![]() The reason is that flow deficits may occur in some of the interior circuits. ![]() ![]() The reverse return loop provides each circuit with an equal length of distribution pipe therefore, the high drop AHU coil becomes the index circuit.Ĭaution: Direct return, proportionally balanced systems are not recommended for variable speed pumping systems. It also requires about 30% more distribution pipe. Reverse return provides equal length distribution piping for all coil circuits and, in theory, requires only minor adjustment of the manual balancing valves. When proportional balancing is complete, the design GPM is achieved by trimming the pump impeller or throttling the pump balancing valve.Īs an illustration, one major circuit has piped direct return the other reverse return. In the typical layout, the index circuit is highlighted. Proportional balancing strives to have all circuits with pressure drop equal to the index circuit which already has the most loss. This method is preferred by most designers for constant speed systems. Installation, Operation, and MaintenanceĪccusetter Manual Balancing Hydronic System Balancing with Calibrated VenturisĪSHRAE recommends that manual balancing valves be placed on the coils, risers, branches, and pump discharge so that the system can be proportionally balanced.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |