HepaFilterMonitoring Cluster

Cluster ID: 0x0071  |  Endpoint: Application endpoint (typically Endpoint 1)

HepaFilterMonitoring monitors the lifecycle status of HEPA filters in air purifiers, including remaining life percentage, degradation level, whether replacement is needed, and recommended replacement product information. After the user replaces the filter, the state can be reset via a command to begin a new monitoring cycle.

Feature Map

HepaFilterMonitoring uses the Feature Map to control optional feature activation. Devices can declare supported features based on hardware capabilities.

Attribute Overview

HepaFilterMonitoring attributes are divided into required and optional parts; optional attributes depend on the features declared by the device.

Condition (Filter Remaining Life)

Represents the filter's remaining life as a percentage, ranging from 0 to 100. 100 indicates a brand new filter, 0 indicates the filter is fully depleted. Requires the device to declare the CON Feature for this attribute to appear.

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DegradationDirection (Degradation Direction)

Indicates the degradation direction of the Condition value -- whether increasing or decreasing values represent worsening filter condition. Requires the device to declare the WAR Feature for this attribute to appear.

DegradationDirectionEnum Enum Values

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ChangeIndication (Replacement Indication)

The filter's current replacement status. This is a required attribute; even if the device does not support the Condition percentage, it must report the replacement indication.

ChangeIndicationEnum Enum Values

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InPlaceIndicator (Filter Installation Status)

A boolean indicating whether the filter is physically installed in the device. true means the filter is in place; false means it is not installed or has been removed. This is an optional attribute, depending on whether the device has a physical detection sensor.

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LastChangedTime (Last Changed Time)

The UTC timestamp (epoch seconds) of the last filter replacement. Can be null, indicating the device has not recorded a replacement time. After the user sends a ResetCondition command, the device updates this attribute to the current time.

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ReplacementProductList (Replacement Product List)

A list of recommended replacement products; each entry contains a product identification type and value. Requires the device to declare the REP Feature for this attribute to appear. The list can contain multiple entries, identifying the same replacement filter using different coding systems.

ReplacementProductStruct

ProductIdentifierTypeEnum Enum Values

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Commands

HepaFilterMonitoring has only one command, sent from Client to Server (i.e. app to device). Used to reset the monitoring state after the user replaces the filter.

ResetCondition -- Reset Filter Status (0x00)

After the user replaces the HEPA filter, this command is sent to notify the device to restart lifecycle monitoring. Upon receipt, the device resets Condition to 100, ChangeIndication to OK, and updates LastChangedTime to the current time.

This command has no parameters; send it directly.

Request example:

{
  "invokeRequests": [{
    "commandPath": {
      "endpointId": 1,
      "clusterId": "0x0071",
      "commandId": "0x00"       // ResetCondition
    },
    "commandFields": {}
  }]
}

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Example Data

Read all attributes of the HepaFilterMonitoring Cluster from an air purifier:

{
  // --- Attributes ---
  "0x0": 72,          // Condition = 72% (filter remaining life)
  "0x1": 1,           // DegradationDirection = Down (lower values indicate worse condition)
  "0x2": 0,           // ChangeIndication = OK (condition normal)
  "0x3": true,        // InPlaceIndicator = true (filter installed)
  "0x4": 1695206400,  // LastChangedTime = 2023-09-20T16:00:00Z
  "0x5": [            // ReplacementProductList
    {
      "0": 0,         // ProductIdentifierType = UPC
      "1": "012345678905"  // ProductIdentifierValue
    }
  ]
}

Scenario 1: Filter Lifecycle Tracking

The complete flow from installing a new filter to filter depletion and replacement in an air purifier. The app updates the UI in real time by subscribing to attribute changes, and pushes notifications at key milestones.

{
  // Scenario: After 6 months of operation, the filter begins to age
  // First read -- filter status good
  "readAttributes": {
    "0x0": 72,         // Condition = 72%
    "0x2": 0           // ChangeIndication = OK
  },

  // Two months later -- filter enters warning zone
  "readAttributes_later": {
    "0x0": 18,         // Condition = 18%
    "0x2": 1           // ChangeIndication = Warning
  },

  // Continued use -- filter enters critical state
  "readAttributes_critical": {
    "0x0": 3,          // Condition = 3%
    "0x2": 2           // ChangeIndication = Critical
  },

  // After user replaces filter, send ResetCondition command
  "resetCommand": {
    "endpointId": 1,
    "clusterId": "0x0071",
    "commandId": "0x00"
  },

  // Status after reset
  "readAttributes_after_reset": {
    "0x0": 100,        // Condition = 100% (reset)
    "0x2": 0           // ChangeIndication = OK
  }
}

Scenario 2: Replacement Product Purchase Guide

When the filter needs replacement, the app reads the replacement product list from the device to help the user quickly find the correct replacement filter and complete the purchase.

{
  // Scenario: App reads replacement product info to guide user purchase
  "readAttributes": {
    "0x2": 2,          // ChangeIndication = Critical (replacement needed)
    "0x5": [           // ReplacementProductList
      {
        "0": 0,        // ProductIdentifierType = UPC
        "1": "012345678905"
      },
      {
        "0": 4,        // ProductIdentifierType = OEM
        "1": "HEPA-H13-PRO-2024"
      }
    ]
  }
  // App can use UPC code to redirect to e-commerce search, or OEM number to redirect to manufacturer website
}