The Solar Misting controllers may be used to cool roofs in many applications. The following pictures show one of several Target distribution centers where trucks were previously too hot to load during the day. This roof cooling system allows workers to enter the trailers in the heat of the day and keeps super-heated air from entering the warehouse when the loading doors are opened. The same Solar Roof Cooling principle can be applied to manufacturing buildings; sheds for cows, pigs and poultry; mobile homes; and other structures. Evaporating water, isntead of dumping it down the sewer, may also reduce sewer charges.

This Solar Roof Cooling is accomplished without raising humidity inside the structures, unlike evaporative cooling systems. Solar Roof Cooling is effective even in high-humidity climates because the micro-climate near the super-heated roofs is very dry. The greatly lowered relative humidity at the roof boundary permits rapid evaporation which results in rapid removal of heat from the roof. Solar Roof Cooling removes heat before it radiates into the building, thus reducing the internal cooling requirements. Cows,pigs and poultry under a hot metal roofs are often heated more by radiation from the roofs than by the ambient air.

Note the spray head and cooling spray over the trailer in the photo above. Also, note that water is keeping the concrete cool, but not flooded. Non-flooding and cooling water is applied to the roofs of the trailers and the concrete. The valves and spray heads are installed on the 12" rain guard running above the loading doors. Each valve controls 3 spray heads. PVC plumbing with UV inhibitors (sometimes called Brown Line pipe) was used. This photo is taken facing west in mid-morning.

The On-Time programmed for each spray zone of the Solar 12 equals the time for the spray head to rotate over the trailers once. The Solar Repeat Intervals programmed into the Solar Misters are adjusted so that water runs down the roof of the trailers, drips on the concrete and runs away from the trucks about 6-8 feet before evaporating. At noon, the roof cooling cycle repeated about every 10 minutes. As the sunset, the repeat interval stretched to every 1/2 hour. This automatic change in the repeat interval provide cooling without flooding.

In the first installation at Target, it was found that roof cooling started too early in the morning when everything was still cool. To delay the roof cooling until the trailers began to warm, a simple thermostat was installed under the rain guard and set between 80F to 90F. This thermostat was then spliced into the common wire that carried the 24VAC from the Solar 12 to the valves. When the temperature was below the set point of the thermostat, then the thermostat blocked the voltage from the Solar 12 to the valves. As the temperature rose, then the thermostat closed its contacts and allowed the Solar 12 to activate the Solar Roof Cooling system.

The photo below is taken facing northwest. One Solar 12 controls six valves which are cooling the east loading docks (shown below) and 6 valves which are cooling the loading docks on the west side of the building. Another Solar 12 controls 12 valves which are cooling the long south facing docks which are shown running to the right in the distance in the photo below. In the corner where the two buildings meet, you may be able to see the spray of another zone against the shadow of the south facing building.

The LX5 Solar Sensor shown below is mounted above the south wall to give the Solar 12 the best look at the boiling sun. It is one of two Solar Sensors on the site.