{
  "id": "emitters:dimmer-switch",
  "collection": "emitters",
  "slug": "dimmer-switch",
  "name": "Dimmer switch and phase-cutting controls",
  "summary": "Phase-cutting dimmers chop the mains waveform and inject harmonics from a few kilohertz up to about 1 MHz onto the building wiring — the classic source of what practitioners call dirty electricity.",
  "status": "verified",
  "lastVerified": "2026-08-12",
  "data": {
    "aliases": [
      "light dimmer",
      "triac dimmer"
    ],
    "category": "dirty-electricity",
    "environment": [
      "home",
      "workplace"
    ],
    "bands": [
      {
        "label": "Harmonics 2 kHz–1 MHz",
        "minHz": 2000,
        "maxHz": 1000000
      }
    ],
    "dutyCycle": "Whenever the dimmed circuit is on and not at full brightness.",
    "distanceProfile": [
      {
        "meters": 0.3,
        "value": {
          "quantity": "electric-field-strength",
          "unit": "V/m",
          "value": 0,
          "basis": "measured",
          "note": "Assessed as conducted harmonic content on the circuit, not as a distance profile. Building-biology practice grades harmonics from 2 kHz–1 MHz more severely than the 50/60 Hz field by a factor of roughly 10–100.",
          "sourceIds": [
            "sbm-2024"
          ]
        }
      }
    ],
    "mitigations": [
      {
        "action": "Replace phase-cutting dimmers with plain switches, or with dimmable LED drivers designed for low conducted emissions.",
        "effect": "Removes the harmonic source rather than filtering its symptoms.",
        "sourceIds": [
          "sbm-2024"
        ]
      },
      {
        "action": "Measure conducted harmonics on the circuit before and after any filter installation.",
        "effect": "Plug-in filters shift and sometimes increase harmonic content; only measurement shows the net effect."
      }
    ],
    "measureWith": [
      "dirty-electricity-meter",
      "oscilloscope-line-adapter"
    ],
    "related": [
      "limits:sbm-2024-electric-bands",
      "glossary:dirty-electricity"
    ]
  },
  "sources": [
    {
      "id": "sbm-2024",
      "title": "Building Biology Evaluation Guidelines for Sleeping Areas (SBM-2024)",
      "publisher": "Institut für Baubiologie + Nachhaltigkeit (IBN)",
      "url": "https://buildingbiology.com/site/downloads/SBM-2024_EVALUATION_GUIDELINES_EN.pdf",
      "year": 2024,
      "kind": "ngo",
      "retrieved": "2026-08-12"
    }
  ],
  "links": {
    "self": "https://emfbase.com/api/emitters/dimmer-switch",
    "html": "https://emfbase.com/emitters/dimmer-switch",
    "markdown": "https://emfbase.com/emitters/dimmer-switch.md",
    "collection": "https://emfbase.com/api/emitters"
  }
}