Radiant Heat Barrier Vs Attic Fan

This is really what drives heat flow the top surface temperature of the insulation.

Radiant heat barrier vs attic fan.

If you install a radiant barrier it will drop the surface temperatures inside the attic compared to the air temperature in the attic. Air temperatures would drop but surface temperatures would not drop much due to the radiant heat gain. However the fine print exists when the best available radiant barrier paint can only reflect about 75 of the radiant heat transfer. Meanwhile the radiant barrier foil will reflect 97 of the radiant heat transfer.

Radiant barrier should always be installed to work with the soffit and ridge. A radiant barrier works together with decent attic ventilation to drop both air temperature and surface temps. 95 of homeowners will not be able to install a roof mounted attic fan with temp switch or proper venting. When utilizing osb radiant barrier sheathing you can reflect up to 97 of solar radiation which translates into an attic heat reduction of up to 30 f.

For the record both the radiant barrier spray paint and the radiant barrier foil will reflect i e. Installing radiant barrier under the roof decking is the preferred method versus on top of the insulation because it gives an air gap for the heat to escape to the ridge vent without creating a potential moisture problem between the radiant barrier and the attic floor. A cooler attic space means less heat moving to the cooler space below the attic. Here is where many people screw up attic ventilation.

More is not always better. Keep in mind in order to get this price you must be very savvy with electrical and active venting solutions. Total diy radiant barrier installation costs w attic fan. Not emit radiant heat.