HERS Blower Door & Duct Testing 2

Question 1

During a blower door test, what effect does a large open fireplace damper have on the result?

Accepted Answer

It increases the measured CFM50, making the house appear leakier

Answer

It has no measurable effect

Answer

It decreases the measured CFM50 by creating a backdraft

Answer

It causes the fan to stall

Question 2

What is the primary reason HERS raters must depressurize ducts to a specific pressure (typically 25 Pa) during a duct leakage test?

Accepted Answer

To standardize results so tests from different homes and raters are comparable

Answer

To replicate worst-case wind conditions

Answer

To maximize airflow through the ducts

Answer

To satisfy fire code requirements

Question 3

In a duct leakage test, CFM25 total is measured at 300 cfm and CFM25 out is measured at 180 cfm. What is the duct leakage to outside?

Accepted Answer

120 cfm

Answer

480 cfm

Answer

300 cfm

Answer

180 cfm

Question 4

Which condition must be established before starting a blower door test according to RESNET standards?

Accepted Answer

All interior doors must be open

Answer

The HVAC system must be running at full capacity

Answer

Combustion appliances must be turned off and flues sealed

Answer

Windows must be left partially open for pressure relief

Question 5

What does a high ELA (Effective Leakage Area) value indicate about a home?

Accepted Answer

The home has a large equivalent hole size and poor air sealing

Answer

The home has excellent air sealing

Answer

The HVAC system is oversized

Answer

The windows are energy efficient

Question 6

During duct leakage testing, why is it important to seal all supply and return grilles before testing?

Accepted Answer

To isolate duct leakage from building envelope leakage

Answer

To prevent dust from entering the duct system

Answer

To increase duct pressure above 25 Pa

Answer

To comply with OSHA confined space rules

Question 7

A home tests at 6 ACH50. Which HERS reference home air leakage rate would this most closely correspond to for a typical new construction standard?

Accepted Answer

It exceeds the typical new construction benchmark of 3 ACH50

Answer

It meets the ENERGY STAR requirement of 7 ACH50

Answer

It is at the Passive House standard of 0.6 ACH50

Answer

It equals the IECC 2021 mandatory maximum