Sometimes it is the apparently simple devices that have the biggest impact on our lives. The humble toilet is calculated to have saved 1 billion lives since its invention due to the positive impact it had on the cleanliness of our cities (which used to be pretty abysmal). 1 billion lives saved is about the same number of lives saved via the much more complex development of synthetic fertilizers through the Haber-Bosch process, which staved off famine all over the world.
While perhaps not in the same life saving category as the aforementioned innovations, the ultra low flow (ULF) shower head has the potential to save an enormous quantity of water and energy with widespread use.
So how do you back-up your claim that ULF shower heads can save so much energy and water you might ask?
Well let's assume there are 20 million people who take a shower daily in Australia (excluding people who take baths). The average shower length is around 7.5 minutes and the average shower head uses somewhere around 12.5 L/minute, assuming a mix of 'water-saving' and non-water saving shower heads.
ULF showerheads like the Methven Kiri Satinjet have a stated flow of 5L/min, which means if you replaced the average Australian shower head with ULF shower heads across Australia you would save 0.75 billion liters of water a day or 273 billion liters of water per year. This is an impressive amount of water when you consider 273 billion liters of water is about 8 month's supply of water to the entire city of Melbourne.
But water is only half the picture here because showers use hot water and hot water requires energy. How much energy? Well to heat 273 billion liters of water from 18 C° (temperature from your cold tap) to 40 C° (average shower water temperature) requires about 7 billion kWh or about 10 billion kWh (assuming 70% water heater efficiency). 10 billion kWh is enough to power 1.7 million average Australian households for a year.
Pretty impressive numbers for a humble shower head, so no wonder it pays itself back in saved water and energy costs in less than 12 months (depending on use of course).
It is also important to point out that modern ULF shower heads like the Methven Kiri Satinjet feel like they have higher water flows due their Satinjet technology which produces many more water droplets than a conventional shower per liter of water used. The upshot being more of the warm water contacts your skin than a regular shower giving you the feeling you are using more hot water than you actually are.
Less water and energy used and a better shower experience, what is not to like!