I have slightly inclined (50 cm over 6 meters) metal roof over my studio. The roof has bad thermal insluation -- 15 cm of mineral wool between sheet metal.
The location is Kiev, Ukraine. Ambient temperatures extremely rarely exceed 32 °C, and most of the activities in the studio occur after 6 p.m., when it's never over 30 °C. I lived through a year without AC, with only fans for air intake and circulation.
With ventilation turned off the hottest time inside is 7 to 8 p.m.. With ventilation on, and 20 people inside the temperature inside is 1-2 °C more then ambient air.
I want to cool the inside for a few degrees by pouring a water on the roof. My questions are:
- Can I hope for outside roof surface to get as low as a wet-bulb temperature? The graph gives me 25 °C at warmest hour of ambient 32 °C 55 % humidity.
- Which method of water distribution is more effective:
a) Drip tube. Would be easiest to install. The drawback being the risk of water joining into a few streams instead of uniformly wetting the surface.