Residential PEX Manifold Plumbing
PEX Tubing for Residential Plumbing Systems
I was asked earlier today if a hot water demand system would work with one of these new PEX plumbing systems that use remote manifolds.
Well the short answer is yes. You can basically use a hot water demand system with any hot water distribution system. The only criteria are that the cold water faucets are connected somewhere in the house to the inlet of the water heater, and the hot water pipes connect to the water heater outlet.
It doesn’t matter if it’s a tank type water heater, a tankless water heater, or a solar water heater, a good demand system will work with any of them.
What Is a Pex Manifold Plumbing System?
Pex is a modified polyethylene material that has good properties for use in water distribution systems. A PEX plumbing system uses PEX tubing including 3/8 inch, ½ inch and ¾ inch diameters.
Using PEX tubing allows you to use long continuous tubing runs between the source of hot water and the fixture without the need for elbows and other fittings. This keeps pressure drops to a minimum and reduces labor.
Typically PEX systems will have a main trunk line or lines connecting to manifolds. The manifolds normally have a shut off valve at each outlet so the individual piping runs can be turned off individually. 3/8 tubing is often used for the run from the manifold to the individual fixtures.
Advantages of PEX tubing
With such small diameter tubing the water velocity is high and so the hot water reaches the fixture more quickly than with a conventional piping system.
The low volume of water contained in the tubing results in a small conservation of water compared to conventional piping systems.
Other potential advantages include the ability to expand enough to absorb water hammer reducing the noise from suddenly turning off the water, and the ability to resist scale build up.
PEX tubing should not be exposed to sunlight and can’t be used where it will be subjected even to reflected sunlight.
Hot Water Pumps and PEX
Typical demand hot water pumps and systems would be beneficial for manifold type PEX systems in cases where the trunk line feeding the manifold was very long. In those plumbing layouts where the trunk lines are long, a demand pump can be connected between an outlet port on the hot manifold and an outlet on the cold manifold.
For “home run” type piping layouts, a demand hot water system would not be practical. You would need a pump for each run, and with the small tubing you would not be saving much water or time either.
Looped Plumbing with PEX
Looped plumbing, where the piping is looped from fixture to fixture when equipped with a demand hot water pump is the greenest solution. That way you can place a demand hot water pump at the end of the line, and get fast efficient hot water delivery at every sink. It will save a lot of water and it will be very energy efficient.
Tankless Water Heaters and PEX Plumbing Systems
There is no reason PEX tubing can’t be used with tankless water heaters. The hot water delivered by a tankless water heater is no different than the hot water delivered by any other kind of water heater.
In some cases PEX systems can benefit tankless water heaters since tankless heaters take a little longer to deliver hot water to the fixtures.
I was asked earlier today if a hot water demand system would work with one of these new PEX plumbing systems that use remote manifolds.
Well the short answer is yes. You can basically use a hot water demand system with any hot water distribution system. The only criteria are that the cold water faucets are connected somewhere in the house to the inlet of the water heater, and the hot water pipes connect to the water heater outlet.
It doesn’t matter if it’s a tank type water heater, a tankless water heater, or a solar water heater, a good demand system will work with any of them.
What Is a Pex Manifold Plumbing System?
Pex is a modified polyethylene material that has good properties for use in water distribution systems. A PEX plumbing system uses PEX tubing including 3/8 inch, ½ inch and ¾ inch diameters.
Using PEX tubing allows you to use long continuous tubing runs between the source of hot water and the fixture without the need for elbows and other fittings. This keeps pressure drops to a minimum and reduces labor.
Typically PEX systems will have a main trunk line or lines connecting to manifolds. The manifolds normally have a shut off valve at each outlet so the individual piping runs can be turned off individually. 3/8 tubing is often used for the run from the manifold to the individual fixtures.
Advantages of PEX tubing
With such small diameter tubing the water velocity is high and so the hot water reaches the fixture more quickly than with a conventional piping system.
The low volume of water contained in the tubing results in a small conservation of water compared to conventional piping systems.
Other potential advantages include the ability to expand enough to absorb water hammer reducing the noise from suddenly turning off the water, and the ability to resist scale build up.
PEX tubing should not be exposed to sunlight and can’t be used where it will be subjected even to reflected sunlight.
Hot Water Pumps and PEX
Typical demand hot water pumps and systems would be beneficial for manifold type PEX systems in cases where the trunk line feeding the manifold was very long. In those plumbing layouts where the trunk lines are long, a demand pump can be connected between an outlet port on the hot manifold and an outlet on the cold manifold.
For “home run” type piping layouts, a demand hot water system would not be practical. You would need a pump for each run, and with the small tubing you would not be saving much water or time either.
Looped Plumbing with PEX
Looped plumbing, where the piping is looped from fixture to fixture when equipped with a demand hot water pump is the greenest solution. That way you can place a demand hot water pump at the end of the line, and get fast efficient hot water delivery at every sink. It will save a lot of water and it will be very energy efficient.
Tankless Water Heaters and PEX Plumbing Systems
There is no reason PEX tubing can’t be used with tankless water heaters. The hot water delivered by a tankless water heater is no different than the hot water delivered by any other kind of water heater.
In some cases PEX systems can benefit tankless water heaters since tankless heaters take a little longer to deliver hot water to the fixtures.
posted by Hot Water Guy at
11:03 PM
1 Comments:
Thanks for your post ... I try to use it in practice
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