Hot water recirculation

Assumptions: 

Assuming that an average household consists of 3 persons in average water waste a year is estimated to be 16.425 liters equals 66 bathtubs and 37 hours waiting a year 

  1. Number of times a person is waiting a day for water to get hot at a faucet is estimated to be 5 https://energysavingtrust.org.uk/sites/default/files/reports/AtHomewithWater(7).pdf  
  2. Number of liters wasted each time at a faucet is estimated to be 2 liters, with a faucet having a flow of 6 liters per minute https://ec.europa.eu/environment/ecolabel/documents/Sanitary%20Tapware%20Factsheet.pdf
  3. Number of times a person is waiting a day for water to get hot in a shower is estimated to be 1 https://energysavingtrust.org.uk/sites/default/files/reports/AtHomewithWater(7).pdf  
  4. Number of listers wasted in the shower each time is estimated to be 5 liters with a shower head having a flow of 15 liters per minute https://ec.europa.eu/environment/ecolabel/documents/Sanitary%20Tapware%20Factsheet.pdf
  5. According to the research organisation PRB the average number of people living in a household in Europe is 2,4. Rounded up this gives an average of 3 persons per household.
    https://www.prb.org/international/indicator/hh-size-av/map/country/
  6. Waiting time for hot water is estimated to be 20 seconds each time.  
  7. Length of the pipe from the water source/heater to the faucet and shower head is estimated to 20 meters 
  8. The bathtub size is estimated at 250 liters
    https://www.badeloftusa.com/ideas/how-much-does-bathtub-hold/

 

Sources: 

Energy Saving Trust (2013) "Water at home - The biggest ever review of domestic water use in Great Britain"
https://energysavingtrust.org.uk/sites/default/files/reports/AtHomewithWater(7).pdf (1, 3) 

Sustainability Info (2021) "How much Water does a Faucet Use
https://sustainabilityinfo.com/water/how-much-water-does-a-faucet-use/ (2, 4) 

PRB (2020) PRB’s World Population Data Sheet "Average household size" 
https://www.prb.org/international/indicator/hh-size-av/map/country/ (5)

Badeloft (2021) "How Many Gallons Does a Bathtub Hold?"
https://www.badeloftusa.com/ideas/how-much-does-bathtub-hold/ (8) 

 

Estimated savings:  

Replacing a UPS 6m, speed III with a new HWR pump from Grundfos 

Old UPS 6m - speed III - Watt use: 90W - Time running a day: 24 hours* - Watt use a day: 90W 

New COMFORT BASIC - Watt use: 7W - Time running a day: 24 hours* - Watt use a day: 7W - Savings: 92% 

New COMFORT DT - Watt use: 7W - Time running a day: 10,5 hours** - Watt use a day: 3W - Savings: 97% 

New COMFORT AUTOADAPT - Watt use: 7W - Time running a day: 2,5 hours - Watt use a day: 0,7W - Savings: 99% 

New ALPHA N 25-60 180  - speed II - Watt use: 28W - Time running a day: 24 hours* - Watt use a day: 28W - Savings: 69% 

New UPS N 20-60-180 - speed II - Watt use: 70W - Time running a day: 24 hours* - Watt use a day: 70W - Savings: 22% 

* With no external timer installed 

** COMFORT DIGITAL TIMER has a factory default setting where 21 enabled 30 minutes time slots are activated 

 

Supporting facts: 

Eco Friendly Habits (2021) "Water Waste Facts: Stats About Water Consumption & Usage"
https://www.ecofriendlyhabits.com/water-wasting-facts/  

Energy Efficiency Standards Group, Energy Analysis and Environmental Impacts Division (2011) "Water and Energy Wasted During Residential Shower Events: Findings from a Pilot Field Study of Hot Water Distribution Systems"
https://energyanalysis.lbl.gov/publications/water-and-energy-wasted-during

Energy Efficiency Standards Group, Energy Analysis and Environmental Impacts Division (2011) "Water and Energy Wasted During Residential Shower Events: Findings from a Pilot Field Study of Hot Water Distribution Systems"
https://eta-publications.lbl.gov/sites/default/files/water_and_energy_wasted_during_residential_shower_events_findings_from_a_pilot_field_study_of_hot_water_distribution_systems_lbnl-5115e.pdf  

Better Pressure Boosting Systems

Article page: LACK OF WATER PRESSURE OR NOISY BOOSTING SYSTEM

Decrease sound level 6 dB(A): Calculation from Patrick Glibert, Lead Sound & Vibration Engineer, Grundfos Sound Lab Denmark

Home Applicances sound level: https://www.nonoise.org/library/household/index.htm

Article page: COMPLICATED SELECTION, SIZING OR INSTALLATIONS

Assumption
4 hours of lost time is an estimation of extra time needed for the installer to solve issue from having to drive back and get the right components from the wholesaler, warehouse and finalise the installation.

Perfect water pressure

FACT: “ensure perfect water pressure in homes with up to 3 floors and 8 different taps”
Tap flow rates vary significantly depending on the type and geography. They can go anywhere between 5 and 15 l/min. Perfect water pressure is the constant 2 bar water pressure SCALA2 delivers at these taps.
By assuming an average tap flowrate of 7,5 l/min and the fact that SCALA2 can provide 2 bar/29PSI of pressure at 60 l/min, we conclude that SCALA2 can supply 8 taps at the time.
Therefore, the home can have even more than 8 taps, but SCALA2 can only supply 8 at the time with an expected comfort.

Note that higher flowrate taps would limit the number SCALA2 can supply.

Silent
FACT: […] “a noise level as low as 44 dB (A). This is a 3 dB(A) reduction in sound pressure compared to the previous generation, translating to a 50% perceived noise reduction to the human ear.”

Noise level: Measurement made in the Grundfos Sound and Vibration Lab and documented in a Sound Measurement Report according to ISO 3745.

“50% perceived noise reduction by the human ear”: Calculation made according to the theory in
Authors: Paul Peter Urone, Roger Hinrichs
Publisher/website: OpenStax
Book title: College Physics
Publication date: Jun 21, 2012
Location: Houston, Texas
Book URL: https://openstax.org/books/college-physics/pages/1-introduction-to-science-and-the-realm-of-physics-physical-quantities-and-units
Section URL https://openstax.org/books/college-physics/pages/17-introduction-to-the-physics-of-hearing

Energy efficiency

FACT: “By selecting the most efficient pressure boosters over traditional booster pumps, homeowners can enjoy significant savings, reducing their energy consumption for water boosting by as much as 40%.”

Calculation and assumptions for the reduction of energy consumption for water boosting by 40% if you replace traditional booster.

It is based on a comparison of CMB 3-46 and SCALA2 3-45. As CMB is what we consider a traditional booster, and we choose size 3-46 for 1:1 comparison with SCALA2 3-45. 
We assume that the pump is running 4 hours a day, 365 days a year. In the remaining 20 hours, the pump is not running.    
We assume that the demand is different over a day, so we use three different points (0.75m³/h, 1.5m³/h, 2.25m³/h).
We assume that during running hours, the pump will run 17% at duty point 1, 33% at duty point 2 and 50% at duty point 3.

We then read the power consumption at this flow demand at 30m head, to map the power consumption during the day.
This will result in the total energy used for the day. Multiply that with the total running days per year (365) and you get yearly energy use for both SCALA2 and comparison pump. Divide these two and convert to percentage then the savings equals 43%.

Calculation made in the Boosting Energy Calculation tool.

Better Heating Systems

Sources behind the stated facts: 

  1. Fact: Pumps are responsible for 10% of the total electricity in the world.
    Source: https://www.searchingindustrial.com/media/1078/pumps-could-change-the-world-again

  2. Fact: With a noise level at or below 29 dB(A), the sound emitted by ALPHA pumps, is quieter than a whisper at 30dB(A).
    Source: Sound power values L WA determined according to ISO 20361 1), ISO 3745 and ISO 4871.

  3. Fact: Research shows that 82% of heating systems in existing buildings in Germany alone in 2017, were incorrectly balanced.
    Source: CO2 online, 2017

  4. Fact: After this, your customers will have a system that not only provides better indoor comfort, but one that can offer between 5-20% energy savings annually.
    Source: Study of FH Münster, 2015

  5. Fact: Insufficient commissioning can cause up to 20% overconsumption of energy and poor comfort for your customers.
    Source: Study of FH Münster, 2015

  6. Fact: Roughly 82% of all heating systems are incorrectly commissioned.
    Source: CO2 online, 2017

  7. Fact: And they could reduce energy consumption by up to 20%.
    Source: Study of FH Münster, 2015

  8. Fact: Did you know that 200 million circulators worldwide are inefficient and 100 million in Europe alone?
    Source: This is calculated using a combination of Grundfos sales in both OEM and Trade, market share information and a model that estimates the average lifetime of the components within the circulators.

  9. Fact: Pumps that are over 10 years old are usually far less efficient than current models. In fact, replacing an old circulator can save up to 75% energy consumption.
    Source: Grundfos calculations based on product information: Old UPS (CC curve): 358,9 kWh/y - ALPHA2 AUTOADAPT 56,7 kWh/y

  10. Fact: Replacing an old circulator in a heating system can save energy, up to 75%!
    Source: Grundfos calculations based on product information: Old UPS (CC curve): 358,9 kWh/y - ALPHA2 AUTOADAPT 56,7 kWh/y

  11. Fact: For a typical family, that's about the same energy it takes to run the TV all year.
    Source: LCD TV running 3 hours a day - 230 kWh/y

  12. Fact: EU regulations are shaping the market for hydronic heating systems and we need to think differently when it comes to heating systems in order to reach EU's climate goal of cutting at least 40% of greenhouse gas emissions by 2020. 
    Source: https://climate.ec.europa.eu/eu-action/climate-strategies-targets/2030-climate-energy-framework_en 

  13. Fact: Reducing greenhouse gases by 40% by 2030: Just about everyone would rather their heating bill was lower, but more people today want their heating system to be more sustainable too. With that in mind, the EU has pledged to cut 40% of its greenhouse emissions by 2030.
    Source: https://climate.ec.europa.eu/eu-action/climate-strategies-targets/2030-climate-energy-framework_en 

  14. Fact: Your client will experience a comfortable, quiet home and may save up to 5-10% on their electricity consumption due to the new heat pump.
    Source: https://iea.blob.core.windows.net/assets/01324438-d634-4d49-95d8-3d08aaab00d5/TheFutureofHeatPumps.pdf

  15. Fact: Heat pumps can save 16% of total European Union energy use. 32% when looking at heating and cooling systems alone.
    Source: https://iea.blob.core.windows.net/assets/01324438-d634-4d49-95d8-3d08aaab00d5/TheFutureofHeatPumps.pdf 

  16. Fact: Traditional boilers typically operate with forward temperatures of up to 80 degrees Centigrade. To keep operation efficient, heat pumps should operate at the lowest possible flow temperature, preferably below 55 degrees centigrade.
    Source: https://iea.blob.core.windows.net/assets/01324438-d634-4d49-95d8-3d08aaab00d5/TheFutureofHeatPumps.pdf 

  17. Fact: When the heat pump is installed and commissioned correctly, the conversion from renewable energy to useful heat becomes very efficient, and the householder will experience a comfortable, quiet home and may save up to 10% on the electricity consumption of the heat pump.
    Source: https://iea.blob.core.windows.net/assets/01324438-d634-4d49-95d8-3d08aaab00d5/TheFutureofHeatPumps.pdf 

  18. Fact: Old functioning pumps use up to 17 times the energy of a new Grundfos pump
    Source: Grundfos calculations based on product information: Old UPS (CC curve): 83.5 kWh/y - ALPHA2 AUTOADAPT 4.6 kWh/y

  19. Fact: But there’s an easy way you can go from consuming 84 watts to a mere 5 watts, just by replacing your heating pump
    Source: Grundfos calculations based on product information: Old UPS (CC curve): 83.5 kWh/y - ALPHA2 AUTOADAPT 4.6 kWh/y