Washing machine

When Tyson's sister moved overseas earlier this year, she gave us her washing machine. 

Our previous machine was my first ever white goods purchase, to serve a student house share, and at the time it was relatively water and energy efficient. More than ten years later it was valiantly continuing to serve, but was no longer the most efficient option available - and getting a bit small for a family. (How do such little people make such large piles of washing?!)

In addition to using a more efficient machine, we are also using its multiple function buttons to override its less efficient features. We continue to choose cold water every time, and only run the machine if it is full. We also now have control of the spin speed, and (except on very wet winter days) reduce it from the preset 1000rpm to the minimum 600rpm. It is also possible to end the wash completely before the spin cycle is complete, and I do this when I walk past during the spin.

Initial Time: an hour or two relocating the machine 30km across the suburbs and reinstalling.

Initial Cost: zero (big thanks to Auntie L!)

Ongoing time or cost commitment: Clothes takes a little longer to dry if not spun fiercely for the full cycle - but for at least six months of the year (more like nine) they still dry in a day on the outside clothesline in the sun. In wet months I keep the long spin for nappies and heavy items, but short/600rpm spin for other things.

Impact: The advertised energy and water 'stats' of the new machine - an Electrolux EWF10831 - are about the same as the old (310kWhr/yr warm; 130kWhr/yr cold; 68L per wash).

However, the new machine can take 8kg, rather than 5.5kg. This means that the total number of loads is reduced from 5-7 a week to 3-5 a week, and this is where the big saving comes: the machine is using the same amount of energy to wash 45% more washing. Energy ratings are calculated assuming one wash load per day. If we do four loads a week, we use around 177kWhr/yr. If we do six loads a week, we do around 265kWhr/yr. So, we are potentially saving 188kWhr per year, a reduction of 154kg of carbon dioxide. (That's without any alteration to the spin cycle - we could not figure a way to calculate that)

Our observation is that the new machine uses about 60% as much water per wash. We catch the water, so can make a pretty good guess at this. Previously we used around 85L per wash; now we are using around 50L. Allowing for the reduced number of loads, that's a reduction of around 16,000L per year.

Before you race out and replace your washing machine, however, its worth considering the embodied energy involved: the energy (and water) used to manufacture and transport the machine, including the raw materials used to make the machine. In addition to the obvious plastic and steel, washing machines use copper, silver, gold, palladium and platinum. Although mostly used in small quantities in the machine's electronics, extraction of these metals is considered to have high environmental impacts. Even spread over a ten-year working life, the embodied energy in the production of a washing machine has been estimated at around 16% of its total environmental impact, with its disposal after use another 10%. That is, only three-quarters of the 'footprint' of a washing machine is the energy it uses to wash for ten years - the rest is its manufacture and disposal. Another website suggests a twenty-year life span (optimistic!) and has the embodied energy calculated as 5,681,430,000 Joules (1,578kWhr).

Which leads me to: We have a fully functioning 5.5kg front-loader washing machine to give away. If you or someone you know is setting up house or still needing to transition away from a top-loader, and could help spread the embodied footprint of the old machine over a few more working years, please get in touch.

Update: We gave the old machine away using 'GiveIt' and it is now heading for a family in need.

Cold Water Washing

When we bought cloth nappies we considered the instructions about how to wash them somewhat over the top, and scaled our practice down a great deal. However, I did sufficiently listen to their advice to 'wash in very hot water' to set the washing machine temperature to about 35 degrees (Celsius!) - less than half the recommended temperature, but definitely not cold. Recently I decided to try washing the nappies on cold for a while and see if it made any difference. Results: no difference whatsoever to the quality of wash. (Tyson now tells me he has always washed on cold and had no idea I was using hot water) Our washing machine is now permanently set to cold.

Initial Time: Fractions of a second to turn the dial. Several weeks of assessing whether the nappies were really coming clean, but that was testing rather than time taken to make the change.

Initial Cost: Zero.

Ongoing time or cost commitment: Zero.

Impact:  We estimate this is saving about 1.42 units of energy per day (1.42kWh). That's a total of 517 units per year, or 513 kg of carbon dioxide.

This calculation is based on our estimate that a wash uses about 70L, which is about how much we could capture last summer when we were bucketing from the washing machine, if we emptied buckets between the wash and rinse cycles. It takes 1 unit of energy to heat 20L of water by 42 degrees, and water generally starts at around 18 degrees. As cloth nappy users, we wash pretty much every day. 

The information we could find on either the washing machine itself or the web claims our Whirlpool WF665 front loader uses only 307kWh per year to heat an undefined amount of water to 'warm' every day (presumably the hottest setting) and suggests the machine uses somewhere between 55 and 60 L per wash, varying depending on the size of the wash load. Our experience of catching the water, and the physics of heating water, suggest these claims are not accurate. 

It is not possible to calculate accurately how much we are saving if the 307kWh claim is true, as we can't tell how much of that energy is for heating the water and how much for operating the machine. However, newer machines that Tyson has seen through his energy auditing work show energy use for both cold and hot washes, and he says that generally hot washing is rated as using 5-8 times the energy of cold washing. At five times the energy, based on 307kWh per year, changing from hot to cold would be saving us 245.6 units per year (244kg of CO2). Possibly a little less as we were not previously using the highest possible temperature setting.

Its not about the money, but just to give an idea: that's between $60.10 (based on Whirlpool's figures) and $126.51 (our figures) per year at the current cost of electricity.