HVAC Fundamentals Flashcards
Enthalpy
Is the property of a body that measures its heat content.
Density
Density=Mass/Volume
Is the mass per unit volume.
Absolute Temperature
The temperature that can be measured and recorded.
Specific Gravity
A temperature measured from absolute 0 in kelvin
Heat
Is the form of energy that transfers from one body to another due to a temperature difference.
Temperature
A measure of the amount of thermal activity in a body.
Specific Gravity
the specific gravity of a substance Is defined as the ratio of its weight to the weight of and equal volume of water at 39 degrees Fahrenheit.
pg.20
Horse Power
A unit of power equal to 550 foot pounds per second.
Boiling Point
212 degrees Fahrenheit at atmospheric pressure. The point at which water boils. This can change at different elevations
pg.32
Atmospheric Pressure
14.7 psi
Saturation
A measure of how much water is in the air.
Saturated vapor is vapor at the boiling temperature. Saturated liquid at the boiling temperature.
pg.35
BTU
British thermal unit. The amount of heat required to heat one pound of water one degree Fahrenheit.
U-Factor
U-Factor=1/R-value. You cannot add U-Factors only R-values. High U-value more heat transfer. The overall heat transfer coefficient.
pg.52
R-Value
Is the thermal resistance of a material. A materials ability to resist the flow of heat.
pg.49
Comfort Zones
Regions regions or combinations of air temperature and humidity where at least 80% of the occupants will find the environment comfortable.
