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This article discusses On-Demand Hot Water Recirculating Systems That Provide Instant Hot Water.  Al’s Plumbing, Heating & A/C, in Plano, Texas provides full-service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s Plumbing, Heating & A/C is near your home in Plano, TX; Allen, TX and Frisco, Texas.  We service all homes in southern Collin County, TX and Denton County, TX with no additional travel charge.

Al’s also provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally, we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard), and Coleman HVAC (same company as York HVAC).   Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience.

How Long Does Your Faucet Run Before The Water Gets Hot?

Each year, a family of 5 wastes approximately 15,000 gallons while waiting for hot water — and paying for both the water and the sewage fee. **

** Source:http://aquamotionhvac.com/hot-recirculation-systems/

bathtub filling with water

Image Source: ShutterStock

We’ve all experienced it.  You turn on the hot water faucet — and wait until the hot water arrives.   You’ve wasted water, and the energy the water heater used to heat water pipes between it and the faucet.

Wanting A Hot Bath?  You’ll have to make it quick.  Because if you want more hot water later — you’ll have to run a lot of cool water into the tub first.

 

Water Heater Sludge Build Up Often Slows Hot Water Delivery Speed

Click Here To Spot The Signs Your Water Heater Is About To Fail:  10 Signs Your Water Heater Is About To Fail

 

How Long You’ll Wait For Hot Water Partially Depends On Your Hmes Water Pipes

Most new homes built since the mid 1980’s have PEX Water Supply Lines.   PEX is Cross-Linked Polyethelene — A Flexible Polymer Invented In The 1930’s. 

Benefits To The Home Builder:

  • The PEX material is less expensive that copper.
  • Installation time is dramatically reduced.  This is because PEX has fewer joints PLUS PEX can be attached to a joint-fitting with a crimp-ring.  With copper water pipes — each connection must be soldered.

copper water pipes main line and branch line

Image Source: ShutterStock

Shown: A Copper Water Pipe Being Soldered At A Joint.

Benefits Of PEX For The Homeowner:

  • Because PEX is more freeze-resistant.  It can be installed underground or in the attic in homes in the southern U.S.   When PEX is  in the attic, access to the pipes is much easier than digging under the home
  • PEX is flexible and bends around many turns.  This reduces the number of joints (see gold-colored metal joints in the photo  below).  Where water changes direction — turbulence occurs.
  • Fewer Joints Creates:
  • Less water turbulence — due to far fewer fittings than copper.
  • Less noise from the water pipes — water makes more noise at locations where it changes direction.
  • Higher water pressure at the faucets.
  • Copper is subject to corrosion — both inside and outside the pipe.  PEX doesn’t corrode (but corrosion might occur at the metal joints).  Polymer joints are increasingly being used with PEX — if these fittings are used — they are corrosion-resistant.
  • In DFW, PEX is less likely to cause a slab-leak —  because PEX’s flexibility accommodates slab movement (that occurs due to changing moisture levels in the soil under the home).

PEX water lines with copper connections

Image Source: ShutterStock

Shown Above: PEX Flexible Water Lines With Brass Connections

Source: https://www.finehomebuilding.com/2009/03/02/three-designs-for-pex-plumbing-systems

How PEX Reduces The Wait For How Water:

  • PEX retains heat better than copper water pipes.
  • PEX also has less pipe between the water heater and the faucets (details just below) — Because PEX use a Manifold System —  and each fixture has its own water supply line.
  • This reduces the amount of water pipe between the water heater and the faucet.

pex water lines manifold

Image Source: ShutterStock

Shown: Pex Water Supply Lines Manifold

 

Heat Loss Of Copper Water Pipe Versus PEX Flexible Water Lines

The faster the home’s water pipes lose heat — the more expensive a 24/7 Hot Water Recirculating System becomes.  Heat escapes from copper water pipes 850 times faster than PEX flexible water lines.  ***

Heat Loss:

  • Copper = 2,720
  • PEX = 3.2.
  • Copper pipe loses heat 850 times faster than PEX (3.2 x 850 = 2,720)

*** Source: https://insulationinstitute.org/wp-content/uploads/2015/11/CI226.pdf

 

COPPER water pipes:

  • A large (usually 3/4″) main water pipe. Using a tree analogy — this pipe is often called: “trunk line.”
  • Along with the trunk-line — smaller branch-lines (3/8″ — 1/2″) head toward each fixture.  Each fixture has its own branch lines.
  • Before the fixture receives hot water — the trunk line must be filled first.
  • Once the hot water in the trunk pipe reaches the branch-lines that serve the fixture — hot water heads toward the fixture and its fauect.

 

copper water pipes main line and branch line

Image Source: ShutterStock

Shown: A Copper Water Trunk Line — Where A Branch Line Heads Toward A Fixture

 

There Are Solutions To Waiting A Long Time For Hot Water.

And Some Are More Energy-Efficient Than Others.  

 

1. (Constant) Hot-Water Recirculating Pump

(Saves Water — But Is Not Energy Efficient Because It Keeps Water Pipes Hot 24/7)

hot water recirculating pump

Image Source: ShutterStock

SHOWN: The Hot Water Recirculating Pump Is Red.  It’s Located Near The Center Of The Photo.

 

With a 24/7  Hot Water Recirculating System – hot water is running through the lines all the time. **   You don’t waste water — but this convenience comes with the cost of keeping the hot water lines throughout the entire home heated all the time.    The pump moves heated water into the hot water lines (throughout the home) and returns the cold water to the water heater.   This causes the water heater to run more — and it’s even more expensive if you have an electric water heater.

** NOTE:  There are systems with timers to eliminate recirculating during times when little or no hot water is needed.

 

There’s an additional, hidden cost.  Constant recirculating hot water systems add heat (escaping the water pipes) into the home.

  • While water pipes adding heat may not seem to be a problem in winter — water heaters are about 60% efficient.  The other 40% of the heat goes up the flue with the exhaust-gases.   As compared, today’s gas furnaces are as high as 98% efficient.
  • The water heater runs 3-4 times more frequently.  **
  • Plus, DFW is in a “Cooling Climate” — this means we cool our homes more than we heat them.   During DFW summer, heat escaping from hot water pipes puts additional demand on the A/C.

 

**Souce: https://ecoperformancebuilders.com/smart-hot-water-recirculation-systems-huge-energy-savings/

Source: https://www.greenbuilt.org/finally-a-decent-alternative-to-hot-water-recirculating-loops/

 

2. On-Demand Hot Water Recirculating Systems

(Saves Water — And Is Notably More Energy Efficient — Because It Only Runs When You Want It to)

Click On The White Arrow (in the center of the image above) To See An Diagram Of How An On-Demand Hot Water Recirculating System Works

 

With an On-Demand Hot Water Recirculating System, you get:

  • The water savings of a 24/7 Recirculating System. 
  • The energy-efficiency created by running the recirculating system running only when needed.
  • Note: With copper water pipes — minerals in the water (or how “hard” the water is) can wear the inner lining of water pipes — especially where water changes direction (like fittings & elbows). **
  • In areas with hard water — a hot water recirculating system might enhance this problem.
  • The water hardness in DFW is 8 grains per gallon. ***
  • 7-10 grains per gallon is considered “hard” water.  ****

So, the less time a hot water recirculating system runs (in areas with hard water) — the less wear on copper pipes.

** Source: https://redcapplumbing.com/help-guides/troubleshooting/how-to-prevent-pinhole-leaks-in-copper-pipes

*** Source: https://www.hydroflow-usa.com/texas-water-hardness

**** Source: https://www.h2odistributors.com/pages/info/hard-water-map.asp

 

There Are Many Brands & Models Of On-Demand Hot Water Recirculating Systems — And They All Work Much The Same. 

A common On-Demand System includes a small pump under the sink.    The ON button is typically located within reach of the fixture.   When someone wants hot water, they press the button.  The pump moves (cool) water from the hot water line, and returns that water to the water heater through the cold water line.   Once the water temperature at the faucet is hot, the pump turns off.

A. Click Here To See A Hot Water Recirculating System Diagram: Hot Water Recirculating System Diagram

B. Click Here To See An On-Demand System Water Pump Installed Inside A Bath Vanity: On-Demand Hot Water System Pump Installed

C. Click Here To See A (uninstalled) Button For Use With An On-Demand Hot Water Recirculating System: On-Demand Hot Water System Button (uninstalled)

An On-Demand Hot Water System Works Differently Depending On The Type Of Water Pipes In The Home

 PEX Flexible Water Lines With A Manifold System

With a PEX Manifold Water Pipes System — every fixture has its own water line.  On-Demand pumps can be on selected fixtures, or at every fixture.  When hot water is demanded, the pump fills only the water line serving that fixture.

hot water recirculating pump

Image Source: ShutterStock

SHOWN: Manifold Water Pieps Systems.

PEX water pipe

Image Source: ShutterStock

SHOWN: PEX Flexible Water Lines Are Installed In Most Newly-Built Homes.

In Existing Homes:  PEX is Often Installed (in the attic) — Instead Of Replacing Leaking Copper Water Lines (under the slab).

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This article discussed On-Demand Hot Water Recirculating Systems That Provide Instant Hot Water.  Al’s Plumbing, Heating & A/C, in Plano, Texas provides full-service plumbing maintenance, repairs and replacements for every plumbing component in your home.  Al’s sells and installs Rheem Professional Series gas & electric water heaters, and tankless water heaters.  Al’s Plumbing, Heating & A/C is near your home in Richardson, TX; Garland, TX and Wylie, Texas.  We service all homes in southern Collin County, TX and Denton County, TX with no additional travel charge.

Al’s also provides maintenance & repairs for all brands of Central A/C, Gas & Electric Furnace, and Heat Pumps.  Additionally, we sell and install new HVAC Systems from American Standard (same company as Trane), Ameristar (same company as American Standard), and Coleman HVAC (same company as York HVAC).   Call Al’s today to discuss any concerns or problems you have with your HVAC System or Plumbing.  We will arrange an appointment at your convenience.