Building Systems 3 Flashcards Preview

Building Systems > Building Systems 3 > Flashcards

Flashcards in Building Systems 3 Deck (103)
Loading flashcards...
0

halon

A gaseous, fire-extinguishing medium which smothers fires, often used in automatic systems in computer rooms.

1

refrigerant

The fluid used for heat transfer in a refrigeration system.

2

declination

The 23.5° tilt of the earth's axis relative to a line perpendicular to the plane of the Earth's orbit. This tilt is responsible for the seasons.

3

perm

The unit of permeability for a given material, expressing the resistance of the material to the penetration of moisture. One perm is equal to the flow of one grain of water vapor through one square foot of surface area per hour with a pressure difference of one inch of mercury.

4

refrigeration

The extraction of heat from
a substance or an unoccupied space to reduce it's temperature below that of it's surroundings.

5

noise

Any undesired sound, also any unwanted disturbance within a useful frequency band.

6

barometer

An instrument for measuring atmospheric pressure.

7

stack effect

The tendency of a gas or air to rise in a vertical shaft because it's density is lower than that of the surrounding gas or air. It is also called chimney effect.

8

chill factor

A fictitious temperature assigned to a combination of actual temperature and wind velocity which has the same physiological effect as still air at the chill factor temperature. It is also known as wind chill index.

9

diffuser

A device through which the air from a duct enters a room, or a device through which the light from a fixture enters a room.

10

DWV

Abbreviation for drain, waste, and vent.

11

circuit vent

In sanitary drainage, any vent which serves two or more traps.

12

heat of vaporization

The heat given off by a vapor condensing to a liquid, or the heat absorbed by a liquid evaporating to a gas, without a change in temperature.

13

equinox

Either March 21st (vernal equinox) or September 21st (autumnal equinox), first day of spring (or fall), when night and day are of equal length.

14

anechoic room

A room whose boundaries absorb all of the sound striking them. It is also known as a free-field room.

15

barometric damper

A balanced air valve positioned so as to admit air to the flue or stack of a furnace in order to maintain a constant amount of draft. It is also called a draft regulator.

16

turning vanes

Curved baffles inserted in a duct elbow to decrease pressure loss through the elbow.

17

watt (W)

The basic unit of electrical power, equal to the product of volts and amperes in direct current systems, equal to 3.41 Btuh.

18

power level (pwl)

The logarithmic expression for the acoustical power at the source of a sound. It is also known as acoustic power level.

19

collector

A device used to collect solar radiation.

20

PPM

The abbreviation for parts per million.

21

intensity level

The intensity of sound at a given location, measured in watts per square meter, or more commonly in decibels where the reference level is 10-12 watts/meter squared or 10-16 watts/cm squared.

22

resistance

A measure of the tendency of an electric circuit to restrict the flow of current, or the ratio of voltage to current in a conductor or closed circuit. The unit of resistance is the ohm.

23

illumination

The intensity of light falling on a surface, usually expressed in footcandles.

24

noise reduction coefficient (NRC)

A one-number rating system giving the average sound absorption coefficient of a material at frequencies of 250, 500, 1000, and 2000 Hz.

25

sensible heat ratio (SHR)

The ratio of sensible heat to enthalpy (total heat).

26

room resonance

The phenomenon which occurs when sounds in a room that are within a narrow band of frequencies tend to sound louder than sounds of other frequencies.

27

gate valve

A valve consisting of a sliding plate or gate perpendicular to the flow, intended to be fully open or closed.

28

vacuum breaker

An automatic valve which admits air into a supply pipe to prevent siphoning polluted water back into the supply.

29

pilot tube

An instrument used with a manometer or pressure gauge to measure the velocity of air or water in a duct or pipe.