1. Name the five changes that are made in air to condition it.

 a.
 b.
 c.
 d.
 e.

2. Name the two ways that a structure obtains fresh air.

 a.
 b.

3. Name the two type of blowers that move the air in a forced-air system.
 
 a.
 b.

4. Which type of blower is used to move large amounts of air against low pressures?
 

5. Which type of blower is used to move large amounts of air in duct work?
 

6. Name two reasons why duct work resists airflow.

 a.
 b.

7. Name four types of duct distribution systems.

 a.
 b.
 c.
 d.

8. Name two types of blower drives.

 a.
 b.

9. What is the pressure in ductwork expressed in?
 

10. What is a common instrument used to measure pressure in duct work?
 

11. Why is pounds per square inch not used to measure the pressure I duct work?
 

12. Name the three types of pressures created in moving air in duct work.

 a.
 b.
 c.
 

13. Name two types of return air systems.

 a.
 b.

14. What component distributes the air in the conditioned space?
 

15. Where is the best place to distribute warm air?
 

16. Where is the best place to distribute cold air? Why?
 

17. What chart is used to size duct work?
 

18. Name four materials used to manufacture duct.

 a.
 b.
 c.
 d.

19. What fitting leaves the trunk duct and directs the air into the branch duct?
 

20. The duct sizing chart is expressed in round duct. How can this be converted to square or rectangular duct?
 

21. A fan delivers 6000 cfm against a total resistance of 2 inch WG, what is the estimated horse power?

 a.  Theoretical
 b.  Assuming a 62.8% efficiency

22. 9800 cfm of air is to be delivered through a duct. The maximum velocity is not to exceed 1400 fmp. The total equivalent length of the duct is 230 ft. Find:

a.  The required diameter of the duct.
 b.  The pressure loss for 100 ft.
 c.  The total friction loss in the duct.