Water & carbon saved by not using a pre-wash
According to a report by Ariel and the UK NGO Waterwise,
Britons waste a staggering 6 billion litres of water every year simply by using the pre-wash setting on their washing machines.
Each cycle can use between 8 and 15 litres of water, in many cases unnecessarily as modern detergents and washing machines are pretty good at getting our clothes clean, and there are other more effective ways of spot-treating garments which are marked or stained. Using the setting also wastes electricity, with each cycle lasting between 12 and 17 minutes or more.
Carbon saved by not using a pre-wash
A pre-wash cycle can run for between 12 and 17 minutes (and in some cases longer) so taking an average running time of 15 minutes.
An average washing machine uses 1.2 kWh or power so for a 15 minute pre-wash cycle: 15/60 x 1.2 = 0.3 kWh
Using our grid electricity carbon conversion factor of 0.527 kg CO2 emitted per kWh
The carbon emitted per pre-wash cycle is:
0.3 x 0.527 = 0.16 kg CO2 per cycle, or 8.32 kg CO2 per year.
Alternatives to pre-washing
Most people pre-wash if their clothes are marked in some way, and spot-treating the problem can be a more effective solution than pre-washing. Here are some tips:
Ecostreet tips for eco-friendly stain removal
http://ecostreet.com/blog/eco-friendly-house/2007/11/22/eco-friendly-stain-removal-its-easy-when-you-know-how
The Vinegar Institute - using vinegar in your laundry
http://www.versatilevinegar.org/usesandtips.html#2
Tip the Planet
http://www.tiptheplanet.com/index.php?title=Eco_friendly_stain_removal_tips
Footnotes
