This European standard is introduced in Europe to certify the output of all heat emitters for central heating systems. This standard Defines procedures for determining the standard thermal output of the heating appliances (radiators and convectors) fed with water or steam at temperatures below 248°F, supplied by a remote heat source. This also specifies the laboratory arrangements and testing methods to be adopted, the admissible tolerances the criteria for selecting the samples to be tested and for verifying the conformity of the current production with the samples. Guidelines for testing procedures and conditions are taken into this standard. All outputs are measured and certified for standard water and room temperatures. Standard inlet, return and room temperatures are: 167/149/68 , 194/158/68 and 131/113/68 °F. All alternative temperatures can be calculated according to realistic formulas and graphs. Also there will be tests performed on different products in the same product-range , this includes different flow rates and different cabinet heights. Due to the very strict structure of the test room, an exact reproducibility is obtained. There will be no extra addition to the measured results. All European manufacturers are obliged to participate in this testing procedure. A periodic recheck will be performed on a random selection of appliances. This standard ensures all users that the published heat outputs are officially tested and confirmed by an independent official laboratory.