What advantage is there to maintaining a negative pressure on the ...

[123654777]

What advantage is there to maintaining a negative pressure on the heat exchanger?
 
  A) The vent will not work unless the heat exchanger is at a negative pressure.
  B) The negative pressure helps draw in return air from the house, increasing efficiency.
  C) Safety; it ensures combustion products do not leak out into the air stream.
  D) Combustion air can only be drawn into the oil burner if a negative pressure is maintained.

Question 2

How does soot accumulation on the inside of the heat exchanger affect system efficiency?
 
  A) The soot acts like an insulator on the inside of the heat exchanger, thereby reducing efficiency.
  B) The soot provides extra fuel during the high-fire stage, thereby increasing efficiency.
  C) The soot increases the heat exchanger internal resistance, thereby increasing efficiency.
  D) The soot acts like an insulator on the inside of the heat exchanger, thereby increasing efficiency.

[lkanara2]

Answer to Question 1

C

Answer to Question 2

A

[123654777]

Excellent

[sarah_brady415]

TYSM