This European Standard specifies requirements, test method and acceptance tests for thermal performance of mechanical draught series cooling towers. This European Standard is applicable to series type wet cooling towers as defined in 3.1. The acceptance testing covers the verification of the thermal and hydraulic performance data of the cooling tower selected from the product line (see 3.1) and specified in the contract between the supplier and the purchaser. If these tests are required then this should be recognized at the time of the contract, as additional fittings, and preparations for the test may be required. A methodology to calculate the test tolerance is included in this standard. The contract should specify whether this methodology shall be used for the assessment of the test results or not. Legal and commercial consequences that might result from achieving or not achieving the contractually agreed performance are not part of this European Standard.