Which type of humidification is not commonly used in residential settings?

The type of humidification that is not commonly used in residential settings is the industrial spray humidifier. This type of humidifier is designed for large-scale applications, typically found in commercial or industrial environments where significant humidity control is necessary, such as factories, warehouses, and greenhouse operations.

In contrast, wetted element humidifiers, pan humidifiers, and steam humidifiers are often utilized in residential settings. Wetted element humidifiers use a moist pad that the air passes through, effectively adding moisture to the air. Pan humidifiers are simple devices that utilize a tray of water to introduce humidity through evaporation, and steam humidifiers generate steam and release it into the air, providing an efficient and effective method of increasing humidity.

Each of these types is suitable for the smaller scale and different humidity needs of a home, while industrial spray humidifiers operate on a much larger scale and are configured for environments that require rapid and extensive moisture dispersal not typically needed in residential applications.