Sustainability in Clothes Washing

by Richard M. Goodman

A previous blog post addressed the relative hazards or toxicity of cleaning chemicals, emphasizing that minimal human toxicity and environmental impacts promote sustainability.  In addition to detergent selection, another aspect of the simple household chore of clothes washing is the energy utilized.  Depending on the size of your family and how frequently you wash clothes, the energy consumption can be significant.  The major consumer of energy in clothes washing is normally the heating of the water used.  In fact, if you normally do a wash load at say 130 degrees F, your energy consumption is actually 60% greater than if you used 85 degrees.  Further, with the availability of many cold water laundry detergents which use  environmentally green formulas, there is no need to ever use water above 85 degrees.

Another aspect of the home laundry energy usage is the nature of the hot water system in your home.  In one extreme is the typical old-fashion poorly insulated electric hot water tank.  In a climate like Bethesda, the energy consumption of such a tank can be up to 25% of total household energy usage.  Highly efficient modern, especially natural gas, hot water heaters can significantly cut down on energy usage versus the typical tank, perhaps 50% or more.  Of course, if you use 100% solar to heat your hot water your energy usage is virtually zero.

So, here again by paying attention to a routine household activity you can promote sustainability by dramatically reducing energy usage to perform the simple act of cleaning your clothes.  Saving energy for the same material outcome is the very definition of sustainability. And by optimizing the efficiency of your hot water tank and always washing clothes at 85 degrees or less you could potentially save about 5-10% of your total household energy costs even without the use of solar derived hot water.

Richard M. Goodman, PhD, is a chemical scientist and consultant focusing on how surface science concepts can solve real world problems.  The periodic column considers aspects of sustainability from a scientific perspective. See Goodman’s profile with Association of Consulting Chemists and Chemical Engineers (ACC&CE) at