ABSTRACT
This chapter describes efforts beginning in 1979 to develop and market the “NightSky” roof-based cooling system. Designed under the influence of Harold Hay and the Skytherm house, the “NightSky” system was developed beginning in 1979 as a “cooling-only” system that takes advantage of evaporation as well as radiation to the night sky. The initial version placed a water layer on a level roof and used top-coated panels that either floated on the water or were supported on stand-offs just above the water. In this version, a pump sprays water from below the panels uniformly over the top surfaces to cool the water back through the unsealed panel joints, staying below the insulation in the daytime. A California Energy Commission grant helped further develop the system, culminating in 1992 with a large prototype on an existing state building. Real adventure began late that year with a business incubator start-up, followed by 10 more projects over the next six years, and addition of a second version that cools water on the roof but stores it below the roof in an insulated container. This chapter shares the pain and progress of the attempts to surmount market hurdles and implement this simple dry climate cooling technology. After a long dry spell, “NightSky” now shows renewed promise as an integrated system for cooling, rainwater collection, and photovoltaic panel washing.
