- Difference based on the fog volume emitted
- Dry fog droplets are 10-15 microns
- Wet fog droplets are 20-30 microns
Anything over 30 microns is classified as a mist or a spray

Difference between thermal and cold or ULV (ultralow volume) foggers

- ULV (ultralow volume) foggers are typically used indoors
- Cold or ULV foggers are typically wet because of their droplet size (20 or more microns)
- Thermal foggers are typically dry because of their droplet size (10 microns)
- Thermal foggers are ideal for large areas
- Cold foggers allow you to regulate both the spray and droplet size with a range typically between 5-50 microns
- Thermal foggers heat up a coil within a metal tube, causing the liquid insecticide solution to vaporize
- Heat from thermal foggers comes from either propane or electricity
ULV foggers produce fog using pressure either by the disinfectant solution being pumped through a high-pressure nozzle or the solution is sent through a vortex of high-speed air, the pressure breaks up the liquid into tiny droplets