Author Question: Explain why furnace efficiencies jump from 80 to 90 What will be an ideal ... (Read 53 times)

lbcchick · **on:** Jul 26, 2018

Explain why furnace efficiencies jump from 80 to 90

What will be an ideal response?

Question 2

Why are tubing brushes used?

What will be an ideal response?

carlsona147 · **Reply #1 on:** Jul 26, 2018

Answer to Question 1

Efficiencies above 80 cause condensation either in the furnace or in the vent. The flue gas for efficiencies below 90 is too hot for PVC vent. So the vent on a furnace between 80 and 90 must withstand high temperature and water, making it impractical.

Answer to Question 2

To clean oxides, oil, or dirt off of copper tubing so it can be soldered or brazed.