EN 15255:2007

Foreword
Introduction
1 Scope
2 Normative references
3 Terms, definitions, symbols and units
  3.1 Terms and definitions
  3.2 Symbols and units
  3.3 Subscripts
4 Basic assumptions
5 Data requirement
  5.1 General
  5.2 Climatic data
  5.3 Descriptions of the envelope elements
      5.3.1 General
      5.3.2 Boundary conditions
      5.3.3 Heat transfer coefficients
      5.3.4 Geometrical and thermophysical parameters
            of the room envelope
  5.4 Cooling system device
      5.4.1 General
      5.4.2 Convective device
      5.4.3 Cooled surface device
  5.5 Classification of the cooling load calculation
      method
6 Report of the calculation
7 Validation procedures
  7.1 General
  7.2 Reference room
  7.3 Climatic data
  7.4 Test cases
  7.5 Parameters to be calculated
  7.6 Test results
Annex A (informative) - Example of calculation method
        based on a simplified model
      A.1 Introduction
      A.2 Calculation of internal air and operative
          temperatures for a given value of applied
          cooling power
          A.2.1 Presentation
          A.2.2 Determination of the air and operative
                temperatures
          A.2.3 Terms in Equations (A.1), (A.2), (A.3),
                (A.4) and (A.5)
      A.3 Calculation of internal temperatures and required
          cooling power
          A.3.1 General description
          A.3.2 Calculation procedure for control on
                air temperature
          A.3.3 Calculation procedure for control on
                operative temperature
Bibliography

This European Standard sets out the level of input and output data, and prescribes the boundary conditions required for a calculation method of the sensible cooling load of a single room under constant and/or floating temperature taking into account the limit of the peak cooling load of the system. It includes a classification scheme of the calculation method and the criteria to be met by a calculation method in order to comply with this European Standard.The purpose of this European Standard is to validate calculation methods used to:evaluate the maximum cooling load for equipment selection and cooling system design;evaluate the temperature profile when the cooling capacity of the system is reduced;provide data for evaluation of the optimum possibilities for load reduction;allow analysis of partial loads as required for system design, operation and control.The validation procedure is used to check the room sensible heat balance model, taking into account:the external surface heat balance;the conduction through the building envelope;the effect of the thermal mass of the structures;the internal surface heat balance;the air heat balance;the heat balance solution method.All other aspects are given either by fixed boundary conditions or by input data and are not in the focus of the model validation. It is assumed that for all these other matters e.g. embedded heating and cooling systems, prescriptive models have to be used according to existing European Standards.Informative Annex A gives a simplified method for cooling load calculation.