Softeners help preserve the efficiency of water heaters and major appliances and keep showers and faucets unclogged, the report found.
The study was commissioned by the Water Quality Research Foundation (WQRF) in 2009.
Battelle Memorial Institute is a renowned independent testing and research facility dedicated to applied science and technology development.
Among some of the key findings of the study:
Indoor instantaneous gas water heaters (tankless heaters) operated on softened water maintained the original factory efficiency rating over a 15-year lifetime. The study found that tankless water heaters completely failed to function because of scale plugging in the downstream plumbing after only 1.6 years of equivalent hot water use on 26 gpg hard water. Softened water saves 34% of costs compared to operating on 20 gpg and saves 47% compared to operation on 30 gpg hard water.
Gas water heaters:
Gas storage tank household water heaters operated on softened water maintained the original factory efficiency rating over a 15-year lifetime.
On the other hand, hard water can lead to as much as a 48% loss of efficiency in water heaters.
Each five grains per gallon of water hardness causes a 4% loss in efficiency and 4% increase in cost for gas storage tank water heaters when using 50 gallons of hot water per day.
(On 30 gpg hard water, that’s 24% less efficient than with softened water.)
Each five grains per gallon of hardness causes an 8% loss in efficiency and 8% increase in cost when using 100 gallons of hot water per day in a gas storage tank water heater.
(On 30 gpg hard water, that’s 48% less efficient than with softened water.)
Electric water heaters:
Up to 30 pounds of calcium carbonate rock-like scale can accumulate in these heaters over time, according to the study. The life of the heating element will be shortened due to scale buildup because of increased operating temperature of the heating element. Also each five gpg of water hardness causes 0.4 pounds of scale accumulation each year in electric storage tank household water heaters. Such scale adversely affects the water heater’s performance. Battelle says in the electric storage water heaters operating on unsoftened water “the life of the heating element can be expected to shorten due to scale buildup increasing the operating temperature of the element.”