BPI Building Analyst Field Exam Blower Door
Exam 2026/2027 | Verified Practice Questions
& Accurate Answers | Comprehensive Study
Guide
What is a Blower Door? - correct answer-- a diagnostic tool designed to measure
the airtightness of building and to help locate air leakage sites.
- the fan blows air into or out of the building to create a slight pressure difference
between inside and outside.
- this pressure difference forces air through all holes and penetrations in the
exterior envelope
- the tighter the building (eg. fewer holes), the less air you need from the blower
door fan to create a change in building pressure
- problem spots are easier to find using chemical smoke, an infrared camera or
simply feeling with your hand.
- it can also help you access the potential for backdrafting of natural draft
combustion appliances by exhaust fans and other mechanical devices
- help to determine the need for mechanical ventilation in the house
Basic dynamics of air leakage in buildings - correct answer-- for air leakage
(infiltration or exfiltration) to occur, there must be both a hole or crack, and a
driving force (pressure difference) to push the air through the hole.
Exam 2026/2027 | Verified Practice Questions
& Accurate Answers | Comprehensive Study
Guide
What is a Blower Door? - correct answer-- a diagnostic tool designed to measure
the airtightness of building and to help locate air leakage sites.
- the fan blows air into or out of the building to create a slight pressure difference
between inside and outside.
- this pressure difference forces air through all holes and penetrations in the
exterior envelope
- the tighter the building (eg. fewer holes), the less air you need from the blower
door fan to create a change in building pressure
- problem spots are easier to find using chemical smoke, an infrared camera or
simply feeling with your hand.
- it can also help you access the potential for backdrafting of natural draft
combustion appliances by exhaust fans and other mechanical devices
- help to determine the need for mechanical ventilation in the house
Basic dynamics of air leakage in buildings - correct answer-- for air leakage
(infiltration or exfiltration) to occur, there must be both a hole or crack, and a
driving force (pressure difference) to push the air through the hole.
