Red Seal Plumbing Practice Exam

Which of the following best describes a mid efficient furnace?

1. Uses a high-efficiency filter

2. Requires no electricity

3. Has a narrowed heat exchanger, added passages to slow the flue gas and has no draft hood

4. Is solar powered

The correct answer is: Has a narrowed heat exchanger, added passages to slow the flue gas and has no draft hood

A mid efficient furnace is designed to have an improved energy efficiency compared to a standard furnace, but is not as efficient as a high efficient furnace. This means that option A, which mentions the use of a high-efficiency filter, is incorrect because a high efficient filter is not a defining characteristic of a mid efficient furnace. Option B is also incorrect because although it is true that some mid efficient furnaces may require less electricity than a standard furnace, this is not a defining characteristic. Option D is also incorrect because the use of solar power is not a common feature of a mid efficient furnace. Option C is the best description as it outlines specific design features that differentiate a mid efficient furnace from a standard furnace.