Noise criteria (NC) translates complex acoustical characteristic into a single quantitative value.
NC level 35 is generally considered acceptable for most library functions, with NC level 40 acceptable in the busier areas (for comparison, NC 20-25 is considered acceptable for concert halls). NC values consider the background noise level traditionally heard from building systems including heating, air conditioning, ventilation, fan units and noise through windows. With increasing numbers of electrical equipment to be found in libraries, increasingly on unmediated public access, consideration of noise must be incorporated into the practice of library atmospherics.
Famous quotes containing the words criteria and/or noise:
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