Low-E Coating Detector

Hand-Held Detector for Low-e and Spectrally Selective Coatings

Low solar heat gain low-emissivity coatings offer the potential to reduce unwanted solar heat gains in cooling dominated climates by 40% over clear double glazing and by up to 30% over conventional low-e coatings. Windows employing such coatings are extremely cost-effective technologies for code compliance or incentive programs (i.e. Energy Star homes). However, since these technologies are typically not discernible to the human eye, consumers, builders, utility representatives and others have asked for a simple hand-held detector to determine what type of coating (if any) is used on a double glazed window. With DOE and CIEE co-support, LBNL Windows and Daylighting Group researchers developed a prototype of such a detector. It measures reflectance in the near infrared portion of the solar spectrum (where the different coating technologies have significantly different reflectances). The low cost measuring technique uses an infrared light-emitting diode and phototransistor. The result is displayed by illuminating one of three LEDs giving a simple indication of whether the window is clear, regular low-e, or spectrally selective low-e.

A series of ten prototypes (shown here) have been assembled. These units are currently being tested in the field by various organizations.

The "Instruction Manual" gives information about the operation and use of the device.

For more information on the Low-E Coating Detector contact:

Howdy Goudey
Building Technologies Program
510-486-6046 (fax)