Which of the following statements regarding gas furnace systems is/are true?

a. A low-efficiency gas furnace system generally operates at a higher AFUE steady-state and a lower seasonal efficiency rating.

b. Technological upgrades have improved gas furnace systems so dramatically such that the secondary heat exchanger extracts and recovers 100 % of the heat.

c. A chimney is required in all the three types of gas furnace to vent the flue gases.

d. The least to most efficient gas furnace systems, in that order, are the natural draft, induced draft, and condensing systems.

1. B and C only

2. A and D only

3. B only

4. D only

Answer rating: 100% (QA)

Option B only b Technological upgrades have improved gas furnace systems ... View the full answer