InterNACHI HVAC Systems Analysis 5

Question 1

Which condition is most commonly associated with a failed or dirty flame sensor in a gas furnace?

Accepted Answer

The furnace lights briefly then shuts off after a few seconds

Answer

A dirty or failed flame sensor cannot confirm ignition, causing the control board to shut off the gas valve within seconds as a safety measure.

Question 2

What is the primary purpose of a whole-house bypass humidifier bypass duct?

Accepted Answer

To route a portion of supply air through the humidifier pad and back to the return plenum

Answer

A bypass humidifier draws warm supply air through a water-saturated evaporative pad and returns the humidified air to the return plenum for distribution.

Question 3

A home inspector observes that a split-system AC compressor is located in a utility closet inside the home. What is the most significant concern?

Accepted Answer

The condenser coil cannot reject heat properly indoors, making the system ineffective

Answer

Air-cooled condensing units must be outdoors to reject heat to the atmosphere; placing one indoors prevents proper heat rejection and will cause the system to fail.

Question 4

Which HVAC filter rating system measures a filter's ability to capture particles of specific sizes?

Accepted Answer

MERV rating

Answer

MERV (Minimum Efficiency Reporting Value) rates filter efficiency from 1–16 based on the percentage of particles captured at different sizes.

Question 5

During an inspection of a packaged rooftop HVAC unit, what should the inspector note about the unit's curb?

Accepted Answer

Whether the curb is properly flashed and sealed to prevent roof leaks

Answer

Improper flashing or sealing around a rooftop unit curb is a leading cause of roof leaks and should be reported if deteriorated or improperly installed.

(InterNACHI) International Association of Certified Home Inspectors Practice Test

(InterNACHI) International Association of Certified Home Inspectors Practice Test

InterNACHI HVAC Systems Analysis 5