# Shared Flashcard Set

## Details

Heating Fundamentals 1
Exam #1
35
Other
09/04/2012

Term
 What is heat?
Definition
 The reverse of cold, something that feels warm. Heat is a form of energy, often defined as energy transfer.
Term
 Heat always move from a ________ body to a _______ body.
Definition
 Warmer, Cooler
Term
 Heat is created _________.
Definition
 By the transformation of other types of heat
Term
 Give an example on how heat is created.
Definition
 Mechanical energy turning a wheel, which causes friction creating heat.
Term
 Heat exists at any temperature above _____.
Definition
 Absolute Zero
Term
 How is heat measured?
Definition
 Fahrenheit, Celsius, Kelvin
Term
 Boiling and Freezing Points of the Fahrenheit scale
Definition
 Boiling = 212 deg FFreezing = 32 deg F
Term
 Boiling and Freezing Points of the Celsius scale
Definition
 Boiling = 100 deg CFreezing = 0 deg C
Term
 Define temperature.
Definition
 The intensity of heat (measured in degrees)
Term
 Formula to convert between Fahrenheit and Celsius.
Definition
 5F - 9C = 160
Term
 Changes that take place when heat is added to H2O.
Definition
 1. Rise in temperature (Sensible Heat)2. May melt/vaporize (Latent Heat)3. May change color or size
Term
 Show how H2O changes when heated or cooled.
Definition
Term
 What is a BTU?
Definition
 Amount of heat necessary to raise 1 # of H20 1 deg F
Term
 How does a BTU differ from Heat Intensity?
Definition
 Heat intensity is the temperature of the substance and is measured in degrees while the BTU is the amount of heat.
Term
 Define Specific Heat of a substance
Definition
 Amount of energy per unit of mass required to raise the temperature by 1 deg C
Term
 Formula for Quantity of Heat
Definition
 BTU = Weight (lbs) x Specific Heat X Temperature Difference
Term
 Define Heat Transfer
Definition
 Transfer of heat from one place to another
Term
 Define Conduction
Definition
 transfer of heat from molecule to molecule
Term
 Define Convection
Definition
 transfer of heat through a medium
Term
Definition
 transfer of heat by rays
Term
 What's Natural Convection?
Definition
 Heat transferred through a fluid medium, such as air or water, by currents that result from the rising of less dense, warm fluid and the sinking of heavier, cooler fluid.
Term
 What's Forced Convection?
Definition
 Heat transferred through a medium such as air or water by currents caused by a device powered by an external energy source.
Term
 What are the factors that effect heat transfer?
Definition
 Temperature, area of the coil, depth of the coil, and water flow rates
Term
 Define Thermodynamics
Definition
 Study of heat transfer, how to measure heat transfer, and how temperature affects the operation of everything inside and outside the HVAC/R system
Term
 As a substance is heated the molecules _______.
Definition
 Move faster
Term
 Heat exists in all substances down to a temperature of ______.
Definition
 -463 deg F
Term
 Heat energy can not be ____.
Definition
 destroyed
Term
 The human body gives off heat by ______.
Definition
Term
 How many Btu's are required to change 1 # of ice at 20 deg F to steam at 220 deg F?
Definition
 1,304 Btu
Term
 How many Btu's must be removed from 1 # of H20 at 200 deg F for it to end up as ice at 30 deg F?
Definition
 313 Btu
Term
 The temperature on the Fahrenheit scale where all molecular biology activity stops is ____.
Definition
 -460 deg F
Term
 True or False: When water boils at 212 deg F, it's only absorbing latent heat.
Definition
 True
Term
 True or False: Both sensible heat and latent heat transfers can be read by a thermometer.
Definition
 False, only sensible heat can be measured.
Term
 True or False: Water at 0 deg F has no heat energy or molecular activity.
Definition
 False, activity stops at absolute zero
Term
 True or False: Temperature difference doesn't affect heat transfer rate.
Definition
 False, temperature difference is the main factor
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