Hot%20Water%20Recirculation%20Pumps. - PowerPoint PPT Presentation
Title: Hot%20Water%20Recirculation%20Pumps.
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Hot Water Recirculation Pumps.
- Tim Pehl
- Outside Sales Rep For Dawson Company.
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Topics
- Scenario.
- How a recirculation Pump works.
- History of recirculation Pumps.
- Latest technology.
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Scenario.
- We get up in the morning and we turn on the
- hot water to take a shower.
- we put our hand into the stream of water to
- check the temperature, and it is cold.
- We may wait for a full 60 seconds, or longer,
- before we can step in and take our
- shower.
- Why??
- We dont have a recirculation pump!
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Scenario.Dead end piping
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Scenario.
- Residence is three bedroom with four occupants
and two baths. - Water heater is approximately 60 from master
bedroom - Hot water supply line from water heater is
un-insulated ¾ copper pipe - Assume the following volume of hot water wasted
per day - Master lavatory 1.5 gal fixture 2.625 gal
wasted/day - Second bathroom lavatory 1.5 gal fixture 7.5 gal
wasted/day - Master Shower 2.5 gal fixture 15 gal wasted/day
- Second bathroom shower 2.5 gal fixture 2.625 gal
wasted/day - Kitchen Sink 2.5 gal fixture 12.5 gal
wasted/day - Water consumption is based on the system
operating 350 days per year - Total water wasted in a year is 14,087 gallons
based on total water wasted of 40.25 gallons per
day
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Scenario.
- How Much Water is 14,000 Gallons?
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Scenario.Return line added with Circulator.
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How a pump works
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SYSTEM CURVE
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Recirculation pump with ECM technology
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Standard Induction Motors
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ECM ( Electrically Commutated Motor) Technology
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Induction Vs Permanent Magnet
- Permanent Magnet Motor
- Permanent magnet on rotor
- Eliminates the requirement for input power to
magnetize rotor - Stator coils generate a rotating field to induce
the permanent magnet to rotate - Motor is microprocessor controlled to keep the
stator current in phase with the magnets of the
rotor. - The lower current requirement and no slip
result in greater efficiency.
- Induction Motor
- No magnet on rotor
- Stator coils create magnetic field which induces
current into rotor - The rotor currents interact with the rotating
magnetic field which causes a rotational motion
on the rotor. - Because the magnetic and electric fields are out
of phase (slip), there are greater current
requirements and current losses.
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Comparison Spherical Motor vs. Canned Motor
- Key Advantages
- Simplicity just one high precision part
- No shaft, no bearing bushings
- Self-aligning rotor
- Long term quiet and trouble free operation
- No start-up problems
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SYSTEM CURVE
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System Curve
System Curve
System Curve
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Recirculation pump with ECM technology
Variable speed option can reduce smallest pump
energy consumption even further..
e3-4
System Curve
System Curve
Flow (GPM)
Duty Point 5 Watts
Duty Point 40 Watts
88 LESS ENERGY CONSUMPTION
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One Switch - Two Options
- Every ECM circulator has a switch installed- you
have the choice - Variable Speed Control
- Variable Temperature Control(68 to 158 Deg.F.)
Variable Temperature Control
Variable Speed Control
NEED PIC
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Options
- Most pumps come standard with constant speed.
- Power cords are sometimes optional.
- Variable speed.
- Temperature control.
- Time clocks
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What if I dont have a return line?Autocirc 14
watts
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But I have a Tankless water heater
- Sizing a pump for Tankless water heaters is the
same as a tank type. However, a larger pump will
be needed as the Tankless units have a heat
exchanger inside that produces a higher pressure
drop.
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Questions?
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