We don't always think in terms of conditioning outdoor spaces but its easy to see the value of making outdoor spaces comfortable for people in an outdoor cafeteria, sports stadium or an event or just a public square where you want to encourage people to hang out in the afternoon. Well, there are options available.
The best option is to provide shade but it's not always feasible and not always sufficient. That brings us to consider misting systems. And yes, we are still talking about evaporative cooling. Introducing fine mist (or tiny water droplets) in the air cause the air to cool down as the mist absorbs energy and evaporates. A typical misting system consist of a series of nozzles connected to a water pipe ususally mounted overhead and a water pump to produce pressure. Water must evaporate quickly for effective cooling and to avoid making everything wet in the vicinity of the system. The water droplets must be very small and the air relatively dry for a successful installation. Another major design factor in selecting a system is water pressure. Low pressure systems are cheaper and usually used in residential applications but they are not as effective as high pressure systems that could produce cooling by as much as 30 degrees Fahrenheit (17 C). High pressure systems are ideal for hotels, sports stadiums and any large outdoor areas that requires cooling.
A smaller and sometimes portable application of cooling by misting is a misting fan which is essentially a misting nozzle mounted in front of a fan.
Several DIY kits are widely available for a reasonable price. Larger systems require better planning but there are good systems available commercially.
If you have used misting systems in any of your projects please share your thoughts here.