soft, raised surface upon cloth, mid-14c., downy plumage, from Anglo-French pyle or Middle Dutch pijl, both from Latin pilus a hair (source of Italian pelo, Old French pel). Phonological evidence rules out transmission of the English word via Old French cognate peil, poil. Meaning nap upon cloth is from 1560s.
Updated 01/08/17. 1  of 06. Gas Furnace Types and Efficiency Ratings BanksPhotos / Getty Images The gas furnace in your home is a critically important appliance and one you depend on to work reliably, efficiently and quietly. 2  of 06. Low Efficiency Furnace: 55% to 72% AFUE (obsolete technology) Characteristics. 3  of 06.
Blast furnace gas (BFG) is a by-product of blast furnaces that is generated when the iron ore is reduced with coke to metallic iron. It has a very low heating value, about 93 BTU /cubic foot, because it consists of about 60 percent nitrogen, 18-20% carbon dioxide, which are not flammable.