HVAC Quizzes: Exam 2 Flashcards
What are the minimum and max air velocities and what will they cause if they are above or below the minimum requirements?
Between 20 to 65 FPM
- less than 20 you get stratification
- more than 65 you get drift
List four types of propeller fans;
- ___ disk
- ____ wheel (axial flow)
- ____ axial (spiral discharge)
- ____ axial (laminar discharge)
- fan disk
- fan wheel
- tube axial
- vane axial
What does laminar mean?
straight flow
List four types of impeller or centrifugal fans?
- backward inclined
- air foil
- backward curved
- forward curved
- radial
- fan wheel
List various components of an HVAC system that causes resistance to air flow? (5)
- filter
- coil
- elbows
- supply duct
- return duct
What is the formula to calculate air flow?
CFM = duct area x velocity
What is the formula to calculate velocity?
V (in ft per min) = 4005 x VP(sqrt) and in inches wg
List two air conditioning applications?
- equipment cooling
2. comfort cooling
List four types of HVAC systems
- all air
- air-hydronic
- all hydronic
- unitary
What do we control in an air conditioning system?
- temperature (heat/cool)
- air cleanliness
- humidity control (dehumidification/humid)
- air movement
List various components of an AC system;
- central air handler
- supply ductwork
- supply air distribution device (diffuser)
- return air grille
- outdoor air
- return ductwork
- refrigeration equipment
- water/ref piping
List the influences that may affect individual comfort in a Hvac system?
- exposure
- floors
- room layouts
- use
- lighting
- life safety
- comfort
- draft
List three types of zone control systems;
- constant volume (CV)
- Variable air volume (VAV)
- Variable volume and temp
