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3. Plans shall indicate insulation type, thickness, and location; ventilation opening types, <br />sizes and locations; radiant barrier location; and roof surface type as appropriate, <br />depending on the option selected from Subsection 1. <br />4. For compliance with Subsection 1.3, additional ventilation of the space containing a <br />radiant barrier shall be provided by at least one of the following: <br />4.1. A baffled ridge vent installed in accordance with the manufacturer's <br />instructions in addition to lower inlet openings to provide a total of no less than <br />one square foot of net free vent area for each 300 square feet of roof area. No less <br />than 30 percent of the total vent area shall be in either the ridge vent or the lower <br />half of the ventilated space. <br />4.2. Asolar-powered exhaust fan that provides at least one cubic foot per minute <br />of airflow for each square foot of roof area. <br />4.3. Upper and lower vents with total net free vent area of at least one square foot <br />for each 150 square feet of roof area. At least 30 percent of the total vent area shall <br />be in the upper half of the ventilated space and at least 30 percent of the total vent <br />area shall be in the lower half of the ventilated space. <br />5. For compliance with Subsections 1.3 or 1.4, a radiant barrier shall have an emissivity of <br />no greater than 0.05 as tested in accordance with ASTM E-408. The radiant barrier shall <br />be installed with the shiny side facing dawn and with a minimum air gap thickness of/a <br />inch below. The radiant barrier may be securely attached to the roof framing or may be <br />laminated to the bottom of the roof sheathing. <br />A radiant barrier is a sheet of material with a low emissivity on at least one side that is <br />used to reduce radiant heat transfer. Radiant barriers typically have a shiny metallic <br />appearance. <br />6. For compliance with Subsection 1.4, a cool roof shall have an infrared emittance of no <br />more than 0.75 when tested in accordance with ASTM E-408 and a high solar reflectance. <br />The manufacturer's test results shall be acceptable for compliance. A cool roof has both a <br />light color (high solar reflectance) and a high emittance (can reject heat back to the <br />environment). White painted surfaces and other smooth white coatings typically meet <br />these requirements. Surfaces that do not meet the requirements include unpainted metal <br />and metalized roof coatings (silver appearance). <br />7. At building sites higher than a 2,400-foot elevation, only Subsections 1.1 or 1.2 shall be <br />acceptable for compliance. <br />8. For purposes of compliance with Subsection 1.5, the Roof Heat Gain Factor (RHGF) <br />shall be calculated as described in Equation 8-1. <br />Equation 8-1 <br />RHGF=U,XaxRB <br />Where: <br />RHGF =Roof Heat Gain Factor [Btu/ftZ-h-°F] <br />U, =overall thermal transmittance value for the gross area of opaque roof surfaces <br />[Btu/ft~-h--°F] <br />a =roof surface absorptivity. Between 0.3 and 1.0 [unitless] <br />RB =Radiant Barrier credit. Equals 0.33 if a radiant barrier is installed and 1.00 <br />otherwise [unitless]. Radiant barrier installation must comply with subsection 8.1 <br />to qualify for Radiant Barrier credit. <br />4 <br />