The primary control for all HVACR functions in a direct digital ...

[nenivikky]

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 relay pack.
  D) A multistage thermostat.

Question 2

Soot accumulation on the heat exchanger is:
 
  A) Not possible with a gas furnace.
  B) A natural protective layer for the inside of the heat exchanger.
  C) Caused by incomplete combustion.
  D) Normal over a period of years.

[thall411]

Answer to Question 1

B

Answer to Question 2

C

[nenivikky]

Thanks for the timely response, appreciate it

[frankwu0507]

Excellent