BS EN 15255:2007

BS EN 15255:2007 - Energy performance of buildings. Sensible room cooling load calculation. General criteria and validation procedures

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.