Which option would produce the greatest increase in insulation value when re-siding with aluminum?

Which option would produce the greatest increase in insulation value when re-siding with aluminum?

• A. Perforated reflector foil
• B. Fiberglass batt
• C. Foam board
• D. Cellulose

Answer: (A)

Radiant heat transfer is a big part of how heat moves through aluminum siding, so the most effective way to boost the assembly’s insulation value is to cut down on radiant heat entering the wall. Perforated reflector foil placed with an air gap behind the siding acts as a radiant barrier, reflecting infrared energy back toward the exterior. That reflection can substantially reduce the amount of heat that makes it into the wall cavity, especially in sunny, hot conditions. The perforations help keep moisture moving so that condensation isn’t trapped, which makes the installation more durable. Fiberglass batt, cellulose, and foam board all contribute by adding bulk insulation and lowering heat transfer through conduction, but they don’t block radiant heat as effectively as a reflective barrier does in this siding setup. Foam board can provide high R-value per inch, but the advantage of a radiant barrier behind aluminum siding, particularly when an air gap exists, is often greater for reducing heat gain with relatively little thickness.

Radiant heat transfer is a big part of how heat moves through aluminum siding, so the most effective way to boost the assembly’s insulation value is to cut down on radiant heat entering the wall. Perforated reflector foil placed with an air gap behind the siding acts as a radiant barrier, reflecting infrared energy back toward the exterior. That reflection can substantially reduce the amount of heat that makes it into the wall cavity, especially in sunny, hot conditions. The perforations help keep moisture moving so that condensation isn’t trapped, which makes the installation more durable.

Fiberglass batt, cellulose, and foam board all contribute by adding bulk insulation and lowering heat transfer through conduction, but they don’t block radiant heat as effectively as a reflective barrier does in this siding setup. Foam board can provide high R-value per inch, but the advantage of a radiant barrier behind aluminum siding, particularly when an air gap exists, is often greater for reducing heat gain with relatively little thickness.