Want to keep your house cool this summer? Install solar panels.

A team of researchers from the University of California at San Diego have determined that solar panels keep a building’s roof cooler by 5 degrees Fahrenheit compared to a roof without solar panels, and they also kept the building warmer at night.

Jan Kleissl, a professor of environmental engineering at the UC San Diego Jacobs School of Engineering, led the research team.

Kleissl and his team of students gathered data over three days using the roof of the Powell Structural Systems Laboratory at the Jacobs School of Engineering as their lab, and using an infrared camera to see what spots of the roof and ceiling were coolest.

The building is equipped with solar panels, some tilted and some flushed. Some portions of the roof were not covered by solar panels.

The panels act as roof shades, according to Anthony Dominguez, the graduate student lead on the project. Instead of the sun’s rays warming the roof’s building and then that heat being pushed through the roof and into ceilings, the solar panels take on much of the heat.

This heat is then removed by wind blowing between the solar panels and the roof. In instances where there were gaps between the roof and the panels, as with the tilted panels, more cooling was actually provided.

While only using three day’s worth of data, Kleissl is confident their methodology can allow people to determine the cooling effects of solar panels over the course of a year.

The study was funded by a NASA Graduate Student Research Program fellowship. Kleissl’s research is funded by the National Science Foundation, California Public Utilities Commission, the Department of Energy and the California Energy Commission.

The study will appear in a forthcoming issue of the journal Solar Energy.