PPD Flashcards
(262 cards)
A balanced air valve positioned so as to admit air to the flue or stack of a furnace in order to maintain a constant about of draft. Also called a draft regulator.
barometric damper
Curved baffles inserted in a duct elbow to decrease pressure loss through the elbow
turning vanes
The basic unit of electrical power, equal to volts x amperes in direct current systems. Equal to 3.41 Btuh
watt (W)
A sound wave that has been reflected with sufficient magnitude and delay so that it is heard as a distinct from that transmitted directly
echo
A pipe fitting used to couple the ends of two pipes, neither of which can be rotated
union
The logarithmic expression for the acoustical power at the source of a sound. Also known as acoustic power level.
power level (pwl)
A device used to collect solar radiation
collector
PPM
parts per million
Parts other than valves or pipe used in a pipe line such as couplings, elbows, tees, unions and reducers.
fittings
intensity level
The intensity of sound at a given location, measured in watts/ sq. meter, or more commonly in dB where the reference level is 10-12 watts/ sq. m
A measure of the tendency of an electrical circuit to restrict the flow of current, or the ratio of voltage to current in a conductor or closed circuit. Unit= ohm
resistance
The intensity of light falling on a surface usually expressed in footcandles.
illumination
The velocity of air in an enclosed space measured in feet/min
air movement
A water seal fitting located in the drain line after a fixture to prevent sewer gases and odors form entering the room.
trap
The amount of light emitted by a source
luminous intensity (I)
An outside faucets for connecting to a garden hose.
sill cock
Water containing so much salt that it is non potable.
brackish
A pump used in hot water systems for maintaining forced circulation of water or other liquid.
circulator
Fire assembly
A complete fire-resistive assembly consisting of a fire door, fire damper or fire window and its mounting frame and hardware.
An absorption or drain field in which septic tank effluents seep through loose pipes and coarse aggregates into the surrounding soil.
leaching field
A set of electrical conductors which extend from the source of energy to a distribution center.
feeder
Forced convection
The movement of a fluid by a fan or a pump in order to force heat exchange.
The leakage of air through cracks around windows and other building elements.
infiltration
The ratio of the moisture content of the air to the maximum possible moisture content at the same temperature.
relative humidity (RH)