Case Study: Efficient Showerhead
by Rod Dempsey
Using an efficient showerhead is an easy and effective way to reduce water consumption and carbon dioxide emissions and save money.
There are three reasons why it is important to use an efficient showerhead. 1. According to Environment Canada, more water is used in households for showers and baths than for any other use. Our growing demand for water is placing increasing stress on the environment and our water supply and sewage treatment infrastructure.
2. that energy is required to increase its temperature from approximately 10o C (50o F) when it enters your house to 37o C (99o F) when it leaves your showerhead. 3. If the water is heated using any method other than a solar domestic hot water system, then fossil fuels or biomass are being consumed and carbon dioxide and pollutants are being released into the atmosphere for every litre of water used.
The term “low-flow” defines a showerhead that delivers no more than
Hot water is expensive water in 9.46 litres (2.5 U.S. gallons) of water per minute at 80 p.s.i. of water pressure. While this is an improvement over showerheads with higher flow rates, it still leaves considerable room to reduce flow rates while maintaining an acceptable level of showerhead performance. The purpose of this case study is to provide data and savings relating to the use of an
efficient showerhead as compared to a hypothetical 9.46 litre per minute showerhead.
The featured showerhead is available from the Home Depot (“The Incredible Head Power Showerhead,” Product No. 157624, Alsons ES141 showerhead), Home Hardware (SKU No. 3266913) and from Canadian Tire (“Plumb Shop Fixed Chrome Showerhead” No. 63-0157-8).
A series of ten measurements determined that the average flow
rate of the showerhead was 3.76 litres per minute. The two adults and two children in the household cumulatively take about three showers each day for a total of 21 showers per week and 1,092 showers per year. With an average duration of 7 minutes per shower, the showerhead is in use for 127 hours and 24 minutes per year.
Compared to a showerhead with a flow rate of 9.46 litres per minute, the efficient showerhead will save the following amounts annually: 43,571 litres of hot water, 161 litres of oil, $129, and 435 kilograms of carbon dioxide per year (which is equivalent to taking a 2010 Honda Civic Hybrid off the road for two and a half months). As such, the showerhead has a simple payback of less than 0.1 years and has provided a tax-free return on investment of 860 percent since its installation in the household in 2007.
So, should you rush out to buy your own efficient showerhead? Not without first determining the flow rate of your existing shower-head. This is easily accomplished by holding a bucket under the showerhead for one minute and then using a kitchen measuring cup or container to measure the volume of water in the bucket in litres. If the flow rate is greater than 5 litres per minute, then consider making that trip to the hardware store. (Based on taking showers of 7 minutes duration, even a 1 litre per minute reduction in flow rate will save 2,555 litres of hot water per person per year.)