“The Wood Products Council” is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request. Copyright Materials This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any This presentation is protected by US and material of construction or any method or manner of handling, using, International Copyright laws. Reproduction, distributing, or dealing in any material or product. distribution, display and use of the presentation without written permission of the speaker is Questions related to specific materials, methods, and services will prohibited. be addressed at the conclusion of this presentation. © The Wood Products Council 2012 Slide 2 of 35 Radiant Barrier Sheathing Radiant Barrier Sheathing LP Building Products 414 Union Street, Suite 2000 Nashville, TN 37219 Tony Pugel, Ph.D www. LPcorp.com Course Number: LPTS01 Senior Process Technologist Learning Units: 1.00 LP Building Products LP Building Products is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on Nashville TN completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available upon request. (615)598-3074 This program is registered with AIA/CES for continuing professional registration. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material or construction or any method or manner of handling, using, [email protected] distributing or dealing in any material or product. Questions related to specific materials, methods and services should be directed to the program instructor. This presentation is protected by US and International copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited. Slide 3 of 35 Learning Objectives – Radiant Barrier Sheathing Outline • Introduction At the end of this program, participants will: • Heat transfer • Radiant heat transfer 1. Understand forms of heat transfer • Radiant heat transfer in roofs and attics 2. Understand how radiant barriers affect heat transfer through roof systems • Radiant barrier types 3. Understand the benefits of a radiant barrier • Radiant Barrier Sheathing sheathing in both a heating and cooling • Other considerations environment • Case Studies 4. Understand radiant barrier sheathing applications • Building Codes and Energy Programs and their function, as well as key installation • Selection and Installation of Radiant Barrier Sheathing methods • Summary • References Introduction Outline • 1860 – French scientist Peclet investigated the • Introduction insulating effect of metals in reducing radiant • Heat transfer heat transfer • Radiant heat transfer Visual reflectance or color are not the determining factors • Radiant heat transfer in roofs and attics • Radiant barrier types • 1925 – First patents on reflective surfaces for • Radiant Barrier Sheathing building insulation Radiant barrier and reflective insulation • Other considerations introduced for commercialization • Case Studies • Building Codes and Energy Programs • 1960s – NASA developed thin, metalized films for Apollo space program • Selection and Installation of Radiant Barrier Sheathing Radiant barrier inducted into the Space • Summary Technology Hall of Fame • References Heat Transfer Roof/Attic Examples of Heat Transfer • Conduction – Heat transfer between adjacent solids, liquids, or gases due to • Radiation temperature differences The roofing materials are radiantly heated from the sun • Convection • Conduction – the transfer of heat from one place The roofing materials conduct to another by the movement of heat from the exterior to the fluids interior surfaces • Convection • Radiation The interior surface heats the attic – The transfer of heat through air causing hot air to rise and electromagnetic waves traveling exhaust through ridge or gable through a vacuums or an air space vents Slide 9 of 35 Slide 10 of 35 Outline Important Concepts of Radiant Heat Transfer • Introduction • Heat transfer • Radiant heat transfer • Radiant heat transfer in roofs and attics Solar Radiation • Radiant barrier types • Radiant Barrier Sheathing • Other considerations • Case Studies Reflectivity • Building Codes and Energy Programs • Selection and Installation of Radiant Barrier Sheathing • Summary Emissivity + Reflectivity = 1 Emissivity • References Slide 12 of 35 Radiant Barrier Properties Radiant Heat Gain • Radiant barriers are • In summer, heat absorbed defined to have an by roof components is emissivity of 0.1 or transferred by infrared less radiation to the attic floor • To work effectively, • Studies show an average low emissivity of 93% of solar radiated surfaces must face heat enters a building an air space through the attic Slide 13 of 35 Outline Radiant Heat Gain in the Attic • Introduction • Attic heat gain is primarily governed by solar radiation in • Heat transfer summer, and more by conduction/convection from the • Radiant heat transfer living space in winter. • Radiant heat transfer in roofs and attics • Radiant barrier types • Airflow does not move radiant energy, so increasing ventilation rate will not replace the efficiency gained by • Radiant Barrier Sheathing use of a radiant barrier. • Other considerations – Ventilation is still important for conduction and convection heat • Case Studies transfer in the attic/roof. • Building Codes and Energy Programs • Selection and Installation of Radiant Barrier Sheathing • Summary • References Slide 16 of 35 Summer Radiant Heat Gain Residential Energy Usage (EIA 2013 est.) • Summer roof sheathing temperatures can reach 160°F with attic Other, 15.5% Furnace/Boiler, 2.1% temperatures exceeding Computers, 2.1% 120°F TV, 4.8% Dishwasher, 1.5% Heating/Cooling, 38.5% • Radiant barrier roof Washer, 0.5% Lighting, 8% sheathing blocks up to 97% of the radiant heat from being transmitted Freezer, 1.2% into the attic Dryer, 3.3% Water Heating, Cooking, 2.8% 14.1% Refrigeration, 5.6% Slide 17 of 35 How radiant barrier sheathing reduces energy costs Outline • Introduction Apply Radiant Cooling Scenario • Heat transfer Barrier • Radiant heat transfer • Radiant barrier reduces heat movement from the roofing • Radiant heat transfer in roofs and attics 1 material to the attic space • Radiant barrier types • Radiant Barrier Sheathing • The attic space air temperature is reduced and heat • Other considerations 2 radiated from the roof to attic floor is reduced • Case Studies • Heat transfer from the attic floor to the living space is • Building Codes and Energy Programs reduced 3 • Ducting and air handling equipment in the attic are cooler • Selection and Installation of Radiant Barrier Sheathing • Summary Reduced energy costs • References Roof Sheathing Radiant Barrier Types R R a a Radiant Barrier f f foil/film may be Installations t t e e placed in a of Radiant 1. Foil, bubble insulation, or t r number of Attic Space locations in the Barrier Types metalized films usually made J J O O attic I Insulation I S S in Attics with aluminum t t Living Space 2. Radiant barrier sheathing - Radiant Barrier Sheathing Radiant Barrier R R structural sheathing (OSB or a a Sheathing is f f placed with the plywood) with foil overlay t t e e foil facing the r r attic space Attic Space 3. Interior radiation control coatings – “ radiation barrier Roof Sheathing R R Interior Radiation paint” a a Control Coatings f f t t are sprayed onto e e the underside of r r the roof sheathing Attic Space Horizontal and Rafter Mounted Radiant Barriers Outline • Introduction • If interior attic gable walls are covered with the radiant barrier, roof-deck and rafter-mounted radiant barriers • Heat transfer provide equivalent ceiling heat gain reductions to • Radiant heat transfer horizontal installations • Radiant heat transfer in roofs and attics • Radiant barrier types • Horizontal application of a radiant barrieron the attic • Radiant Barrier Sheathing floor is more likely to accumulate dust which increases the emissivity of the surface • Other considerations • Case Studies • The main feature of the rafter mounted radiant barrier • Building Codes and Energy Programs is the reduction of radiant heat flow into the attic space • Selection and Installation of Radiant Barrier Sheathing – Especially important for air conditioning and ductwork • Summary • References Radiant Barrier Sheathing Outline • Introduction • Heat transfer • Radiant heat transfer • Radiant heat transfer in roofs and attics • Radiant barrier types • Radiant Barrier Sheathing • Other considerations OSB Sheathing Standard OSB roof sheathing (PS-2 Exposure 1) • Case Studies • Building Codes and Energy Programs Maintains bond of foil to OSB during Adhesive the lifetime of the sheathing • Selection and Installation of Radiant Barrier Sheathing Aluminum Foil ~0.0025” thickness foil with • Summary adhesive and kraft paper backing • References Radiant Barriers and Shingles Other Considerations with Radiant Barrier Sheathing • Concern that heat would melt or degrade composite • Cell Phone Reception shingles – As with other metal building components,