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.
The first, lower stage, of the furnace is like having a low-flame on your gas grill or stove turned on. Nice and quiet. The second (or third) stages of the gas valve open when higher levels of heat are needed, but they also result in a noisier furnace due to the added combustion and higher flame. 1  Single Stage Gas Valves are Louder. 2  Two-Stage or Multi-Stage Furnaces are Quieter.