You may be perplexed, but more more length and cost will save you cost at the same time.
The usage of PEX lines in the hot water system improves the labor productivity tremendously, rather than using traditional plumbing approaches.
The linear feet of tubing is more than traditional plumbing lengths, but the overall cost is reduced because the labor is so simple, especially with production building. The two different PEX tube diameters used are ½” for showers and the washing machine and ⅜” for all others.
The PEX manifold works by sending hot and cold water into a port which sends the water out to each individual fixture. The previous images show how the manifold, along with visuals of connections to the hot water tank and outgoing PEX lines.
The design of the PEX manifold was purposefully chosen to reduce the amount of hot water wasted and maintain the EPA watersense requirement of 0.5 gallons of standing water in any pipe.
A manifold allows each terminal fixture to have it’s own direct source from the manifold, which means smaller diameters of PEX lines. With a smaller diameter tube, less standing hot water is left in the pipe after a fixture is used. The longest tube is 28.5’ of ½” line to a shower on the top floor, and this same line holds the most water with .26 gallons. The EPA watersense requirements are also all met with the gpm’s of each fixture.