Tennessee Insulated Glass Unit
Fabrication Exam Practice Questions
And Correct Answers (Verified Answers)
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1. During the fabrication of insulated glass units (IGUs), which process is
primarily responsible for removing moisture from the sealed air space
to prevent condensation and fogging between panes over time?
A. Thermal tempering
B. Gas filling with argon
C. Spacer desiccant adsorption
D. Edge grinding
C. Spacer desiccant adsorption
The desiccant material inside the spacer absorbs moisture trapped
during assembly, preventing condensation within the sealed unit
throughout its service life.
2. In IGU fabrication, what is the primary function of the primary sealant,
typically polyisobutylene (PIB), applied to the spacer?
A. Provide structural strength
B. Act as a moisture vapor barrier
C. Improve thermal expansion
D. Enhance visual clarity
B. Act as a moisture vapor barrier
, The primary sealant prevents moisture infiltration into the unit by
forming a highly impermeable vapor barrier around the spacer.
3. Which gas is most commonly used to improve the thermal insulation
performance of insulated glass units?
A. Oxygen
B. Nitrogen
C. Argon
D. Helium
C. Argon
Argon is commonly used because it is denser than air, reducing
convective heat transfer within the sealed space.
4. What is the main purpose of the secondary sealant in IGU
construction?
A. Improve optical clarity
B. Provide structural integrity and durability
C. Act as a desiccant carrier
D. Reduce glass thickness
B. Provide structural integrity and durability
The secondary sealant, such as silicone or polysulfide, adds
mechanical strength and protects the primary seal from
environmental damage.
5. Which defect is most directly associated with seal failure in an
insulated glass unit?
A. Scratches on glass surface
B. Fogging between panes
C. Uneven thickness
D. Glass tint variation
B. Fogging between panes
Seal failure allows moisture to enter the air space, leading to
condensation or fogging between the glass panes.
6. In IGU fabrication, what is the purpose of edge deletion on low-
emissivity (Low-E) coated glass?
A. Improve coating reflectivity
B. Allow proper sealant adhesion
C. Increase UV resistance
, D. Enhance transparency
B. Allow proper sealant adhesion
Edge deletion removes the coating near the perimeter so sealants
can bond effectively to the glass surface.
7. Which spacer type is known for improved thermal performance due to
reduced conductivity?
A. Aluminum spacer
B. Steel spacer
C. Warm-edge spacer
D. Copper spacer
C. Warm-edge spacer
Warm-edge spacers reduce heat transfer at the edges, improving
overall thermal efficiency and reducing condensation risk.
8. What is the typical consequence of improper desiccant filling in the
spacer?
A. Increased glass strength
B. Reduced clarity
C. Moisture accumulation inside the unit
D. Enhanced insulation
C. Moisture accumulation inside the unit
Insufficient desiccant cannot absorb all trapped moisture, leading to
condensation inside the IGU.
9. Which quality control test evaluates the long-term durability of IGU
seals under environmental stress?
A. Impact resistance test
B. Accelerated weathering test
C. Optical distortion test
D. Thickness measurement
B. Accelerated weathering test
Accelerated weathering simulates temperature and humidity cycles
to assess seal durability over time.
10. What is the main purpose of gas filling in IGUs?
A. Increase weight
B. Improve acoustic performance only
C. Enhance thermal insulation
Fabrication Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationale 2026 Q&A| Instant
Download Pdf
1. During the fabrication of insulated glass units (IGUs), which process is
primarily responsible for removing moisture from the sealed air space
to prevent condensation and fogging between panes over time?
A. Thermal tempering
B. Gas filling with argon
C. Spacer desiccant adsorption
D. Edge grinding
C. Spacer desiccant adsorption
The desiccant material inside the spacer absorbs moisture trapped
during assembly, preventing condensation within the sealed unit
throughout its service life.
2. In IGU fabrication, what is the primary function of the primary sealant,
typically polyisobutylene (PIB), applied to the spacer?
A. Provide structural strength
B. Act as a moisture vapor barrier
C. Improve thermal expansion
D. Enhance visual clarity
B. Act as a moisture vapor barrier
, The primary sealant prevents moisture infiltration into the unit by
forming a highly impermeable vapor barrier around the spacer.
3. Which gas is most commonly used to improve the thermal insulation
performance of insulated glass units?
A. Oxygen
B. Nitrogen
C. Argon
D. Helium
C. Argon
Argon is commonly used because it is denser than air, reducing
convective heat transfer within the sealed space.
4. What is the main purpose of the secondary sealant in IGU
construction?
A. Improve optical clarity
B. Provide structural integrity and durability
C. Act as a desiccant carrier
D. Reduce glass thickness
B. Provide structural integrity and durability
The secondary sealant, such as silicone or polysulfide, adds
mechanical strength and protects the primary seal from
environmental damage.
5. Which defect is most directly associated with seal failure in an
insulated glass unit?
A. Scratches on glass surface
B. Fogging between panes
C. Uneven thickness
D. Glass tint variation
B. Fogging between panes
Seal failure allows moisture to enter the air space, leading to
condensation or fogging between the glass panes.
6. In IGU fabrication, what is the purpose of edge deletion on low-
emissivity (Low-E) coated glass?
A. Improve coating reflectivity
B. Allow proper sealant adhesion
C. Increase UV resistance
, D. Enhance transparency
B. Allow proper sealant adhesion
Edge deletion removes the coating near the perimeter so sealants
can bond effectively to the glass surface.
7. Which spacer type is known for improved thermal performance due to
reduced conductivity?
A. Aluminum spacer
B. Steel spacer
C. Warm-edge spacer
D. Copper spacer
C. Warm-edge spacer
Warm-edge spacers reduce heat transfer at the edges, improving
overall thermal efficiency and reducing condensation risk.
8. What is the typical consequence of improper desiccant filling in the
spacer?
A. Increased glass strength
B. Reduced clarity
C. Moisture accumulation inside the unit
D. Enhanced insulation
C. Moisture accumulation inside the unit
Insufficient desiccant cannot absorb all trapped moisture, leading to
condensation inside the IGU.
9. Which quality control test evaluates the long-term durability of IGU
seals under environmental stress?
A. Impact resistance test
B. Accelerated weathering test
C. Optical distortion test
D. Thickness measurement
B. Accelerated weathering test
Accelerated weathering simulates temperature and humidity cycles
to assess seal durability over time.
10. What is the main purpose of gas filling in IGUs?
A. Increase weight
B. Improve acoustic performance only
C. Enhance thermal insulation
