Differences Between Thermal vs ULV Foggers – Which Is Best?

Oriole thermal foggers,use heat to vaporize a fogging solution and spray it out as a visible fog cloud with a .05–10-micron range particle size.  Thermal foggers are equipped with a heat barrel that is preheated to high temperatures using propane, gas, or electricity depending on the type of fogged.  When the liquid fogging solution is pumped into the heat barrel it is instantly vaporized. This allows the fogger to produce large count of particles in extremely small size, which all together forms a dense cloud of fog which resembles smoke.  Thermal foggers produce smaller particles which means they take longer to fall to the ground.   The smaller thermal fog particles are useful if you are spraying for mosquitoes, as the longer the particles are suspended in the air, the more likely they are to contact the mosquitoes. However, the near invisible fog generated by a cold fogger may be better suited for neighborhoods where the highly visible smoke produced by a thermal fogger may cause alarm.   Cold foggers are quieter than thermal foggers.

Oriole cold Foggers or Ultra low Volume (ULV) foggers provide a cold fog with particle sizes in the 5-20 micron range.  Cold foggers use air pressure to atomize the insecticide and are powered by gasoline, compressed air, or electricity.   The lack of heat (and thus the fire risk) makes the ULV fogger safer for indoor use.  Both thermal foggers and ULV or cold foggers may be used inside or outside and both can fog water or oil-based products.   Sanitizers, disinfectants, mold, and fungi control products are most often applied by cold foggers which allow adjustment of the particle size and provide larger particles used for these applications.  Research data indicate ULV fog is best for indoor control of stored product insects (beetles, moths, etc.). The optimum particle size theory plays an important role in the use of ULV fogging equipment for insect control.  Droplets of pesticide found to be most effective are those with a small size range allowing them to remain airborne for a considerable length of time and to be carried to the insect by atmospheric transport.  Once a droplet reaches an insect, a final requirement is that it impinge (stick) on the insect.