Posted by Harold Kestenholz - Hydronic Network on January 09, 2000 at 12:00:32:
In Reply to: adjustments/settings posted by gordy on January 09, 2000 at 10:34:42:
Globe valves are not ordinarily installed in hot water heating loops to control flow rates; balancing valves are more commonly used. However, the temperature drop as determined by the use of a thermometer, from the beginning of the loop to the end of the loop in most installations should be no more than 20F. The loop(s) with a temperature drop less than 20F would be restricted to force water to the loop(s) with a temperature drop greater than 20F until the loops are balanced (with all loops open and flowing water.)
In properly designed multizone systems controlled by circulator relays or zone valves, there is less need to balance the system, as zone controls stop the flow of water when the heat is satisfied in a zone, forcing more water to the other open loops.