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CASE STUDY

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Helen Mubarak
Grundfos North America
913.302.3702
hmubarak@grundfos.com

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john.oreilly@oreilly-depalma.com

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News/Press Release

Grundfos Pumps Unveils New Generation of Circulators, With Power‐Consumption Savings of up to 80% or more


PROJECT PROFILE

Location:
Webster, Wisconsin

Venue:
Residence

System Type:
Circulator Pumps


PROJECT DATA

Structure Type:
Single-family dwelling

Area Heated:
5,000 square feet

Tubing Layout:
1) Uponor hePEX™ buried in basement slab

2) Insulated PEX stapled below second and third floors

Outdoor Design Temperature: -25°F

Heat Plant, Size:
Empyre 250 wood-fired boiler (150,000 BTU)

System Supply Water Temperature: 120°F

Tubing Size:
1" main supply; 5/8" zones — all from Uponor

Number of Loops,
Average Length
:
25 loops, 300 feet

Tubing Spacing:
12" on center

 

Grundfos ALPHA Circulator Saves Energy

New Generation of Circulator Pumps Spurs Dramatic Energy Savings for Off-Grid, Solar Home

Homeowner Michael Sperry replaced a conventional circulator in his radiant heating system with a new Grundfos ALPHA™, cutting power consumption from 186 watts to 19 watts with no sacrifice in comfort. After all, “we are accustomed to keeping our thermostat at 76°F during the coldest months,” he explains.

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— Comfort was the only demand that Michael Sperry’s wife Judy made when he proposed building an off-grid, solar-powered home in northwest Wisconsin. “She was willing to go along with my environmental experiment as long as our family wouldn’t be uncomfortable,” recalls the automotive body-repair shop owner, who selected radiant floor heating to satisfy his wife’s concerns.

Indeed, at just over 5,000 square feet, the four-bedroom, three-story home does not sacrifice creature comfort; nor, for that matter, electricity. Because the home generates all its electricity from solar power, everything – from mechanical systems to appliances – optimizes energy use.

In addition to fueling the home’s radiant heating system and domestic hot water, the solar photovoltaic panels provide power for all the modern appliances and amenities you would expect in a 21st century American household: washer, dryer, dishwasher, personal computer and even a 42-inch plasma television.

In fact, one of the major challenges for the project was to power the home’s heating system while using less energy than a 200-watt light bulb. The system today exceeds this seemingly implausible goal, drawing just one-tenth of that 200-watt target – 19 watts – thanks to a revolutionary new circulator from Grundfos Pumps.

Sperry ResidenceFirst introduced by Grundfos in Europe earlier this decade, the ALPHA™ is an energy-optimized, 115-volt circulator that features a permanent magnet motor designed to cut power consumption by at least 50% and usually more, as compared with other circulators in its class. For Sperry, the savings went well beyond 50%.

Emphasis on energy savings: “In designing a radiant heating system for a luxury home such as this, we would normally spec 10 pumps: a primary pump, a secondary loop pump, an injection/mixing pump plus seven zone pumps,” explains heating contractor and system installer Terry Burns. “In an off-grid home, this was totally unacceptable, as it would have required roughly 900 watts of power per hour.”

To scale back the energy usage, Burns drew upon technology normally used in commercial-industrial applications. He replaced the seven zone pumps with pressure differential valves (which require no electricity) and eliminated the injection/mixing pump, as well as the secondary loop pump.

As a result, the one and only remaining pump in the system design was a single circulator to bring hot water from Sperry’s outdoor wood-burning boiler to the main manifold, where it travels throughout the home’s 9,000 feet of Uponor PEX (crosslinked polyethylene) tubing buried in the basement slab, as well as stapled under each of the two upper floors.

But while the single-pump design performed as expected, its energy use exceeded plan and placed a significant drain on the home’s electric power, which limited use of other appliances and devices.

“The original circulator did the job, but was an energy hog,” Sperry remarks. “We have a spreadsheet showing what all of our appliances and electrical components draw throughout a normal day, and we monitor it very closely. The original pump was drawing 186 watts continuously, and depleting our solar battery bank by roughly 15% overnight.”

System designer Burns spent months searching for an alternative, but “could not find anything that fit our parameters in terms of pump head and flow rate,” Sperry explains. “There simply was nothing suitable for this application that would reduce energy use.”

Breakthrough technology: In March 2008, Burns learned about the breakthrough Grundfos ALPHA and immediately realized that this high performance, low-energy-use circulator was his answer. “Although the ALPHA pump wasn’t yet commercially available, I knew this was the only thing out there that could solve our energy issue,” recalls Burns, who was able to get a unit to test in the Sperry home.

“The pump exceeded the manufacturer’s claims – and my wildest dreams – in every category,” says Burns, “energy use, performance [homeowner comfort] and its silent operation.”

Intended for residential and light-commercial hydronic applications, ALPHA features the innovative AUTOADAPT™ function that automatically and continuously adjusts circulator performance to the changing needs of the heating system. The circulator will automatically find the lowest possible operating-efficiency point to meet demand, notes Burns, thereby saving both energy and money.

This winter of 2008-2009 — one of the coldest on record in the Upper Midwest — delivered a quick and dramatic payoff on Sperry’s new investment. The ALPHA cut electrical consumption by 90% almost immediately, without any sacrifice in personal comfort, according to Sperry, who notes: “We are accustomed to keeping our thermostat at 76°F during the coldest months.”

Meanwhile, the backup gas generator that ran for 205 hours during the winter of 2007-2008 was needed for only 86 hours this past winter, despite the colder temperatures because there was enough battery power left to keep the radiant system running. This reduced gas usage resulted in a 70% decrease in the gas bill from one winter to the next, reports Sperry, from $565 to $170. Moving forward, Sperry estimates he’ll use his generator for just 50 hours, as he becomes more familiar with the system’s operation.

“We couldn’t be happier with the ALPHA’s performance. We’ve had no problems at all, and the pump is virtually silent, which is heaven compared with the obnoxious hum that reverberated throughout the house from the previous pump.

“I talk with a lot of off-grid people about the heating systems we all use,” Sperry continues, “and they warned me that my biggest headache would be the water-circulating pump, because it typically uses so much energy. But the ALPHA has proven to be an absolute dream. For any homeowner who wants to move off-grid or simply to maximize energy efficiency, this is the best way to go.”

ABOUT GRUNDFOS
With an annual production of more than 17 million units, Grundfos is the world’s leading pump manufacturer, serving the residential, commercial-building and process-industry markets, as well as being a major supplier to the ground water, irrigation, water-supply and water-treatment industries. The company specializes in circulator pumps for heating and air conditioning as well as other centrifugal pumps for industrial applications, water supply, sewage and dosing. In addition to pumps, Grundfos also produces standard and submersible motors as well as state-of-the-art electronics for monitoring and controlling pumps.

Founded in 1945 in Bjerringbro, Denmark, The Grundfos Group employs nearly 20,000 in 82 countries on five continents worldwide, including 1,400 in the United States. A top priority on the Grundfos corporate agenda is an active commitment to improving the environment, both in terms of providing innovative pumping solutions as well as reducing the company’s own footprint. The company contributes to global sustainability by investing heavily in research and development to pioneer technologies that improve quality of life for people and care for the planet.

For more information, visit the website at www.grundfos.us or view the Grundfos Corporate Sustainability Report at http://www.grundfos.com/about-us/reports/sustainability-reports.html. You can also follow us on Twitter and Facebook.

For editorial assistance, contact: 1) John O’Reilly or Joel Williams, c/o O’Reilly/DePalma, 32 West Nebraska Street, Suite 1C, Frankfort, Illinois 60423; tel.: 815-469-9100, extension 302; fax: 815-469-2555; E-mail: john.oreilly@oreilly-depalma.com or joel.williams@oreilly-depalma.com. 2) Helen Mubarak, Communications Officer, Grundfos. Tel. 913-302-3702; E-mail: hmubarak@grundfos.com.

# # #

 

Facts and Figures:

  • According to USA Today as of 2006, there were 180,000 families living off-grid, a figure that has jumped 33% a year for a decade.

  • Heating and cooling account for almost 50% of the typical American home’s annual energy consumption.

  • While radiant floor heating systems tend to yield consistent room temperatures, buildings heated with forced air can vary by more than 15°F between a room’s floor and ceiling temperature.

  • Solar homes leverage the large mass of concrete or rock, which work to absorb, store and re-radiate heat evenly and efficiently right at floor level, making the homeowner feel more comfortable.


Project Data:

  • Structure Type: Single-family dwelling

  • Area Heated: 5,000 square feet

  • Tubing Layout: 1) PEX buried in basement slab; 2) insulated PEX stapled below second and third floors.

  • Outdoor Design Temperature: -25°F

  • Heat Plant, Size: Empyre 250 wood-fired boiler (150,000 BTU)

  • System Supply Water Temperature: 120°F

  • Tubing Size: 1" main supply; 5/8" zones — all from Uponor

  • Number of Loops, Average Length: 25 loops, 300 feet

  • Tubing Spacing:12" on center



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IMAGE GALLERY: Grundfos ALPHA Circulator Saves Energy


To download a hi-res .tif file,
click on the desired image and a zip archive automatically downloads to your computer. Due to how various browers handle downloads, you may have to expand the zip archive manually.

The zip archive expands into a .tif file (300ppi; 6" x 4"; CMYK; unless otherwise specified).


 

By immediately cutting electrical consumption 90%, Michael Sperry’s new Grundfos ALPHA circulator (above) has proven to be an “absolute dream” for his off-grid, solar-powered residence.

File Name: sperry-family-16.tif
Image Size: 4" wide x 6" high (1200 x 1800 pixels)


 

The Sperry Residence is a three-story, 5,000 square foot off-grid, solar-powered home in northwest Wisconsin. Because the home generates all its electricity from solar power, everything – from mechanical systems to appliances – optimizes energy use.

File Name: sperry-family-12.tif
Image Size: 6" wide x 4" high (1800 x 1200 pixels)


 

Contractor Terry Burns, now retired, installed the radiant heating system in Sperry’s home, including the ALPHA circulator. “The pump exceeded the manufacturer’s claims – and my wildest dreams in every category — energy use, performance and its silent operation.”

File Name: Terry-Burns3.tif
Image Size: 6" wide x 4" high (1800 x 1200 pixels)


 

Michael and Judy Sperry with their two children: Sperry’s wife was “willing to go along with my environmental experiment as long as our family wouldn’t be uncomfortable,” he says. Sperry chose to install radiant heating to satisfy Judy’s concerns.

File Name: sperry-family-8.tif
Image Size: 4" wide x 6" high (1200 x 1800 pixels)


 

Michael and Judy Sperry with their two children: Sperry’s wife was “willing to go along with my environmental experiment as long as our family wouldn’t be uncomfortable,” he says. Sperry chose to install radiant heating to satisfy Judy’s concerns.

File Name: sperry-family-10.tif
Image Size: 6" wide x 4" high (1800 x 1200 pixels)


 

The heat source for the Sperry home’s radiant heating system is a wood-burning boiler located outside the home and next to a propane-fired boiler used for backup.

File Name: sperry-family-2.tif
Image Size: 6" wide x 4" high (1800 x 1200 pixels)


 

The heat source for the Sperry home’s radiant heating system is a wood-burning boiler located outside the home and next to a propane-fired boiler used for backup.

File Name: sperry-family-4.tif
Image Size: 4" wide x 6" high (1200 x 1800 pixels)


 

The Grundfos ALPHA circulator installed in the Sperry home. The system’s original circulator, according to Sperry, “was drawing 186 watts continuously, and depleting our solar battery bank by roughly 15% overnight.” The ALPHA draws only 19 watts, with no sacrifice in comfort.

File Name: sperry-family-21.tif
Image Size: 4" wide x 6" high (1200 x 1800 pixels)

 

 

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