BS EN 1264-2 pdf free download
BS EN 1264-2-2021 pdf free download.Water based surface embedded heating and cooling systems Part 2: Floor heating: Methods for the determination of the thermal output using calculations and experimental tests.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1264-I apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/ 4 Thermal boundary conditions
A floor heating surface with a given average surface temperature exchanges the same thermal output in any room with the same indoor room temperature (standard indoor room temperature i9). It is therefore possible to give a basic characteristic curve of the relationship between specific thermal output and average surface temperature that is independent of the heating system and applicable to all floor heating surfaces (including those having peripheral areas with greater heat emissions) (see Figure A. 1 in normative Annex A).
In contrast, every floor heating system has its own maximum permissible specific thermal output, the limit specific thermal output, q. This output is calculated for an ambient (standard) indoor room temperature i9 = 20°C. The other condition is the maximum surface temperature 8F,max 29 OC1 at temperature drop between supply and return of the heating medium a = 0 K. The maximum specific thermal output for the peripheral area will be achieved at a maximum surface temperature
8F,max = 35 0C2 and a = 0 K.
For the calculation and for the test procedure, the centre of the heating surface is used as the reference point for ‘9F max’ regardless of system type.
The average surface temperature 9F, m’ determining the specific thermal output (see basic characteristic curve) is linked with the maximum surface temperature. In this context, ‘9F.m < F, max always applies.
The achievable value ‘9Fm depends on both the floor heating system and the operating conditions (temperature drop a = — 8R’ downward thermal output q and thermal resistance of the floor covering RAB).
The calculation of the specific thermal output is based on the following conditions:
— the heat transfer at the floor surface occurs in accordance with the basic characteristic curve;
— the temperature drop of the heating medium a = 0; the extent to which the characteristic curve depends on the temperature drop, is covered by using the logarithmically determined temperature difference between the heating medium and the room IOH (see Formula (1));
— turbulent pipe flow: mH/dI > 4 000 kg/(h
— there is no lateral heat flow;
— the heat-conducting layer of the floor heating system is thermally decoupled by thermal insulation from the structural base of the building. The thermal insulation need not be directly below the system.
The aforementioned last condition does not concern the test procedure of Clause 9.
5 Documents for testing
The system supplier’s documents are taken as the basis for the determination of the thermal output. The following documents shall be provided:
— installation drawing (section) of the floor heating system, covering two pipe spacing, including the peripheral area and giving information on the materials used (if necessary, the test results regarding the thermal conductivity values of the materials shall be provided);
— technical documentation of the system.
This information shall contain any details necessary for the calculation of the construction customary on site. It shall be submitted to the installer in the same form.
With a member of the testing body present, a demonstration surface of approximately 2 m x 2 m is constructed to represent the actual construction used on site.
6 Calculation of the specific thermal output (characteristic curves and limit curves)
6.1 General approach
The specific thermal output q at the surface of a floor is determined by the following parameters:
— Pipe spacing T;
— Thickness s and thermal conductivity AE of the layer above the pipe;
— Thermal conduction resistance RB of the floor covering;
— Pipe external diameter D = da, including the sheathing (D = dM) if necessary and the thermal conductivity of the pipe AR or the sheathing AM. In case of pipes having non-circular cross sections, the equivalent diameter of a circular pipe having the same circumference shall be used in the calculation (the screed covering shall not be changed). Thickness and thermal conductivity of permanently mounted diffusion barrier layers with a thickness up to 0,3 mm need not be considered in the calculation. In this case, D = da shall be used.BS EN 1264-2 pdf download.
