HERS Diagnostic and Field Testing Questions and Answers

Question 1

A HERS Rater performs a blower door test on a new construction home and obtains a result of 6.5 ACH50.
The applicable energy code for the jurisdiction requires a maximum of 5.0 ACH50.
While the blower door is still running, which of the following is the most effective and direct method for the rater to identify the largest air leakage pathways?

Accepted Answer

Systematically feeling for drafts by hand at common leakage points like sill plates and window frames.

Answer

Using an infrared camera to scan the interior surfaces of the thermal envelope.

Answer

Conducting zonal pressure diagnostics by measuring pressure differences between rooms.

Answer

Releasing theatrical smoke outside the building and observing where it is drawn in.

Question 2

During a duct leakage test on a system located entirely within the conditioned space, a rater can perform either a 'total duct leakage' test or a 'leakage to outside' test. According to RESNET standards, which test result can be used for compliance if the goal is to meet a 'leakage to outside' requirement?

Accepted Answer

The 'total duct leakage' test result can be used, as it will always be greater than or equal to the leakage to the outside.

Answer

Only the 'leakage to outside' test result is acceptable.

Answer

Neither test is appropriate; a visual inspection is required instead.

Answer

The two test results must be averaged to determine compliance.

Question 3

A rater is preparing to conduct a worst-case depressurization test in a Combustion Appliance Zone (CAZ) containing a natural draft water heater and a furnace. Which of the following is a critical first step in the standard procedure?

Accepted Answer

Establish and record the baseline pressure of the CAZ with reference to the outdoors before turning on any fans or appliances.

Answer

Immediately fire the largest combustion appliance to warm the flue.

Answer

Turn on all exhaust fans and the furnace air handler simultaneously.

Answer

Pressurize the house to +50 Pa with a blower door to identify any pre-existing backdrafting.

Question 4

A HERS Rater is using an infrared camera to inspect a wall cavity on a cold day. The camera shows a distinct, cool, feathery pattern on the interior drywall surface. This pattern most likely indicates:

Accepted Answer

A void or gap in the insulation allowing for air leakage and convection.

Answer

The normal location of wood framing members conducting heat to the outside.

Answer

Surface moisture or condensation due to a high interior relative humidity.

Answer

A thermal bridge caused by a steel structural component.

Question 5

When performing a zonal pressure diagnostic test with a blower door running, a rater measures the pressure difference between an attached garage and the main house. The reading is -45 Pa (Pascals). What does this reading indicate?

Accepted Answer

The air barrier between the house and the garage is very effective (tight).

Answer

The HVAC system is severely unbalanced between the house and the garage.

Answer

The garage is well-sealed from the outdoors but has a very leaky connection to the house.

Answer

A large amount of duct leakage is occurring within the garage.

Question 6

Which of the following conditions must be met for a rater to safely proceed with measuring the Carbon Monoxide (CO) levels in the flue gas of a combustion appliance during a CAZ test?

Accepted Answer

The ambient CO level in the CAZ must remain below 35 ppm.

Answer

The flame must be blue with consistent orange tips.

Answer

The appliance must demonstrate spillage for at least 60 seconds to ensure a proper sample can be taken.

Answer

The flue draft pressure must be positive, indicating strong updraft.