ISO 11855-4:2012 allows the calculation of peak cooling capacity of Thermo Active Building Systems (TABS), based on heat gains, such as solar gains, internal heat gains, and ventilation, and the calculation of the cooling power demand on the water side, to be used to size the cooling system, as regards the chiller size, fluid flow rate, etc.
ISO 11855-4:2012 defines a detailed method aimed at the calculation of heating and cooling capacity in non-steady state conditions.