Reflective foam core insulation, also known as radiant barrier insulation, is primarily designed to reflect radiant heat. It typically consists of a layer of foam or bubble wrap sandwiched between two layers of reflective foil. While reflective foam core insulation can be a valuable component of an overall insulation system, it is not typically used as the sole insulation material in a house. Here's why:
Heat transfer: Reflective foam core insulation primarily works by reflecting radiant heat. It is effective in reducing radiant heat gain during hot weather or in hot climates. However, it is less effective at reducing conductive and convective heat transfer, which are significant contributors to heat gain or loss. In colder climates or during cold seasons, conductive and convective heat transfer become more important, and reflective foam core insulation alone may not provide sufficient insulation.
Building codes: Building codes typically require a minimum level of insulation for residential buildings. These codes often specify minimum R-values (thermal resistance) for different regions and climate zones. Reflective foam core insulation alone may not meet these minimum requirements. R-value measures the insulation's resistance to conductive heat flow, and reflective insulation has a relatively low R-value compared to other types of insulation.
Moisture control: Insulation plays a crucial role in controlling moisture within the walls and preventing condensation. Reflective foam core insulation, by itself, does not provide effective moisture control. To ensure proper moisture management, additional insulation materials such as fiberglass, cellulose, or spray foam are typically used in conjunction with vapor barriers or other moisture control measures.
Structural integrity: Reflective foam core insulation is relatively lightweight and may not provide the necessary structural support for walls or roofs. Other insulation materials, such as rigid foam boards or spray foam, offer better structural stability and can help strengthen the building envelope.
In summary, while reflective foam core insulation can be a useful component in reducing radiant heat gain, it is generally not recommended as the sole insulation material in a house. It is more commonly used in combination with other insulation types to provide a comprehensive and effective insulation system that addresses all modes of heat transfer and meets building code requirements.