Standards for radiant systems

The following standards are applied when sizing and installing

ceiling and wall radiant systems:

UNI EN 1264 This standard is made up of 5 parts and is the

technical regulation that defines all the elements that make up

a radiant system built into the structures, fed with water, and

installed in the floor, wall or ceiling, for heating and cooling.

This same standard provides the methods for calculating the

emissions of these systems.

In this chapter we simply summarise the key points related to

what has been stated before in the part on environmental well-

being, and try to indicate the parts that can be helpful in de-

signing and installing these systems.

UNI EN 11855:2015 This standard applies to surface hy-

dronic heating and cooling systems built into the structures of

residential, commercial, and industrial buildings. The methods

apply to wall, floor, or ceiling systems, without air gaps around

them.

This standard overlaps with UNI EN 1264.

UNI EN 14240 This standard specifies the conditions and test

methods for determining the cooling capacity of cold ceilings,

that is, it defines the physical test used to calculate the thermal

performance in cooling. In fact, there is currently no specific

standard for ceiling units not built into the structures that de-

fines a method for calculating these performance levels. ISO

took a first step in this direction in 2016 when it published the

ISO 18566 standard, not yet transposed in Italy.

UNI EN 14037:2016 This standard defines the technical

specifications and requirements for prefabricated ceiling-

mounted panels, which provide an air gap between the struc-

ture and the heating unit, fed with water at a temperature of

less than 120°C.

It also provides indications for the physical tests for determin-

ing the thermal performance in heating and cooling, and so this

point overlaps with UNI EN 14240.

Insulating layers

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

lating layer placed between the system and the outside or the

adjacent 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

environment

unheated, not

continuously

heated or directly

on the ground*

0.75

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

Underlying

environment

heated

Outside design

temperature

-5 °C > T

d

≥ -15 °C

1.50

2.00

Temperature of the underlying outside air

Outside design

temperature

T

d

≥ 0 °C

Outside design

temperature

0 °C > T

d

≥ -15 °C

Thermal

resistance

(m

2

·K/W)

1.25

1.25

In relation to wall and ceiling systems, be careful:

The thermal resistance is not only that in the single insulating

layer behind the piping, but the thermal resistance of the en-

tire structure behind the piping is taken into account. The ther-

mal resistance values are the same as those in the table shown

above.

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

14

Ceiling and wall radiant system – Product guide

Tel. +39 0425 75 88 11