Report Number




Radiant Barriers; Buildings


The Florida Solar Energy Center (FSEC) has monitored several automobiles in order to investigate how hot interior temperatures in parked cars might be reduced through the use of improved technology car shades. We observed interior temperatures in un-shaded stationary automobiles in Cape Canaveral, Florida to commonly reach 150° F and dashboard temperatures to rise to nearly 200° F. We found the addition of a conventional cardboard car shade behind the automobile windshield on sunny days to reduce the interior air temperatures by an average of 15° F. Dashboard temperatures were reduced by 40° F.

We found radiant barrier system (RBS) car shades to offer further improvements over conventional cardboard shades. RBS car shades are similar to conventional ones, but have a low emissivity foil backing laminated to the interior facing surface of the shade. When using an RBS car shade, automobile interior air temperatures are reduced an average of 3 - 5° F over conventional shades; the steering wheel and dashboard temperatures are reduced by a further 6 - 11° F. Although a seemingly a modest reduction, this improvement represents approximately an 8% reduction in heat transfer to the car interior during sunny conditions over the use of conventional car shades.

Date Published



Reference Publication: Parker, D.S., "Monitored Performance Enhancement of a Radiant Barrier Automobile Window Shade", Presented at ASES National Solar Energy Conference, March 19­22, 1990, Austin, TX.

Local Subjects

Buildings - Radiant Barriers


FSEC Energy Research Center® Collection



Rights Statement

Copyright Undetermined