Pneumatic control systems A) are the most recent type of ...

[Sufayan.ah]

Pneumatic control systems
 
  A) are the most recent type of commercial control B) Use air pressure to modulate control valves
  C) Have no moving parts D) Use electric motors to modulate control valves

Question 2

The primary control for all HVACR functions in a direct digital control (DDC) system is
 
  A) Not necessary. DDC systems do not use primary controllers
  B) A computer
  C) A multistage thermostat
  D) A relay pack

[AISCAMPING]

Answer to Question 1

B

Answer to Question 2

B

[Sufayan.ah]

Gracias!

[isabelt_18]

Thanks for the timely response, appreciate it