Less water than a wash cycle

INTRO

 

            How much water does your washing machine use every cycle? While doing some laundry the other day, I realised I had no idea—I had never even given much thought to it. It can be easy to take the technology that surrounds us for granted, to forget that the water, gas, electricity that is pumped into our homes has to come from somewhere. As far as my brain was concerned, my washing machine may as well have been a magical box that mysteriously transforms dirty clothes into clean but damp ones.

            It’s the same with the clothes we wear. It takes huge amounts of water to dye our clothes, and fabrics like cotton require even more water to grow. Yet, because there is no sign that the final garment needed any water to create, we never think to consider the water cost of our clothing. Every time I realise my ignorance of what goes into something I consume, I feel a little like a child in a supermarket who is realising for the first time that a frozen chicken comes from a farm animal, not a store shelf.

            So, for this week’s Deep Dive, I thought I would explore just how much water is needed to dye our clothes, and to wash them…

Working out the average

               

Luckily, I’m not the only one asking this question. A blog called In The Wash (https://inthewash.co.uk/washing-machines/how-much-water-does-a-washing-machine-use/) made a post recently comparing the water use of 54 popular UK washing machines.

            They found that the average washing machine uses 48.8 litres of water per cycle. However, this figure isn’t that useful for our purposes, because washing machines with a higher capacity tend to use more water per cycle (although they tend to be more efficient when looking at water used per kilo).

            Thankfully, In The Wash have also considered this, and have provided average figures for each capacity of washing machine: for instance, the average 7kg capacity washing machine uses 43.6 litres per cycle, while the average 14kg machine uses 62.3.

            I’ve put their figures in the middle column of the table below.

               

 

               In the column on the right, I’ve also worked out the litres per kilo of capacity by dividing the water consumption per cycle by the capacity. As you can see, the larger capacity washing machines are more efficient, despite using more water per individual cycle.

            I’ve also averaged these figures to find the average water consumption per kilo of clothing—a figure that I will refer back to later…

 

WHAT about dyeing clothes? exaust dyeing vs *clean color

                          Laundry isn’t the only link between our clothes and water consumption, however. The primary dyeing method used by most textile factories (exhaust dyeing) involves soaking textiles in huge vats of water and chemicals, requiring a lot of water and producing large amounts of polluted waste water.

            So how much water is used to dye the fabrics used to make our clothes? And how does this compare to the water needed to wash them?


            According to research by BluWin, exhaust dyeing (the most common method of dyeing used in many textile factories) consumes 72 litres of water per kilo of fabric being dyed. If we divide this by the figure we worked out in the previous table for the water consumption per kilo for the average UK washing machine (5.17 l/kg) we can see that exhaust dyeing uses almost 14 times as much water per kilo as the average UK washing machine.

            Exhaust dyeing isn’t the only method of dyeing, however. Green Universe is pioneering an innovative new dyeing method that uses far less water than traditional methods—CleanColor. Compared to the 72 litres per kilo of exhaust dyeing, CleanColor only uses 3.95 litres. That’s 0.76 times as much as the average UK washing machine.

           

            In other words, with CleanColor it takes less water to dye a kilo of fabric than it does to wash the same amount.

            And if we think back to earlier in this post, you’ll remember that a single wash cycle from the average washing machine uses 48.8 litres. If we divide that by our figure of 3.95 from the table above, we get 12.35 kilos.

            To put it simply, CleanColor can dye 12.35 kilos of fabric for the same amount of water as a single load of laundry from the average UK washing machine.

           

            Exhaust dyeing couldn’t even dye a single kilo of fabric with the same amount of water—it could only dye roughly 2/3rds of a kilo.

CONCLUSION

I hope you’ve enjoyed this Deep Dive into the water consumption of washing machines and dyeing. Like most people, it wasn’t a question I’d thought to ask until now, but it puts the water consumption of different dyeing methods into perspective in a way that’s easier to grasp.

            Honestly, I was pretty surprised that we can now dye fabric for less water than it takes to wash it—but that shows how impressive some of the innovation going on in this sector really is.

 

Sources:

 

How Much Water Does a Washing Machine Use? (UK)

 

https://www.greenuniverse.life/wp-content/uploads/2023/06/FINAL-LCA-Clean-Color-Tech-vs-Exhaust-Dye-May-2023-1.pdf

 

https://www.wri.org/insights/apparel-industrys-environmental-impact-6-graphics