Green Plumbing

Answer: A - There is no hot water distribution system design known as “alternating grid.” All three of the other options are common hot water distribution system designs. A central core system has the water heater in the middle with piping emanating from it to fixtures in a spiderweb-like pattern. Manifold/parallel systems are newer; a manifold directs a dedicated line to each fixture. Trunk, branch and twig systems refer to the varying sizes of piping that decrease as the water flow approaches each fixture.