Is It Dry Yet?

Original Article ↗ Hacker News Discussion ↗

Detecting When Laundry Is Done

  • Popular approach: plug dryer/washer into a smart plug that reports power usage to Home Assistant; trigger a “finished” notification when draw drops below a small threshold for N minutes.
  • Variants discussed: countdown timers that reset while power > X W, excluding short heater cycles; tracking an “operational state” entity (Off / Drying / Finished).
  • Alternatives when power monitoring is impractical or risky:
    • Vibration sensors (Zigbee, YoLink, etc.) stuck on machine; automations fire when vibration starts/stops.
    • Temperature sensor on exhaust duct; alert when temp falls below a threshold for some time.
    • Old hacks: using a laptop’s accelerometer on top of the dryer; or just a mechanical kitchen timer.

Smart Appliances vs DIY Automation

  • Some prefer buying smart washers/dryers that send notifications, noting price deltas of ~€100 over “dumb” units.
  • Others dislike built-in “smart” features: unreliable moisture sensors, incomplete drying, or features locked behind apps.
  • Home Assistant is praised for flexibility (including Apprise notifications), but criticized as complex, YAML-heavy, and poorly documented for simple tasks.
  • Some argue much of consumer IoT is superficial, cloud-tied, and not designed for serious local automation.

Dryers vs Air-Drying

  • Several argue the “smart” solution is to avoid dryers: lines, racks, indoor pulley systems, balconies; lower wear on clothes and no electricity.
  • Counterpoints: hanging is tedious, can cause stiff towels and wrinkles, and is hard in small, damp, or very humid homes (mold, musty smell).
  • Debate over climate:
    • Some say clothes dry fine indoors or even at –20°C; cold air is often dry and sublimation works.
    • Others in cold-and-humid regions report clothes never fully dry and smell bad.
    • Ventless vs vented dryers and home ventilation strongly affect indoor humidity.

Electrical & Safety Considerations

  • Concern about using generic smart plugs with inductive loads; risk of relay damage if switching motors on/off.
  • Some note that if the smart plug never interrupts power (only measures), the risk is lower.
  • Suggestions: high-power smart switches (e.g., geyser-rated), external relays, or avoiding clamps on 240V two-leg circuits unless measuring a single conductor.

Miscellaneous Reactions

  • Some are satisfied with built-in buzzers/jingles; others can’t hear them from basements/garages or while wearing headphones.
  • A subset sees all this as overkill versus a phone/physical timer, while others value the project as fun and educational.
  • The generated cover art drew both praise (aesthetic effort) and critique (large file size, obvious AI style, perceived low effort).