Washing your clothes in hot water?

A full 90 percent of the energy used in washing clothes goes toward heating the water, so it stands to reason that using less energy by washing in cold, unheated water would create significant environmental savings. But just how much difference are we really talking about?

TreeHugger did the math, and came up with some pretty interesting results. It turns out that pressing the cold/cold button (instead of the hot/warm button) on your washing machine has the same impact as...

...driving about 9 miles in a car or the production, transportation and storage of a six pack of beer. It may not be too surprising that one load of laundry doesn't make a huge amount of difference compared to, say, not eating meat or dairy. But, multiply those impacts by 392 -- the number of laundry loads an average U.S. home washes in a year -- and, all of the sudden, there are some real impacts.

Washing laundry in hot water is really wasteful
To wit: Washing every load on the hot/warm cycle (in a top loading machine and an electric water heater) for a year is equivalent to burning about 182 gallons of gasoline in a car; in an average (19.8 miles per gallon) car, that'll get you around 3595 miles. So, wash in hot/warm, or drive almost 3600 miles -- same difference.

Similarly, if you wash with the hot/cold cycle (in a top loading machine and an electric water heater), you'll end up with 2407 pounds of CO₂ per year -- just over a metric ton -- which is equal to about one round-trip cross-country flight (6171 miles of long-haul flying).

What does this all mean? Aside from being a great example of how little decisions add up to make a big difference, it shows how wasteful heating large quantities of water can be. Just selecting the "cold/cold" cycle has the potential to save as much CO₂ emissions each year as thousands of miles driven in a car, or even an airplane flight or two.