Matching Pairs Air Distribution Systems - section 1Online version Trade terms - Air Distribution Systems - section 1 by Valerie Jimenez 1 Velocity pressure 2 Relative humidity (RH) 3 Psychometric chart 4 Dew point 5 Velocity 6 Total pressure 7 External static pressure (ESP) 8 Wet-bulb temperature 9 Blower door 10 Revolutions per minute (rpm) 11 Pilot tube 12 Static pressure 13 Dry-bulb temperature 14 Cubic feet per minute (cfm) The number of rotations made by a spinning object over the course of one minute. A unit of measure for the volume of air flowing pas a point in one minute. The temperature measured using a standard thermometer. It represents the measure of sensible heat present. The speed that the air is moving. The rate of airflow is usually measured in feet per minute (fpm) The pressure exerted uniformly in all directions within a duct system, usually measured in inches of water column (in. w.c) The sum of the static pressure and the velocity pressure in an air duct. An assembly containing a fan used to depressurize a building by drawing air out, to support duct leak testing. The pressure in a duct due to the linear movement of the air. It is the difference the total pressure and the static pressure. A tool used to take pressure measurements in a moving air stream. Temperature taken that takes into account he moisture content of the air, it reflects the total heat content (sensible & latent) of the air. The temperature at which air becomes saturated with water vapor, and the water starts t condense into droplets; at state of 100% relative humidity The total resistance of all objects and ductwork in the air distribution system beyond the blower assembly. A graphic method of showing the relationship of various air properties. The ratio of the amount of moisture present in a given sample of air to the amount it can hold at saturation. Expressed in percent.