Dust buildup reduces reflectivity
The attic floor application of radiant barrier is most susceptible to accumulation of dust, while downward facing reflective surfaces used with many roof applications are not likely to become dusty. In time, a dusty attic floor application will lose much of its effectiveness: predictive testing suggests by nearly half within ten years.
Potential for moisture condensation
Condensation can be a concern when a radiant barrier is installed on the attic floor directly on top of batt, rolled or blown insulation. During cold weather, water vapor from the interior of a house may move into the attic. In most cases, this water vapor will not cause problems because attic ventilation will carry excess vapor away. But, during cold weather, a radiant barrier on top of the insulation could cause water vapor to condense and even freeze on the barrier's underside. Therefore, a radiant barrier used in the attic floor application must allow water vapor to pass through it.
Attic space is often needed for storage
The floor location is not appropriate for radiant barrier when the attic is used for storage, since the surface must be exposed to the attic space. Also, kitchen and bathroom vents and recessed lights should not be covered with the radiant barrier. If one-sided radiant barrier foil is laid on top of the insulation with the reflective side facing down and touching the insulation, the radiant barrier will lose most of its effectiveness in reducing heating and cooling costs.
Finally, many older homes in southern states, like Texas, Arizona and Alabama, have HVAC units located in the attic. If a radiant barrier is installed on the attic floor the attic space will still get hot in the summer months. The hotter the attic, the harder your air conditioning unit will have to work to cool your home.
View the best ways to install Enerflex Radiant Barrier in an attic.
See installation video.
The attic floor application of radiant barrier is most susceptible to accumulation of dust, while downward facing reflective surfaces used with many roof applications are not likely to become dusty. In time, a dusty attic floor application will lose much of its effectiveness: predictive testing suggests by nearly half within ten years.
Potential for moisture condensation
Condensation can be a concern when a radiant barrier is installed on the attic floor directly on top of batt, rolled or blown insulation. During cold weather, water vapor from the interior of a house may move into the attic. In most cases, this water vapor will not cause problems because attic ventilation will carry excess vapor away. But, during cold weather, a radiant barrier on top of the insulation could cause water vapor to condense and even freeze on the barrier's underside. Therefore, a radiant barrier used in the attic floor application must allow water vapor to pass through it.
Attic space is often needed for storage
The floor location is not appropriate for radiant barrier when the attic is used for storage, since the surface must be exposed to the attic space. Also, kitchen and bathroom vents and recessed lights should not be covered with the radiant barrier. If one-sided radiant barrier foil is laid on top of the insulation with the reflective side facing down and touching the insulation, the radiant barrier will lose most of its effectiveness in reducing heating and cooling costs.
Finally, many older homes in southern states, like Texas, Arizona and Alabama, have HVAC units located in the attic. If a radiant barrier is installed on the attic floor the attic space will still get hot in the summer months. The hotter the attic, the harder your air conditioning unit will have to work to cool your home.
View the best ways to install Enerflex Radiant Barrier in an attic.
See installation video.
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