"Unbalanced loopfield flows can rob your loopfield capacity and produce unexpected system performance degradation." I recently saw this statement and I can't help but think that this is what encourages the use of balance valves on each supply and return in multiple group loop fields. Frankly, I don't believe that the penalty of imbalance is worse then the penalty of imposing a permanent extra pressure drop on the loop field and the resulting extra pump energy.... If the length of supply & return pipes is causing a balance concern then reduce the diameter on the closer groups and create better balance while also saving money and pump energy. I want to challenge the geothermal community to quantitatively support or dispute the use of balance valves. I look forward to a interesting discussion.