When the calculation relates to a district cooling network, the physical properties of the water are adapted to the temperatures used in district cooling networks. Input and power data is adapted to take into account the fact that energy is removed at the production plants. When calculating a district cooling network, the consumers' return temperature must be stated as a parameter, along with power/flow.
You should be aware that “rules of thumb” from district heating distribution are not directly applicable. There are small temperature differences, and large water flows in these networks in relation to power!