Systems Flashcards
What is the equation for cooling tower approach?
T = T(water leaving) - Twb(air)
What is the typical range for indoor relative humidity in HVAC applications?
30% to 60%
What does SEER stand for in HVAC terminology?
Seasonal Energy Efficiency Ratio
True or False: The higher the SEER rating, the more efficient the HVAC system.
True
What is the function of a thermostat in an HVAC system?
To control the temperature by regulating the HVAC equipment
Fill in the blank: The _______ temperature is the temperature of the refrigerant entering the compressor.
Suction
What is the purpose of ductwork in an HVAC system?
To distribute conditioned air throughout a building
Multiple choice: Which of the following is NOT a type of HVAC system? A) Split system B) Packaged system C) Chilled beam system D) Electric fan
D) Electric fan
What does EER stand for?
Energy Efficiency Ratio
True or False: The latent heat load is associated with moisture removal from the air.
True
What is the main purpose of an air filter in an HVAC system?
To remove particulates and contaminants from the air
Fill in the blank: The _______ load is the heat gain or loss through walls, windows, and roofs.
Envelope
Multiple choice: Which component is responsible for compressing refrigerant in a cooling system? A) Evaporator B) Condenser C) Compressor D) Expansion valve
C) Compressor
True or False: A variable air volume (VAV) system adjusts airflow based on the heating and cooling needs of different zones.
True
What is the purpose of an expansion valve in a refrigeration cycle?
To reduce the pressure of the refrigerant before it enters the evaporator
Fill in the blank: The _______ temperature is the temperature of the refrigerant leaving the condenser.
Condensing
What is the primary function of a cooling tower?
To remove heat from water used in HVAC systems
Multiple choice: What is the main benefit of a geothermal heat pump? A) High operating costs B) Low energy efficiency C) Renewable energy source D) Limited applications
C) Renewable energy source
What does the term ‘approach temperature’ refer to?
The difference between the temperature of the cooling medium and the temperature of the fluid being cooled
What is the equation for cooling tower range
T(range) = T(CWR) - T(CWS)
If two pumps are placed in parallel the impact to the flow and pressure is?
Flow - doubled
Pressure - constant
What is the first pump / fan affinity law?
Fan / pump speed is directly proportional to flow rate.
* RPM1/RPM2 = CFM1/CFM2
* RP1/RPM2 = GPM1/GPM2
What is the pump / fan affinity law to determine head pressure?
Pressure = flow^2 (at constant speed)
* RPM1/RPM2 = sqrt(SP1/SP2)
What is the relationship of pump / fan energy to speed?
Horsepower (or kW) = volume or speed ratio cubed
* (HP1/HP2) = (RPM1/RPM2)^3
