Author Question: The four categories of gas-fired furnaces are based on: A) Efficiency. B) Flue gas temperature ... (Read 54 times)

jon_i · **on:** Jul 24, 2018

The four categories of gas-fired furnaces are based on:

A) Efficiency. B) Flue gas temperature and pressure.
C) Firing rate. D) Category of gas being burned.

Question 2

What is the advantage of using multiple compressors on a supermarket rack system?

A) System capacity can match refrigeration loads, which vary over a wide range.
B) Extra compressors provide backup in case one quits working.
C) Using multiple parallel compressors makes the use of multiple refrigerants possible.
D) The compressors can operate at a higher compression ratio as a parallel group.