This is probably what has been costing me an extra 17p per wash for a couple of wash loads. Scent boosters used on the Auto Optimal Wash+/AI Wash programme.
A few weeks ago, I was washing about 5kg of mixed clothing on the AI Wash programme on my Series 8 Bespoke AI. Persil Colour Liquid and Comfort Pure conditioner was used and the result was great, but I wondered why the machine detected heavy soiling, washed for 2 hours instead of 1 hour 37 mins when nothing was heavily soiled.
I remembered that I used scent boosters - Fairy Fresh in wash scent boosters and that could've tricked the sensors. Rather recently, I took out a dosing ball, poured 35ml of warm water and added 4 beads of the scent boosters.
The result... cloudy water within minutes. Yep. These little beads of perfume are the culprit. They make the water cloudy and the machine thinks the clothes are dirty.
Turbidity sensors work by emitting a green laser from one end and detecting the transmittance rate on the other end. The sensor itself is quite small but is a nice feature to have in a washing machine.
Scent boosters make the water cloudy. An extra rinse isn't a massive pain since I live in Scotland where the water charge is fixed (included in the council tax). An extra 0.5kWh though is annoying in this day and age for everyone. 32.3p is the unit rate per kWh where I live, and I have a rather energy efficient Hotpoint FDUD dishwasher and mainly LED lights so it isn't too bad, but still pricey.
The washing machine - WW11BB944DGHS1 - tends to maintain the water temperature at around 40⁰C on the AI Wash. That's some unnecessary energy usage there, and when heavy soiling is detected by the turbidity sensor, energy consumption increases by around 0.5kWh, unnecessary detergent gets dispensed, and water gets added.
Not only does the machine have to heat the water throughly again to reach 40⁰C, it also maintains the temperature as it normally does on the programme.
Automation and AI will never be perfect I guess. That said, 2020 and 2022 Samsung washing machines are still incredible. Never did I think around 3kg of bedding and towels could get washed on a Cottons 60⁰C programme using just 1kWh.
I'm glad that scent boosters are only additives, and it's easy to only use conditioner.
