Card Set Information
ARE - Building Systems 4.0
British Thermal Unit (BTU)
The amount of heat required to raise the temperature of 1 pound of water by 1 degrees F.
Coefficient of heat Transmission
the overall rate of heat flow through any combination of materials.
the number of BTU per hour that pass through 1 sqft of material of a given thickness when temperature difference is 1 degree F.
the number of BTU per hour that pass through 1 sqft of material 1 inch thick when the temperature differential is 1 degree F.
the temperature at which water vapor in the air becomes saturated and condenses into water drops.
the temperature of the air-water mixture as measured with a standard dry-bulb thermometer.
the total heat in a substance, including latent and sensible heat.
the total solar radiation on a horizontal surface.
heat that cuases a change in state and a change in temperature of a substance.
heat that cause a change in temperature, but not a change of state of a substance.
number of hours need for 1 BTU to pass through 1 sqft of material or assembly of a given thickness when the temperature differential is 1 degree F.
the number of BTUS (joules) required to raise the temperature of a specific material by 1 degree F. Measure of a materials capacity to store heat as compared to water.
the temperature of air as measured with a sling psychrometer.
transfer of heat through movement of a fluid, either gas or liquid.
moisture changes to a vapor
transfer of heat energy through electromagnetic waves from one surface to a cooler surface.
transfer of heat through direct contact between 2 objects of different temperature.
a measure of the power of light perceived by the human eye. Quality of light.
now-obsolete unit which was used to express levels of light intensity in terms of the light emitted by a candle of specific size.
Illuminance. Density of illumination on a surface.
Luminance. A surface that emits 1 lumen per sqft.
L-leaving. Emitting light, giving off light.
il=in. Density of illumination on a surface.
the amount of light produced by a lamp (measured in lumens), as a ratio of the amount of power consumed to produce it, (measured in watts).
increased intensity of sound by mechanical or electrical means.
number of pressure fluctuations or cylces occuring in 1 sec.
unit of frequency. one cycle per second = 1 Hz
the reduction of sound
the persistence of sound in a room after the scource has stopped producing the sound
unit of absorption
noise reduction coefficient (NRC)
sound absorption coefficient
sound transmission class (STC)
sound absorption by a material
3 ways to control sound in a space
reduce the level of the sound scource
modify absorption in the space (materials)
introducing background sound to mask the sound
return of sound waves from a surface.
random distribution of sound from a surface
bending of sound waves around an object or through an object.
the relationship between volts (V), amps (I) and ohms (R)
V = I x R
V=voltate, I=current, R=resistance