is under 30 mm;

•

A water vapour barrier that overlaps by 100 mm, turned

under the PE sheet of the perimeter strip, appropriately

sealed and with SD > 40 m, to be installed under the radi-

ant panels.

Functioning of the systems

Particular attention is paid to the thermal resistance of the insu-

lating layer placed between the system and the outside or the

underlying environment.

The Standard considers the insulating layer to be the one placed

immediately below the piping, even if resulting from the coupling

of two or more panels. The thermal resistances to consider are:

Underlying

heated

environment

Underlying

environment

unheated, not

continuously

heated or directly

on the ground*

Temperature of the underlying outside air

Outside design

temperature

T

d

≥ 0 °C

Outside design

temperature

0 °C > T

d

≥ -15 °C

Outside design

temperature

-5 °C > T

d

≥ -15 °C

Thermal

resistance

(m

2

·K/W)

0.75

*With a ground water level of ≤5 m, the value should be increased

1.25

1.25

1.50

2.00

Heated room -20°C

Therm. res. from 1.25 to 2.00

Heated room -20°C

Therm. res. 0.75

Heated room -20°C

Therm. res. 1.25

Unheated environment

Heated room -20°C

Therm. res. 0.75

Heated room -20°C

Therm. res. 1.25

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Underfloor Radiant Systems - Product Guide

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