Abbreviations
What does HVAC stand for?
Heating, Ventilation, and Air Conditioning
What color is the load wire?
Black
How often should you clean your ac unit?
Every 4 weeks
What's the thermostat used for?
monitors and regulates temperature by switching heating or cooling equipment on and off to maintain a desired set point
What does a screw driver look like?
Up to teacher
What does DMM stand for?
Digital MultiMeter
What color is the ground wire?
Green or Bare Copper
Why does duct work need an X-shaped bend in it?
To improve airflow and increase structural support
Whats the order of operations?
the thermostat calls for heat, the inducer motor starts, the pressure switch closes, the igniter glows, the gas valve opens, the flame is proven, the main blower starts, and finally, the system shuts down after the heat requirement is met
What is the difference between an impact and a drill?
An impact has more torque
What does BTU stand for?
British Thermal Units
What is the symbol for Resistance?
Ω
What are 3 safeties in a gas furnace?
high limit switch, flame rollout switch, pressure switches, flame sensor, door switch, and induced draft motor
What is thermodynamics?
the branch of physics and chemistry that studies the relationships between heat, work, temperature, and energy
What is the actual name for Dikes?
Pliers
What does TXV stand for?
Thermostatic Expansion Valve
What is Ohms law?
V=IxR
I=V/R
R=V/I
What's the difference between hermetic and semi hermetic?
hermetic compressors are fully welded, sealed units that cannot be repaired, while semi-hermetic compressors use bolted housings, allowing for field repairs, motor replacements, and maintenance
What is a heat exchanger?
a device that efficiently transfers thermal energy (heat) between two or more fluids—liquids or gases—without mixing them
Up to teacher
What does FLA stand for?
Full Load Amperage
Whats the different between a series circuit and a parallel circuit?
Series circuits have a single path for current, where as parallel circuits have multiple branches, providing separate paths for current to flow.
What's the most common refrigerant?
R-22 (Freon)
How do you see if an oil furnace is running?
listen for the hum of the motor, feel for warm air from registers, and check for a steady, quiet roar rather than banging or silence
What is the most common tool used inside the HVAC field?
DMM