Air Movement and Measurement Flashcards
The conditions in the atmosphere refer to ______?
Weather
Long-term weather trends for a given region refers to ______?
Climate
How warm the combination of humidity and temperature feels to an occupant of a space is ______ temperature.
Equivlaent
The atmosphere is approximately 23% ______ by weight.
Oxygen
______ makes up 0.03% to 0.04% of the atmosphere and is absorbed by growing plants.
Carbon Dioxide
The majority of the atmosphere is composed of ______.
Oxygen
A gas that is very light and present in most fuels is ______.
Hydrogen
According to Bernoulli’s principle, ______ the velocity of air decreases the pressure
Increasing
Air has weight, volume, and ______?
Temperature
Heat Conductivity
Specific Heat
One pound of air at standard conditions (14.7 psia @ 69.8 degrees F) occupies ______ ft squared.
13.341 ft squared
By dividing the weight of air by the volume it occupies, you can calculate the ______ of the air.
Density
The amount of moisture in an air sample compared to the total amount of moisture the same sample would hold if it were completely saturated at the same temperature defines the term ______.
Relative Humidity
(T/F) Since dry air prevents rapid evaporation of moisture from a surface, the surface does not cool as quickly as it would with moist air.
False
(T/F) The amount of moisture that a set volume of air can hold depends on its air temperature.
True
(T/F) Wet-bulb temperature will be higher than dry-bulb temperature at 100% humidity.
False.
They will be the same
Define dew point.
Dew point is the temperature below which water vapor in the air will start to condensate.
The combined effect of dry-bulb temperature, wet-bulb temperature, and air movement that provides an equal sensation of warmth and cold describes the term ______.
Effective temperature
(T/F) An increase in wind velocity increases heat loss of a heated structure, thereby impacting the efficiency of a heating system.
True
The volume of air flowing through a duct is calculated in ______.
feet per minute
(T/F) Velocity pressure is exerted when the airflow is slowed or stopped.
True
Make-up air is necessary for fuel-burning appliances because oxygen is necessary for ______.
Combustion
Define “Enthalpy.”
The total amount of heat in a substance, calculated from an accepted reference temperature. Specific Enthalpy is enthalpy per unit of mass.
What is heat that brings about a change in state with no change in temperature?
Latent heat
Heat that causes a change in the temperature of a substance is ______.
Sensible heat
