ULV is short for ultra-low volume. A fogging machine uses air to transform large volumes of liquid into fine droplets that can be sprayed into the air.
ULV fog machines are used by businesses and home users to apply payloads like pesticides, herbicides, fungicides, sterilizers, and disinfectants among other liquids and chemicals.
Here is an example of one of these fogging machines that are purchased by to warehouse companies: click here
Some companies in the warehouse business are spraying their premises with disinfectant during the COVID-19 pandemic.
Of course, foggers are also used to spray for pests, turning insecticide not a fine mist so it can be distributed throughout an environment.
Here is a YouTube video that features 7 different fogger products in a side by side comparison:
You will also find foggers on Amazon.com. See the following page: Click here
Learn more about foggers on this page on Wikipedia.