Types of Heat
Heat that changes temperature but not state
Sensible Heat
Temperature where liquid and vapor coexist
Saturation Temperature
Where refrigerant absorbs heat
Evaporator
Component that increases pressure
Compressor
Low suction pressure indicates
Low charge or low load
What happens when pressure increases?
Saturation temperature increases
What happens when pressure increases?
Saturation temperature increases
Where refrigerant rejects heat
Condenser
Meters refrigerant flow
Expansion device
High superheat indicates
Starved evaporator
When boiling water stays at the same temperature while heating
What is latent heat?
Why refrigerant boils at low temperatures in an evaporator
Because pressure is low
The state of refrigerant leaving the evaporator
Superheated vapor
Component responsible for heat rejection
What is the condenser?
High head pressure could be caused by
Overcharge or poor airflow
The type of heat responsible for comfort in a room temperature change
What is sensible heat?
What condition must exist for phase change to occur
Saturation
The state of refrigerant entering the metering device
Subcooled liquid
Component where phase change absorbs heat
What is the evaporator?
No temperature change while heat is added
Latent heat process
The moment when the “next BTU” causes a phase change
What is latent heat at saturation?
A system where pressure rises but temperature does not—what is happening?
Approaching or at phase change conditions
What actually moves heat through the system
Refrigerant
Component most affected by airflow issues
What is the evaporator?
Evaporator not absorbing heat—likely issues
Airflow problem or low refrigerant