Laundry: the most automatable chore in the house

Laundry is the most automatable household chore, because it consists of long unattended machine cycles with clear start and finish points, it uses a lot of energy and water, and the failure mode — forgetting a wet load — is annoying rather than dangerous.

It is also where a small amount of sensing produces a disproportionate improvement in daily life. Here is the practical version.

The single best automation: knowing when a cycle ends

Damp washing left in a drum for a day smells, needs rewashing, and wastes everything the cycle used. It is the commonest laundry failure and it is entirely solvable.

A metering smart plug on the machine gives you this on any washing machine, connected or not. The pattern to detect: power was above a threshold for a while, then dropped below a low threshold and stayed there for two or three minutes. The delay matters, because machines pause between phases and a naive rule fires early.

Two refinements worth adding. Notify the right person, or everyone, rather than only whoever set the automation up. And repeat the reminder after thirty minutes if the door has not been opened, which is what actually gets the load moved. A door contact on the machine closes that loop nicely.

Where a plug is impractical — a hard-wired machine, or an awkward socket — a vibration or accelerometer sensor stuck to the casing detects the cycle instead, and works on anything that shakes.

Energy and water, honestly

Most of a washing machine's energy goes into heating water, so temperature is the dominant variable.

Washing at 30 rather than 40 °C uses noticeably less energy, and modern detergents are formulated for it. Most everyday laundry is not dirty in a way that needs heat.

But run an occasional hot cycle. A machine used only at low temperatures develops biofilm and smells, and towels and bedding benefit from 60 °C for hygiene reasons — particularly if anyone in the house has been ill, or for allergy management, where 60 °C is what kills dust mites rather than merely rinsing allergen away. A monthly maintenance wash at 60 or 90 with an empty drum keeps the machine clean.

Eco cycles use less energy and water and take longer, because they compensate for lower temperature with time. This confuses people: the long cycle is the efficient one. On a time-varying tariff, a longer cheaper cycle overnight is doubly sensible.

Fill the machine properly. A half load uses most of the energy of a full one. Two half loads cost roughly twice one full load.

Spin faster if you tumble dry. Every extra bit of water removed mechanically is water the dryer does not have to evaporate, and mechanical extraction is far cheaper than heat.

Drying, which is where the real energy is

Tumble drying is one of the most energy-intensive things a household does, and the type of dryer matters enormously.

Vented dryers heat air, pass it through the clothes, and blow it outside. Simple, cheap, and the least efficient by a wide margin.

Condenser dryers recover the moisture rather than venting it, and are somewhat better.

Heat pump dryers recycle the heat as well as the moisture, using a fraction of the energy of a vented machine. They take longer and cost more to buy, and over a decade of use the arithmetic generally favours them clearly for a household that dries frequently.

And the honest observation: drying outside is free, and drying indoors on a rack is not free at all — it releases litres of water into the house, which is the largest avoidable moisture source in most homes and a direct cause of condensation and mould. If you must dry indoors, do it in one room with the door closed and the extractor or a dehumidifier running, rather than distributing the moisture through the house.

A dehumidifier in a closed room with a fan is, incidentally, a surprisingly effective and reasonably efficient way to dry clothes indoors — considerably better than a rack in the living room.

Shifting laundry into cheap hours

A washing machine is a textbook flexible load: it does not matter when it runs, only that it is finished when you need it.

Use the machine's own delay start if it has one, which most do, and set it to land in the cheap window. This needs no smart anything.

Or use a smart plug on a machine loaded and set to start when powered — check yours resumes rather than needing a button, since many do not.

Or use built-in connectivity where the machine supports it properly.

Two courtesy points. Noise matters if you share walls, and a spin cycle at 3am is how neighbour relations deteriorate. Aim for late evening or early morning rather than the middle of the night in a flat. And consider fire risk: appliance fires are rare but not unknown, and running a tumble dryer unattended overnight while everyone sleeps is a risk some people reasonably decline. Washing machines are a lower concern than dryers.

Sensors worth putting in a utility room

A leak sensor behind the machine. Non-negotiable. Flexible supply hoses are consumables under permanent mains pressure, and when one fails it delivers water at full flow into a room nobody looks at.

A metering plug for cycle detection and energy figures.

A humidity sensor, especially if you dry indoors, driving an extractor or a dehumidifier on a relative threshold.

A temperature sensor, since utility rooms are frequently unheated and contain pipework — a freeze alert here is well placed.

A door contact on the machine, so you know when the load was removed.

A vibration sensor, which besides detecting cycles will tell you if a machine has started walking across the floor because the load is unbalanced or a foot has moved.

A laundry setup

1. Leak sensor behind the machine, and replace hoses older than five years.
2. Metering plug with a cycle-complete notification, delayed two minutes and repeated after thirty.
3. Wash at 30 °C normally, with a hot cycle for towels, bedding and monthly maintenance.
4. Use eco cycles and understand that the long one is the efficient one.
5. Spin faster if you tumble dry.
6. Dry outside where possible; indoors, use one closed room with extraction or a dehumidifier.
7. Schedule into cheap hours, avoiding the middle of the night if you share walls.
8. Clean the dryer filter every single cycle.

Items one, two and eight are the three we would insist on: one prevents a flood, one prevents a rewash, and one prevents a fire.