Kirchhoff's loop rule (otherwise known as Kirchhoff's voltage law (KVL), Kirchhoff's mesh rule, Kirchhoff's second law, or Kirchhoff's second rule) is a rule pertaining to circuits, and is based on the principle of conservation of energy.
ECM stands for Electronically Commutated Motor. Basically, circulator pumps with ECM motors offer intelligent speed control. Speed-controlled pumps automatically adjust their output to changing demand, whether it be due to outside temperature, level of sunlight, overall activity, and other heating sources. The benefit of having a more efficient ECM motor pump is substantial energy savings, which directly relates to cost savings.
An impeller is a rotating component equipped with vanes or blades used in turbomachinery (e. g. centrifugal pumps). Flow deflection at the impeller vanes allows mechanical power (energy at the vanes) to be converted into pump power output. In accordance with EUROPUMP TERMINOLOGY and DIN 24250, a distinction is made between counter-clockwise and clockwise impellers, as viewed in inlet flow direction.