🔍 Key Concepts

• Air flow vs. pressure: How different fan types handle resistance in long duct runs • Axial vs. centrifugal fans: Basic differences in how they move air • Ducted systems: Why static pressure capability matters when air must travel through ducts, filters, and coils

💭 Think About

• Which fan type is best at overcoming higher static pressure in ductwork rather than just moving a lot of air in open spaces? • Among the listed fans, which ones are primarily axial-flow (moving air straight through) and which one changes the direction of the airflow? • Think about where you usually see propeller or tube-axial fans used versus fans in central HVAC or air-conditioning units that feed multiple rooms through ducts.

✅ Before You Answer

• Identify which option is a centrifugal (radial-flow) design and which are axial-flow designs • Consider which fan type is most common in building HVAC air handlers rather than in window units or exhaust fans • Ask: which design is specifically chosen for higher static pressure and quieter operation in ducted systems?