EN 15316-2-3:2007

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols, units and indices
5 Principle of the method and definitions
6 Auxiliary energy demand
  6.1 General
  6.2 Design hydraulic power
  6.3 Detailed calculation method
      6.3.1 Input/output data
      6.3.2 Calculation method
      6.3.3 Correction factors
      6.3.4 Expenditure energy factor
      6.3.5 Intermittent operation
  6.4 Deviations from the detailed calculation method
  6.5 Monthly auxiliary energy demand
  6.6 Recoverable auxiliary energy
7 System thermal loss of distribution systems
  7.1 General
  7.2 Detailed calculation method
      7.2.1 Input/output data
      7.2.2 Calculation method
      7.2.3 Thermal losses of accessories
      7.2.4 Recoverable and un-recoverable system thermal loss
      7.2.5 Total system thermal loss
  7.3 Calculation of linear thermal transmittance (W/mK):
  7.4 Calculation of mean part load of distribution per zone
8 Calculation of supply and return temperature depending on
  mean part load of distribution
  8.1 Temperature calculation of heat emitters
      8.1.1 General
      8.1.2 Continuous control depending on outdoor temperature
      8.1.3 Continuous control with thermostatic valves
      8.1.4 On-Off control with room thermostat
  8.2 Effect of by-pass connections
  8.3 Effect of mixing valves
  8.4 Parallel connection of distribution circuits
  8.5 Primary circuits
Annex A (informative) Preferred procedures
 A.1 Simplified calculation method for determination of annual
     auxiliary energy demand
     A.1.1 Input/output data
     A.1.2 Calculation method
     A.1.3 Correction factors
     A.1.4 Expenditure energy factor
     A.1.5 Intermittent operation
     A.1.6 Monthly auxiliary energy demand and recoverable
           auxiliary energy
 A.2 Tabulated calculation method for determination of annual
     auxiliary energy demand
     A.2.1 Input/output data
     A.2.2 Calculation method, tabulated values
     A.2.3 Monthly auxiliary energy demand and recoverable
           auxiliary energy
 A.3 Simplified calculation method for determination of annual
     system thermal loss
     A.3.1 Input/output data
     A.3.2 Calculation method
     A.3.3 Approximation of the length of pipes per zone in
           distribution systems
     A.3.4 Default values of the outer total surface coefficient
           of heat transfer (convection and radiation)
     A.3.5 Approximation of [psi] -values
     A.3.6 Equivalent length of valves
     A.3.7 Default values for the exponent of the heat emission
           system
 A.4 Tabulated calculation method for determination of annual
     system thermal loss
     A.4.1 Input/output data
     A.4.2 Calculation method, tabulated values
 A.5 Example
Bibliography

This European Standard provides a methodology to calculate/estimate the system thermal loss of water based distribution systems for heating and the auxiliary energy demand, as well as the recoverable part of each. The actual recovered energy depends on the gain to loss ratio. Different levels of accuracy, corresponding to the needs of the user and the input data available at each design stage of the project, are provided in this European Standard by different calculation methods, i.e. a detailed calculation method, a simplified calculation method and a method based on tabulated values. The general method of calculation can be applied for any time-step (hour, day, month or year).Pipework lengths for the heating of decentralised, non-domestic ventilation systems equipment are to be calculated in the same way as for water based heating systems. For centralised, non-domestic ventilation systems equipment, the length is to be specified in accordance with its location.NOTEIt is possible to calculate the system thermal loss and auxiliary energy demand for cooling systems with the same calculation methods as shown in this European Standard. Specifically, determination of auxiliary energy demand is based on the same assumptions for efficiency of pumps, because the efficiency curve applied is an approximation for inline and external motors. It needs to be decided by the standardisation group of CEN, whether or not the extension for cooling systems should be made in this European Standard. This is also valid for distribution systems in HVAC (in ducts) and also for special liquids.