LOW PRESSURE MISTING LINE SYSTEMS
Low Pressure Mist Cooling Systems are inexpensive and easy to install. They are great for cooling small to medium sized areas where wetness is not an issue, like swimming pools, fishing piers, sunning areas, etc.
The single biggest issue in mist cooling is residual moisture. Of the 3 kinds of misting systems, only high pressure systems create enough pressure (700 + psi) to flash evaporate the water, so that it evaporates before wetting the surroundings.
Low and mid-pressure systems create a considerable amount of residual moisture (water that does not evaporate before reaching the ground or furniture or people), so they usually get things near the mist line wet.
Whether the residual moisture created by low and mid-pressure systems will be acceptable to you will depend on what the patio is used for, what the flooring consists of, whether there is furniture that will be damaged by moisture, etc.