Poorly maintained humidifiers can become indoor air quality ...

[Sufayan.ah]

Poorly maintained humidifiers can become indoor air quality concerns because of:
 
  A) Mold and mildew growth.
  B) Unintended chemical reactions with HFC refrigerants.
  C) Increased static discharge around all electrical connections.
  D) Increased outgassing of volatile organic compounds.

Question 2

What is the difference between a a 90 percent furnace with a sealed combustion system and a typical 90 percent furnace?
 
  A) Sealed combustion units do not produce any combustion products.
  B) Sealed combustion units use household vented air for combustion.
  C) Sealed combustion units may use PVC pipe for venting material.
  D) Sealed combustion units require combustion air to be piped in from the outside.

[sultansheikh]

Answer to Question 1

A

Answer to Question 2

D

[Sufayan.ah]

YES! Correct, THANKS for helping me on my review

[daiying98]

Thanks for the timely response, appreciate it