High Quality Content by WIKIPEDIA articles! A cooling or heating water distribution system is in balance when the flow in the whole system (through the component terminal lines, distributing lines and main distributing lines) corresponds to the flow rates that were specified for the design of the system. If the correct balancing of the system is not established, this will result in unequal distribution of the flow so that there will be a surplus effect in some of the terminals, whereas the effect will be inadequate in others. The result of this will be that the wanted heating/chilling will not be ensured in all parts of the installation. In practice it is not possible to make a correctly balanced system by manipulation of the piping or alteration of the pipe dimensions only. Only a correct set of balancing valves can ensure the correct distribution of the flow in the system.