nominal length of a rigid duct
[EN 12792:2003, 267]:is the actual length of a rigid duct without fittings or components.
Continue reading →Glossary Terms
nominal size of an air terminal device
[EN 12792:2003, 268]:nominal value of dimensions of the prepared opening (duct) into which the air terminal device is to be fitted.NOTE For an air diffuser the nominal size is generally defined as the duct size into which the neck of … Continue reading →
nominal size of duct and fitting
[EN 12792:2003, 269]:reference dimension used for designation, calculation and application of duct and fitting.
Continue reading →Nominal Time Constant
[AIVC, Air infiltration and ventilation glossary, 1992]:the inverse of specific flow. Under piston conditions the nominal time constant is the time it will take to exchange all of the air in a room or zone with fresh air.(see also air … Continue reading →
non return damper
[EN 12792:2003, 270]:device that allows air to flow only in a predetermined direction.
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