FC Energy Efficiency & System Optimization 3

Question 1

Which duct system characteristic most significantly reduces overall HVAC system efficiency?

Accepted Answer

Leaky ducts located in unconditioned spaces like attics or crawlspaces

Answer

Duct leakage in unconditioned spaces can reduce system efficiency by 20–30% because conditioned air is lost to areas outside the thermal envelope.

Question 2

A programmable thermostat contributes to energy savings primarily by:

Accepted Answer

Reducing heating demand when occupants are away or asleep

Answer

Programmable thermostats save energy by automatically lowering setpoints during unoccupied or sleeping hours, reducing heat loss over those periods.

Question 3

Zoning systems improve energy efficiency in a multi-story home by:

Accepted Answer

Delivering conditioned air only to occupied zones, reducing overall runtime

Answer

Zoning with motorized dampers directs heating only to occupied areas, preventing energy waste in unused rooms and reducing total system runtime.

Question 4

What effect does a dirty air filter have on furnace efficiency and performance?

Accepted Answer

Restricts airflow, increasing heat exchanger temperature and reducing efficiency

Answer

A clogged filter restricts airflow, causing the heat exchanger to overheat, the high-limit switch to trip, and overall system efficiency to drop significantly.

Question 5

The sensible heat ratio (SHR) is most relevant when evaluating a furnace's:

Accepted Answer

Interaction with a cooling coil in a combined HVAC system

Answer

SHR describes the proportion of sensible to total heat, which affects how a combined heating/cooling system handles both temperature and humidity.

(FC) Furnace Installation and Maintenance Certification Practice Test

(FC) Furnace Installation and Maintenance Certification Practice Test

FC Energy Efficiency & System Optimization 3