ActivatedCarbonFilterMonitoring Cluster

Cluster ID: 0x0072  |  Endpoint: Application endpoint (typically Endpoint 1 or a dedicated filter endpoint)

ActivatedCarbonFilterMonitoring monitors the lifecycle of activated carbon filters -- remaining life, degradation direction, replacement reminders, and replacement product information. Its structure is identical to HEPA Filter Monitoring (0x0071) (same attributes, commands, and enums); the only difference is the filter type.

Feature Map

Three optional feature bits determine which attributes the device supports, identical to HEPA Filter Monitoring.

Attribute Overview

All attributes are identical to HEPA Filter Monitoring. The Feature column indicates which feature bit is required.

Condition (Filter Remaining Life)

A percentage value from 0 to 100 representing the remaining adsorption capacity of the activated carbon filter. 100 means brand new; 0 means fully depleted (when DegradationDirection = Down). The degradation rate of activated carbon depends on the concentration of VOCs/odors in the environment; it is consumed faster in high-pollution environments.

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DegradationDirection (Degradation Direction)

Tells the app the meaning direction of the Condition value.

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ChangeIndication (Change Indication)

The device's overall assessment of the filter's current status. Mandatory attribute -- must be implemented even without the CON Feature.

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InPlaceIndicator (Filter Installation Status)

true indicates the filter is correctly installed; false indicates the filter is missing or improperly installed. Devices with physical detection switches can automatically update this value when the user removes the filter.

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LastChangedTime (Last Changed Time)

Unix timestamp (seconds) recording when the activated carbon filter was last replaced. Combined with Condition, it allows calculation of actual usage days and average consumption rate. After the user replaces the filter and executes the ResetCondition command, the device should update this value.

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ReplacementProductList (Replacement Product List)

List of replacement filter products recommended by the device. Each entry contains a product identifier type and value. The app can use this to directly guide users to purchase.

ProductIdentifierTypeEnum Enum Values

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Commands

Only one command, used to reset the state after filter replacement.

ResetCondition -- Reset Filter Status (0x00)

After the user replaces the activated carbon filter, this command is sent via the app. Upon receipt, the device should restore Condition to 100 (or 0, depending on DegradationDirection), reset ChangeIndication to OK, and update LastChangedTime to the current time. No parameters required; send directly.

Request example:

{
  "invokeRequests": [{
    "commandPath": {
      "endpointId": 1,
      "clusterId": "0x0072",
      "commandId": "0x00"          // ResetCondition
    },
    "commandFields": {}
  }]
}

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Example Data

Read the activated carbon filter status from an air purifier:

{
  // --- Attributes (ActivatedCarbonFilterMonitoring Cluster) ---
  "0x0": 72,          // Condition = 72% (filter remaining life)
  "0x1": 0,           // DegradationDirection = Down (lower value means more replacement needed)
  "0x2": 1,           // ChangeIndication = Warning (replacement recommended)
  "0x3": true,        // InPlaceIndicator = true (filter installed)
  "0x4": 1718380800,  // LastChangedTime = 2024-06-15T00:00:00Z
  "0x5": [{           // ReplacementProductList
    "productIdentifierType": 3,
    "productIdentifierValue": "AC-FILTER-2024-VOC"
  }]
}

Usage Scenarios

{
  // Endpoint 1 -- HEPA Filter (HEPAFilterMonitoring 0x0071)
  "hepa": {
    "0x0": 45,         // Condition = 45%
    "0x2": 1           // ChangeIndication = Warning
  },
  // Endpoint 2 -- Activated Carbon Filter (ActivatedCarbonFilterMonitoring 0x0072)
  "carbon": {
    "0x0": 78,         // Condition = 78%
    "0x2": 0           // ChangeIndication = OK
  }
}