When you depress the trigger of an air duster, the propellant inside expands rapidly from aliquid state to a gas. This expansion is an adiabatic process, meaning no heat is exchangedwith the surroundings. The cooling experienced is due to the Joule-Thomson Effect, wherethe temperature of a gas changes as it expands at constant enthalpy (H). Most gases,including the ones in air dusters, cool upon expansion under normal ambient conditions.

Yes, air duster is generally designed for use on electronics surface.

Sure you can. The bottles came empty due to shipping, you can contact with us for refunding or a replacement.