Heat Transfer
The most basic heat gain and heat loss calculations are based on the ___ of the space being conditioned.
area
Air leaving the evaporator is typically ___° cooler than the air entering.
17-20
AHRI rates condensers with air passing over them at ___°F.
95
A trap in the condensate line prevents ___.
air from being drawn up into unit?
Comfort is a balance of temperature, humidity, air movement, and ___.
What is air cleanliness?
As the ___ increases, the rate of heat transfer will increase
What is temperature differential?
A service valve is used to ___.
What is isolate refrigerant for servicing?
A normal evaporator boiling point under typical conditions is ___.
40
Pressure in a duct system is measured in ___
What is inches of water column (in. WC)?
The dry-bulb temperature is a measure of ___.
What is sensible heat level of air?
One commonly used characteristic of building materials is the ___-value.
R
A typical superheat reading at the evaporator outlet on a 95°F day is ___.
10-12
A high-efficiency AC system operates with a boiling point of __
45
True or false: The blower provides the pressure difference needed to move air through the duct system.
true
Dew point is the temperature at which ___.
What is moisture condenses from air?
True or False: Very little heat is lost through the roof.
false
The liquid line temperature helps determine ___.
What is subcooling?
True or False: Bigger is always better when sizing HVAC equipment.
false
Reason for using an extended plenum system?
What is to prolong plenum closer to last register?
True or False: Heat produced in the body equals heat lost = comfort
TRUE
The solar load on a structure comes from ___.
What is radiation from the sun?
Instrument used to check a short in a compressor motor winding?
hat is an ohmmeter?
SEER is considered a more accurate rating system than ___.
EER
True or False: Return ducts never need to be insulated.
What is False?
The density of air is defined as ___.
What is weight per cubic foot?