### Question
How is the "light pipe" defined?


### Answer
The term **light pipe** is defined in *42 U.S.C. § 17173* as follows -

> a device designed to transport visible solar radiation from its collection point to the interior of a building while excluding interior heat gain in the nonheating season

#### Citation:
  - *42 U.S.C. § 17173*
  - Heading: **CHAPTER 152-ENERGY INDEPENDENCE AND SECURITY > SUBCHAPTER V-ACCELERATED RESEARCH AND DEVELOPMENT > Part A-Solar Energy**

