Water based surface embedded heating and cooling systems

BS EN 1264-2:2021 pdf free.Water based surface embedded heating and cooling systems Floor heating: Methods for the determination of the thermal output using calculations and experimental tests.
9 Test procedure for the determination of the thermal output of systems that cannot be calculated in accordance with Clause 6
For constructions which do not correspond to the basic construction of the types A, B, C or D. or in case of dimensions or material data outside the scope of the calculation method, the specific thermal output shall be determined by testing (experimentally) as follows.
A test sample consisting of at least three heating pipes, with the pipe spacing to be tested, in accordance with the system design of the floor heating to be investigated is positioned in the testing equipment according to Figure A.6. The size of the test sample shall be appro,dmate 1 m 1 m in agreement with the test laboratory. It shall cover preferably three-pipe spacing. In Figure A.6 the cooling plates simulate the room above the floor heating system (see Figure A.6, key 1), I.e. the temperature of the heated room 8, and the room below (see Figure A.6, key 4). For the cooling plates the construction according to Figure A.7 is recommended consisting of panel radiators with flat tubes in which disconnecting points realize the appropriate cooling water flow. The cooling plate shall be at least of size 1 m x 1 m. The upper plate shall exert a weight force of (450 ± 50) N during measurements. The thermal transfer resistance 1/a at the floor surface is simulated by the heat transfer layer (see Figure A.6, key 2).The two lateral heating pipes serve as a protection field to enable the optimum undisturbed temperature field around the central pipe. The thermal transfer resistance 1/a at the floor surface, given by the basic characteristic curve, is replaced by the thermal conduction resistance s/A of the heat transfer layer of equal magnitude (mean value):The tolerance on the value s/Ais 0,01 m2. K/W.
In the case of not feasible values of the measured temperature field caused by inhomogeneity of the screed, another part of the surface shall be taken.
Because of the fact that the temperature drop of the sample t9V R is very little and the fact that the temperature measurements shall be carried out in the undisturbed area around the central pipe no variation is necessary depending on the laying system (spirally or meandering).
The explanations above refer to the most usual case that the floor heating system is characterized by the repetition of the pipe spacing. The test sample in Figure A.6 which is symmetrical with respect to the central pipe is based on this fact. If another dimension characterizes the system the procedure has to be adjusted.
At first the test is realized for RB =0.
If it is not possible to set the temperature difference ( 9pmax — t9) exactly to 9 K, a value slightly below and a value slightly above 9 K shall be set and the results used to formulate a mean value.
Into this field of characteristic curves, also the limit curves in accordance with Formula (19) are entered. These characteristic curves give for RAB = 0 the standard specific thermal output qN and the associated standard temperature difference LI’N in accordance with 6.5. Further shall be documented the values of the limit specific output qG and the associated limit temperature difference ‘9HG depending on the remaining above mentioned values RAB in accordance with 6.5.
The tested system shall be identified by a technical description in accordance with Clause 5. These documents shall contain all dimensions and materials which influence the thermal properties. The results are valid only for the tested system. If any change is made by the supplier of the system which affects the principles of the thermal testing, a new test shall be carried out.
11 Test system
11.1 General
The test should be conducted by a test laboratory which is accredited according to EN ISO/IEC 17025. The laboratory takes part at all inter-comparison tests.
The test system consists of the following components:
— Computer system including the software to calculate the specific thermal output (field of characteristic curves and limit curves) according to Clause 6 of this document;
— Test equipment for the test procedure according to Clause 9 of this document;
— primary and secondary master sample;
— Constructional conformity: The participating laboratory shall state the conformity of Its test equipment to this document;
— Software conformity: The participating laboratory shall state the conformity of its software to this document.
11.2 Master samples
The construction and the materials of the master samples used for the test equipment of Clause 9 are shown in Figure A.9. The primary and the secondary master sample are of the same construction and materials. The laboratory shall equip itself with the master sample 2. Master sample 1 will be circulated among the laboratories participating at the test system. The manufacturing process has to ensure that for all samples the materials and the dimensions correspond correctly. This shall be verified and documented in a complete report. It shall be kept available for any further check.
The purpose of the master samples is as follows:
a) to verify if the reproducibility of test values among test laboratories is within the limits set by this document;
b) to establish a common basis for all test equipment to verify that the repeatability of test values in each test equipment is within the limits set by this document.
11.3 Verification of test equipment
All test equipment shall be verified for:
Reproducibility precision of the test methods:
The reproducibility shall be proved by the test laboratory using the primary master sample. The results of the tests carried out with the test equipment in accordance with Clause 9 shall be within the tolerance Sm = ± a1 % (determination of a see 11.4) of the values qNMS and = 0.15). The temperatures shall be measured over a width of one pipe spacing. The test laboratories have to prove the reproducibility in periodical tests.
Repeatability precision of the test methods:
The repeatability shall be proved by the test laboratory using its own secondary master sample. The tests shall be carried out periodically in a distance of 12 months. The results of the tests carried out with the test equipment in accordance with Clause 9 be within a tolerance range s0 = 2 %. At the starting of the test equipment three consecutive measurements shall be carried out to prove the fulfilment of the above requirements.BS EN 1264-2 pdf free download.Water based surface embedded heating and cooling systems