Saving Water and Money

ダHow much does
Dynastream save water?


How much does Dynastream save water compared to a conventional shower head?
We compared the amount of discharged water by connecting each of the two shower heads to a pump which is not affected by the pressure from waterworks.

  • Conventional head   16.8 L/minute
  • Dynastream   9.6 L/minute

The result showed
that Dynastream saves approximately 40 % of water.

Without a shower head, the pump discharges 20L of water per minute.

How much does
Dynastream save money?


Saving water can lead to cut down of

  • Water bill:  - about 10,800 yen/ year
  • Gas bill:  - about 6,444 yen/ year

You can save about 17,000 yen!

Our estimation

Saving Water Bill

  • ・The time of taking a shower is 4 minutes per bath, and there are 4 people in the household.
  • ・The shower is used 40 times during 2 months.
  • ・The nominal diameter of the shower is 20mm.
  • ・Water discharge amount of shower heads:
    <Conventional head> 16.8 L/minute
    <Dynastream> 9.6 L/minute (40% reduction)
  • ・Water used by a shower (during 2 months)

    <Conventional head> 16.8 L/min x 4 mins. x 4 people x 40 times =10,752 L
    <Dynastream> 9.6 L/min x 4 mins. x 4 people x 40 times = 6,144 L

The amount of water saving = 10,752 L – 6,144 L = 4,608 L (4.608 m³)/ 2 months

Water charge that can be reduced
  • Kyoto City:
    1,840 yen (Basic fee) + 10 yen (for sewer) = 1,850 yen/2months
    ※According to the charge table on the website of Kyoto Waterworks Bureau.
  • Tokyo 23 Wards:
    1,263 yen (Basic fee) + 604 yen (for sewer) = 1,867 yen/ 2months
    ※According to the charge table on the website of TMG Bureau of Waterworks.

Approx. 1,800 yen÷2 (= Charge for 1 month) x 12 months = 10,800 yen 
You can save approx. 10,800 yen per year.

Saving Gas Bill

  • ・The temperature of water is increased to 40 degrees Celsius (for bath) from 20 degrees Celsius (for normal use).
  • ・The amount of heat needed for raising one degree Celsius for 1 m³ of volume is estimated to 11,000Kcal.
  • ・The amount of water saving in 2 months: 4,608 L (4.608 m³)/ 2 months
  • 4.608 m³ x 10³ kcal x (40 degrees Celsius – 20 degrees Celsius)11,000 kcal/m³ = approx. 8.4 m³ (fuel consumption) / 2 months
  • ・8.4m³ x 128 yen (Reference: Tokyo Gas 2014 Table B) = Approx. 1,075 yen/ 2 months

1,075 yen ÷ 2 (= 1 month) x 12 months: = 6,444 yen 
You can save approx.6,444 yen per year.

Total Saved Charge

10,800 yen (water bill) + 6,444 yen (gas bill) = 17,244 yen/ year
You can save about 17,000 yen per year!

  • Eleven households had participated in the global warming countermeasure project of Kyoto City, “DO YOU KYOTO?” for a year since October 2014. Using the water-saving shower head, “Dynastream,” they have contributed to reduction of CO2 emissions by cutting gas consumption.
  • They replaced their shower heads to Dynastream, and tested the energy-saving effect by measuring gas consumption for twelve months.
  • The number of people in the participant households varied from two to six. The total 12-month gas consumption of all households in 2013 was 4,570 m³, meanwhile, the consumption of the same months in 2014 was totally 3,991 m³. Compared to 2013, 579 m³ of gas were saved in 2014. When it’s converted to the reduction amount of CO2 emissions, it is approx. 4,322 kg (according to the value presented by Kyoto City Environment Policy Division, Global Warming Countermeasure Section).
  • The largest reduction amount of gas charge was 95,000 yen/ year, which was achieved by the household of six members.
  • The gas meter slips of the twelve households proved that the gas consumption can be surely reduced only by replacing a shower head to Dynastream.