### Question
What does furnace mean?


### Answer
**Furnace** has the following meaning in *42 U.S.C. § 6291*:

> a product which utilizes only single-phase electric current, or single-phase electric current or DC current in conjunction with natural gas, propane, or home heating oil, and which—


(A) is designed to be the principal heating source for the living space of a residence

#### Citation:
  - *42 U.S.C. § 6291*
  - Heading: **CHAPTER 76-AGE DISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS > SUBCHAPTER III-IMPROVING ENERGY EFFICIENCY > Part A-Energy Conservation Program for Consumer Products Other Than Automobiles**

