A water manifold is a section of pipe that has built in ports in it designed to distribute water. Water manifolds are regularly used in home plumbing. They are control centers that control how water is distributed to parts of the house. Newer homes use this type of system to save money, time and energy.
In the past, homes were generally constructed with copper piping, which was first used by the Egyptians over 5,000 years ago. Copper was ideal at the time because it was rigid and corroded slower then galvanized piping. Manifolds with PEX piping came on the scene in the late 1960s from Europe and with widespread use starting in the 1980s. PEX piping is a flexible piping made of polyethylene that can bend around corners without kinking.
Types of water manifolds you will see in home plumbing are interior copper manifolds or PEX manifolds used for hot and cold water distribution throughout the house. These manifolds are attached to shut off valves in case of line break or an emergency or if repairs need to made on a fixture. The other type of plumbing manifold that you would see in home use would be in the garden. This one would be used to distribute water to the sprinkler system. These manifolds are made of PVC plastic and usually have electronic valves attached to them so that the water comes on automatically.
A water manifold takes hot and cold water and distributes it around the house using flexible piping. The manifold is located in convenient and accessible location near the water heater. Water enters the manifold, which can be made of polyethylene or copper. From the manifold, the water is distributed to each individual fixture. The size of the manifold depends on the number of fixtures used. For example, if you have 4 sinks, a washer, dishwasher, two showers, two bath tubs and 3 toilets, you would need 10 outlets on the hot water manifold and 13 outlets on the cold water. Each outlet has a gate valve attached to it for easy shut off.
Use of manifold plumbing brings means PEX piping usage, which can be pulled like electrical wiring to each fixture. This cuts down the use of fittings to just two, one at the fixture and one at the water heater. The advantage means fewer leaks in the long run because leaks usually come from failed fittings. When copper is used, all the hot and cold water is on one line. So when more then one fixture is in use at the same time, the pressure can drop dramatically. With a water manifold installed, this will not happen because the PEX piping goes to each individual fixture. When a leak occurs in copper piping it is usually in fittings that are covered up behind walls and in ceilings this means it is hard to get to and can cost a home owners large amounts of cash to fix the leak. With a manifold and PEX piping, this will not occur. There are fewer fittings used and they are in places that are accessible to make repairs.
Soldering a piece of copper has to be done right or the fitting will fail. This process is very labor intensive. Copper prices are expensive. With a manifold system you use PEX piping. PEX piping is not labor intensive because there are less fittings, and PEX is joined by a mechanical means and does not use solvents or solder to join the fitting. In the end, PEX is 50% cheaper then copper to install because there are less fittings and the labor to install is cheaper.