Friday, 23 October 2020

How much water do we use washing our hair?

A friend told me yesterday her lodger spends 20 minutes in the shower each day - but she has long hair. (We were discussing the pros and cons of solar hot water panels). Since I have short hair I am very quick in the shower which I like because it means I have more time for other things. In addition, less time in the shower means less use of water and energy to heat it. Both water and energy are valuable and water can be scarce at times. If you already have efficient toilets it is quite likely that your biggest water consumption is the shower. Try my water calculator to check. So how much water and energy do we use washing our hair? How does this compare to our overall consumption?

Please fill in my survey
It is difficult to find good data on hygiene habits so I have compiled a short anonymous survey. If you wash your hair in the shower please fill this in. In the meantime, here are some estimates and suggestions for how we can be more efficient with washing our hair.

How much water for a shower?
Average domestic water consumption in the UK is 140 litres/person/day. A standard gravity shower uses around eight litres/minute. At that rate my friend's lodger's 20 minute shower uses 160 litres: more than the average total consumption. That is obviously not typical and I believe most people spend between five and eight minutes in the shower. Here is a table showing how much that uses.

20 mins.standard shower head160
5-8 mins.standard shower head40-64
5-8 mins.low flow shower head30-40
3 mins.low flow shower head18
-wash at the basin (not washing your hair)4-6

How long does washing your hair take?

One of the reasons some people take a long time in the shower is to wash their hair. If you have long hair it can take a minute or two just to wash and rinse once. However, conditioners often recommend leaving them on for a minute or two to take effect. If you do this in the shower with the water running, this adds several minutes to your water use, unless you turn off the water during this time. Remembering when I used to have long hair, I did not turn off the water because I would get cold.

A possible solution - a second towel?
Perhaps there is a solution to this which is to have a second towel. You could turn off the water and wrap yourself in one towel to keep warm while you apply the treatment and wait for it to work. Then take the towel off while you rinse. At the end you still have a nice dry towel for finishing off.

Further reading
Saving shower time saves money too. It is surprising how much water costs, never mind the heating. I wrote about this a few years ago: How much does your bath or shower cost.

Also you might like these previous posts of mine:

And for why water is a particular issue in Cambridge: see Transition Cambridge: When the streams dried up.

Please don't forget the survey (if you wash your hair in the shower). I will tell you the results when I get a reasonable number of responses.

1 comment:

  1. Some people (some quite glamorous ones too) have given up shampoo - and so hair washing altogether (maybe using an egg for washing once a month?!) A step too far for me I fear!


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