The patented process does not use a heat source to generate its UV Dye. Enhanced Smoke. No heat source means that the Cool Smoke produces a high density smoke immediately (no warm up time required) and does not require the use of Nitrogen or other inert gases to prevent possible explosive combustion within the Smoke machine, experienced by some competitors units while testing EVAP systems. The MotorVac Cool Smoke unit features a Dual Mode leak detection feature, allowing for the option of testing for leaks with or without the requirement for smoke at the push of a button.