StLouis Renewable Energy: Eco Conscious Roofs
Showing posts with label Eco Conscious Roofs. Show all posts
Showing posts with label Eco Conscious Roofs. Show all posts

StLouis White TPO Roof Project CAD Detail

StLouis, MO St. Louis, MO, USA Links to this post
CAD Detail No: 9821 White TPO Flat Roof Replacement Detail using Structodeck.

CAD Detail White Roof Install Masonry Building StLouis Investment Property
CAD Detail No: 9821 White TPO Flat Roof Replacement Detail using Structodeck
  • I've found that making a simple and quick graphic image to use as a visual tool to explain a building system repair to a client is easier when I provide a "non technical" image of the proposed work to be done.
  • Why GAF EverGuard® TPO
    • Outperforms standard TPO in heat aging and UV tests—the best predictors of TPO performance
      - Independent TPO Study proves EverGuard® TPO 60 mil Membrane is the best standard TPO in accelerated aging. View the key findings and full study here.
      - After accelerated heat aging at 275°F (135°C) for 112 days, EverGuard® TPO showed no cracking—while every one of the competitors’ samples had failed!
      - UV testing—Greater than 2.5 times the industry standard (ASTM D6878 weather resistance test)
    • Guarantees are available up to 25 years when using EverGuard® TPO 60 mil Membrane.*
    • Easier to install due to:
      - Large welding window
      - Most complete line of accessories
      - 10' (3.05 m) wide sheets



  • DESCRIPTION STRUCTODEK HD is not only an integral roofing system component; it also makes roofing easier with physical properties that generate structural rigidity and dimensional stability. The wood fiberboard composition of STRUCTODEK HD possesses natural bonding qualities, resulting in superior adhesion capabilities. Adhesive tightly grasps the fibers of STRUCTODEK HD without causing excess absorption, providing a solid and secure roof system which bonds very well with many asphalt, coal tar, and cold-process adhesive products. The lightweight nature of STRUCTODEK HD is better than heavier alternatives and will keep the roof load below the specified maximum weight. Source




  • Below photo prior jobsite building photo after barrel tile roof removal replaced with asphalt shingles.


    Kevin at Travis Roofing Supply was a great help in outlining the proper materials and needed prep to ensure the TPO roofing will meet and exceed the expectations of the Investment Property Owner plus the 25 year product guarranty. 

    Travis Roofing Supply is located just north of the Vandeventer/44 in the old RSG Roofing Building 


    Thank You for stopping by the Green Blog. If additional information in needed or you have a question let me know by posting a question or comment. Together we can make a difference and create a future that will benefit everyone.
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    Porch Roof Replacement

    StLouis, MO St Louis, MO 63109, USA Links to this post
    Photos and Project Descriptions of Roof Replacement on Front Porch of Investment Property in South St Louis MO
    • CertainTeed Ashphalt Shingles, Drip Edge, Lumber, and Misc Materials

    Porch Roof Replacement (6 Square Roof)
    Scotts Contracting-Porch Roof Replacement

    Used Clay Roofing Tiles For Sale

    StLouis, MO St Louis, MO 63109, USA Links to this post

    Clay Roofing Tiles - Recycled via Old World Roofing Company



    Clay Tiles from Porch of House

    170-Good Pcs

    31- Minor Damage Useable

    22- 1/2 Size Pcs

    22- Edge Pcs

    79 Ln Ft Ridge Cap

    1 - Ridge Cap End Piece

    RE:How to Save Money on Your Winter Heating Bills

    Links to this post


              • Did the first Snow of the Year catch you unprepared for winter?
              • Is there enough insulation in your attic, walls, or floor?
              • Do you feel cold air drafts around your windows and doors?
              • Are your Heating bills higher this year than past years?
              • Have you chosen to become an active participant to Reduce the Earth's Climate Change?
    If you answered YES to any of the above questions its not too late to make your Building more Energy Efficient
        • Insulation Levels [R-Value] For the St Louis Region (suggestions by the US Dept of Energy)
    1. Attic Insulation Level Should be a Minimum Level R-49
    2. Wall Insulation Level Minimum Level R-13
    3. Flooring Insulation Minimum Level R-30
    4. Basement Interior Wall Minimum Level R-11
    Stop Cold Air Drafts in the Exterior Walls of Your Building by
    1. Installing Weather Stripping around your Doors and Windows
    2. Seal all Exterior Wall Electrical Boxes with Electrical Box Sealer
    3. Seal Exterior Obtrusion's in Exterior Walls with Caulk or Spray Foam
    Additional Insulation Information can be found:Insulating Roofs, Walls, and Floors , Attic Insulation and Attic Energy Solutions , Roof and Attic Ventilation , Fall Home Check Up Guide with Photos

    Scotts Contracting is available to assist you in Lowering your Buildings Energy Needs- Click here to email: scottscontracting@gmail.com for any additional questions or to request a Free Green Site Evaluation.
    NOTE: For Every $1-Dollar Spent on Weatherization will Return a $2 Savings on your Energy Bills

    Scotts Contracting Guarantees that with proper insulation levels and
    stopping the Cold Air Drafts in your Building you will save money on your Heating Bills.Scotty

    Email scottscontracting@gmail.com and Scotty will provide a Free Estimate to Fix any of the Above Issues on your Home. I can also provide a Cost Saving Analysis using: eQUEST® Building Performance Software, that will provide a ROI on your Investment.

    (NOTE: I use the eQUEST® Building Performance Software for determining Cost Effective Solutions for: a detailed comparative analysis of building designs and technologies by applying sophisticated building energy use simulation techniques ...accomplished by combining schematic and design development building creation wizards, an energy efficiency measure (EEM) wizard and a graphical results display module with a complete up-to-date DOE-2 (version 2.2) building energy use simulation program.  You can read the eQUEST Overview to get a more complete summary of the features and capabilities of this excellent program.) 

    Weatherization doesn't cost it Saves! - Rule of Thumb: For Every $1 Spent on Weatherization- You will Save $2 on your Home's Energy Bills
    • Example: By adding ___ Inches of Insulation you will save $__ amount on the Energy needed to heat your Home= Lower Heating Bills and Greater Comfort Levels
    Additional Green Blog Posts:Energy Star Home Improvement Tips ,Insulation and Thermal Performance ,Which Kind Of Insulation Is Best? ,Radiant Barriers for your Attic,Insulating Roofs, Walls, and Floors, Roof and Attic Ventilation

    Email scottscontracting@gmail.com and Scotty will provide a Free Estimate to Fix any of the Above Issues on your Home.

    --
    Scott's Contracting
    scottscontracting@gmail.com

    New Solar Roofing Option is Win-Win

    Links to this post
    On Tue, Nov 16, 2010 at 9:13 AM, Scott's Contracting <scottscontracting@gmail.com> wrote:

    A Roof that: Generates Electricity is a Win-Win for Generating Clean Electricity and Protecting your Home-Scotty

    Does your Shingle Roof need Replaced? Consider a Roofing Shingle that also creates Electricity.  The new DOW POWERHOUSE™ Solar Shingle Received UL Certification as a Roofing Material that creates Clean Green Energy via the Integrated Solar Photovoltaic Electricity Producing System. 

    The DOW™ POWERHOUSE™ solar shingle has chosen thin-film CIGS (Copper Indium Gallium deSelenide) as the PV material in the Solar Shingle to convert the Suns Rays into use-able Electricity for your Home and Business.

    DOW™ POWERHOUSE™ solar shingle will become available to the US public mid 2011.  Till then Scotts Contracting will be researching the Electrical Out-Put, Efficiency, and Other variables that are needed to determine if the Solar Shingle is a cost-effective option for your Integrated Roofing and Solar Photovoltaic Project. 


    Prior Articles Here:
    Oct 19, 2010-$1 billion investment Dow Chemical announced last February it is making to build a manufacturing plant in Michigan for its shingle-integrated solar PV technology.


    DOW POWERHOUSE™ Solar Shingles Receive UL Certification


    © Business Wire 2010
    2010-11-02 13:12:32 -

    Today, The Dow Chemical Company (NYSE: DOW) and Underwriters Laboratories (UL) announced that the DOW™ POWERHOUSE™ Solar Shingle is the first residential solar roofing shingle with an integrated connection system to receive Underwriters Laboratories (UL) safety certification.

    The DOW™ POWERHOUSE™ Solar Shingle is a ground-breaking photovoltaic solar panel in the form of a solar roofing shingle that can be integrated into rooftops with standard asphalt shingle materials. It reduces installation time and complexity using a revolutionary system design that eliminates on-roof wiring, minimizes through-roof penetrations, and allows the product to be installed in the same manner as a standard roofing shingle.


    "The receipt of UL safety certification represents the successful completion of a rigorous and comprehensive multi-test process for the DOW™ POWERHOUSE™ Solar Shingles," said Dow Solar Vice President, Jane Palmieri.

    "This is another important milestone towards the planned 2011 commercialization of Dow's solar shingles, and represents a
    crucial third-party validation of the safety of this product.


    We are dedicated to making solar easy for homeowners, builders, and roofing contractors who already trust the performance and safety of building products bearing the Dow brand."

    Given the new and unique nature of the DOW™ POWERHOUSE™ Solar Shingle, Dow Solar worked closely with UL - a trusted global resource for product safety certification and compliance solutions - to indentify a series of rigorous tests to assess the safety of the unique design and of all the elements of the combined solar and roofing product. The final listing awarded to the DOW™ POWERHOUSE™ Solar Shingles represents compliance to a diverse sequence of UL's safety and building standards, specifically, UL 746, 1703, 1897, 790, 486 and 514. Over 50 individual tests were conducted to assess the safety of the DOW™ POWERHOUSE™ Solar Shingles against building code standards, including wind and fire resistance, and electrical code requirements, such as proper wiring and photovoltaic (PV) connections.

    "UL has been leading the development of PV equipment testing methodologies and standards since the 1980s, and has contributed to the safe operation of PV equipment by providing safety testing and certification services for PV equipment manufacturers worldwide," said Jeff Smidt, Vice President and General Manager for UL's Global Energy business. "In the case of Dow's solar shingles, we had to take a unique approach in order to test the product as both a roofing shingle and a PV system. We are proud to provide the UL mark to this first-of-its-kind solar shingle from Dow."

    In addition to the vitally important design and material safety tests performed by UL, Dow will continue with its own reliability and durability testing in support of commercialization. Dow is currently performing tests on installed systems of DOW™ POWERHOUSE™ Solar Shingles in addition to individual shingles in order to assess the durability of the product, utilizing Design for Reliability and Physics of Failure methodologies to measure performance against weather, extreme temperatures and more.

    Dow has chosen thin-film CIGS (Copper Indium Gallium deSelenide) as the PV material in the DOW™ POWERHOUSE™ solar shingle, and Global Solar Energy (Tucson, AZ) was selected as the preferred supplier in support of the product launch. CIGS technology offers the best balance of low cost and highest sunlight conversion efficiency of the commercialized thin film technologies available today, and the flexible foil substrate of the Global Solar Energy CIGS cells provides the necessary level of flexural durability to allow the DOW™ POWERHOUSE™ Solar Shingle to perform reliably in a demanding application environment.

    Breaking the traditional barriers to residential solar adoption – complexity, affordability and aesthetics – this technology offers the missing link needed by the energy industry to drive solar adoption across the U.S., and will bring the possibility of safe and reliable solar power to American households. The DOW™ POWERHOUSE™ Solar Shingle is expected to be commercially available in select U.S. markets by mid 2011.



    About DOW™ POWERHOUSE™

    In 2007, Dow received a $20 million grant from the U.S. Department of Energy as part of its Solar America Initiative to develop "building integrated" solar arrays for the residential and commercial markets. In October 2009, Dow Solar unveiled the DOW™ POWERHOUSE™ Solar Shingle as the first in a portfolio of building related solar energy generating products.

    Since its introduction, the Solar Shingle has been hailed as revolutionary, including being named one of the "50 Best Inventions of 2009" by TIME magazine.


    The innovative product design provides an unprecedented integrated roof appearance and simplified installation. It combines a roofing shingle with a solar cell, enabling the DOW™ POWERHOUSE™ Solar Shingle to be installed by a roofer along with standard asphalt roofing materials.

    This makes the DOW™ POWERHOUSE™ Solar Shingle an easy choice for homeowners looking for a residential solar solution that is easy to install and aesthetically pleasing. Building Integrated Photovoltaic (BIPV) products from Dow Solar are evidence that Dow is focused on developing energy alternatives and expanding Dow's commitment to use chemistry to solve the world's energy challenges. More information about Dow Solar can be found at www.dowsolar.com : .


    About Dow

    Dow combines the power of science and technology with the "Human Element" to passionately innovate what is essential to human progress.

    The Company connects chemistry and innovation with the principles of sustainability to help address many of the world's most challenging problems such as the need for clean water, renewable energy generation and conservation, and increasing agricultural productivity. Dow's diversified industry-leading portfolio of specialty chemical, advanced materials, agrosciences and plastics businesses delivers a broad range of technology-based products and solutions to customers in approximately 160 countries and in high growth sectors such as electronics, water, energy, coatings and agriculture. In 2009, Dow had annual sales of $45 billion and employed approximately 52,000 people worldwide. The Company's more than 5,000 products are manufactured at 214 sites in 37 countries across the globe. References to "Dow" or the "Company" mean The Dow Chemical Company and its consolidated subsidiaries unless otherwise expressly noted. More information about Dow can be found at www.dow.com : .



    ®TM Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow





    For editorial information:Greg BaldwinThe Dow

    Chemical Company+1 989 638-0745 gbaldwin@dow.com : mailto:gbaldwin@dow.com orChris
    GramsGolinHarris+1 312 729-4364 cgrams@golinharris.com : mailto:cgrams@golinharris.com orKate
    NigroDow Solar+1 989 638 9629 knigro@dow.com : mailto:knigro@dow.com




    --
    Scott's Contracting
    scottscontracting@gmail.com
    http://www.stlouisrenewableenergy.blogspot.com
    http://www.stlouisrenewableenergy.com
    scotty@stlouisrenewableenergy.com

    Radiant Barriers

    StLouis, MO St Louis, MO 63109, USA Links to this post
    Information Provided by:Scotty,Scott's Contracting GREEN BUILDER, St Louis "Renewable Energy" Missouri; http://stlouisrenewableenergy.blogspot.com; contact scottscontracting@gmail.com for additional information or to Schedule a "Free Green Site Evaluation"

    Scotts Contracting Home Repair and Green Building Entrepreneur

    Posting is Follow up on Radiant Barrier Issues:  http://stlouisrenewableenergy.blogspot.com/2010/06/cool-roofs-materials-options-insulation.html

    August 2000-From Journal of Light Construction Radiant Heat Barriers


    Q. I have seen many ads for radiant barriers designed to save energy. Is there any evidence that these radiant barriers can reduce home energy costs? If so, in what climates are they most effective? How should they be installed?

    A. David Beal, building scientist at the Florida Solar Energy Center, responds: In cooling climates, radiant barriers can and do save cooling energy. Testing at the Florida Solar Energy Center and other laboratories have consistently shown that a radiant barrier can reduce the amount of heat entering a home through the ceiling by 25 to 40 percent. The amount of energy saved depends on the level of conventional insulation in the attic. For those with a thick layer of attic insulation, a 40% reduction in the small amount of heat coming through the ceiling is correspondingly small. For those with minimal attic insulation, on the other hand, a 40% reduction in heat flow through the ceiling is a much larger amount.
    Two rules of thumb:
    • If you have R-30 or better attic insulation, the payback period for the installation of a radiant barrier may be long, although it will save energy.
    • In a cooling climate, a house with a radiant barrier and R-19 attic insulation, compared to R-19 with no radiant barrier, should see a reduction in cooling energy requirements of about 10 to 12 percent.
    Radiant barriers are not recommended in heating-dominated climates. To my knowledge, there has been no testing of radiant barriers in a heating climate. 

    The easiest and cheapest way to install a radiant barrier in new construction is to install roof sheathing with a radiant barrier. Several manufacturers now offer OSB or plywood roof sheathing with a laminated radiant barrier. A radiant barrier system can also be installed under the bottom of the top chord of a roof truss, or to the bottom edge of rafters. Installing a radiant barrier on an attic floor is not recommended, since such barriers easily get dirty, reducing the performance of the radiant barrier significantly. For more information, contact the Florida Solar Energy Center at 407/638-1000. 

    Another Article from JLC
    October 1992 Do radiant barriers save energy?
    Steve Andrews responds: Yes, radiant barriers in vented attics can cut cooling bills by about 10%. They achieve this by reducing heat flow down through the ceiling by 40% or more. But the better question is: Are radiant barriers cost-effective? The answer is also yes, but only in the right climates, only when properly installed, and only at the right price (see map).
    Here�s a summary of the latest information:

    Climate. The NAHB Research Center�s study (funded by Eagle Shield) promised to yield good information on radiant barrier performance in cold climates, but it has hit contractual snags. So climate-related advice hasn�t changed: Radiant barriers in attics make the most sense in locations where there are 2,000 cooling degree days or more (see map at right). They may also make sense in more moderate climates where annual cooling bills still exceed annual heating bills (excluding mild sections of the West Coast). In cold climates, radiant barriers can make sense in a crawlspace, but this remains unproven for attics.

    Properly installed. For attics, staple the barrier beneath the rafters, drape it over the roof trusses before the decking goes on, or staple it directly to the bottom of the roof decking � shiny side down in all cases (see illustration at left). Make sure you vent the attic, since this is the best way to cool this space. Research shows that laying a radiant barrier flat over horizontal attic insulation can cut radiant barrier performance by up to 50% after five years due to dust buildup.

    Cost. If you buy material directly from a manufacturer, expect to pay between 7� and 15� per square foot, depending on the quality of paper backing and fiber mesh reinforcement. These two features can dramatically reduce tearing during installation; test this by ripping up samples before you buy. According to the Florida Solar Energy Center, if a homeowner pays about 20� per square foot for the installed barrier, the simple payback will be as little as five years in a cooling climate (based on electricity costs of 8� per Kwh). The greater the cooling load and utility costs, the faster the payback will be.

    Steve Andrews is a residential energy consultant and freelance writer in Denver, Colo.

    In attics, staple the radiant barrier beneath the rafters, drape it over the roof trusses, or staple it to the bottom of roof decking. In all cases, install the foil shiny side down and vent the roof. 

    Radiant barriers make the most economic sense in the deep South. 



    Radiant Barrier Information provided by: http://www.ornl.gov/sci/roofs+walls/radiant/rb_01.html

      

    DOE/CE-0335P
    June 1991


    Department of Energy
    Assistant Secretary
    Energy Efficiency and Renewable Energy 

    Building Envelope Research
    Oak Ridge National Laboratory

    For more information, contact the program manager for Building Envelope Research:
    André O. Desjarlais
    Oak Ridge National Laboratory
    P. O. Box 2008, MS 6070
    Oak Ridge, TN 37831-6070

    E-mail Andre Desjarlais


    Contents:

    Introduction
    Effect of Radiant Barrier on Heating and Cooling Bills
    Important Non-Energy Considerations
    Installation Procedures
    Appendix
    Key to Abbreviations
    Information Services
    About This Fact Sheet


    Introduction

    What is a radiant barrier?
    Radiant barriers are materials that are installed in buildings to reduce summer heat gain and winter heat loss, and hence to reduce building heating and cooling energy usage. The potential benefit of attic radiant barriers is primarily in reducing air-conditioning cooling loads in warm or hot climates. Radiant barriers usually consist of a thin sheet or coating of a highly reflective material, usually aluminum, applied to one or both sides of a number of substrate materials. These substrates include kraft paper, plastic films, cardboard, plywood sheathing, and air infiltration barrier material. Some products are fiber reinforced to increase the durability and ease of handling.
    Radiant barriers can be used in residential, commercial, and industrial buildings. However, this fact sheet was developed only for applications of radiant barriers in ventilated attics of residential buildings. For information on other applications, see the references at the end of the Fact Sheet.
    How are radiant barriers installed in a residential attic?
    Radiant barriers may be installed in attics in several configurations. The simplest is to lay the radiant barrier directly on top of existing attic insulation, with the reflective side up. This is often called the attic floor application. Another way to install a radiant barrier is to attach it near the roof. The roof application has several variations. One variation is to attach the radiant barrier to the bottom surfaces of the attic truss chords or rafter framing. Another is to drape the radiant barrier over the tops of the rafters before the roof deck is applied. Still another variation is to attach the radiant barrier directly to the underside of the roof deck.
    How do radiant barriers work?
    Radiant barriers work by reducing heat transfer by thermal radiation across the air space between the roof deck and the attic floor, where conventional insulation is usually placed. All materials give off, or emit, energy by thermal radiation as a result of their temperature. The amount of energy emitted depends on the surface temperature and a property called the "emissivity" (also called the "emittance"). The emissivity is a number between zero (0) and one (1). The higher the emissivity, the greater the emitted radiation.
    A closely related material property is the "reflectivity" (also called the "reflectance"). This is a measure of how much radiant heat is reflected by a material. The reflectivity is also a number between 0 and 1 (sometimes, it is given as a percentage, and then it is between 0 and 100%). For a material that is opaque (that is, it does not allow radiation to pass directly through it), when the emissivity and reflectivity are added together, the sum is one (1). Hence, a material with a high reflectivity has a low emissivity, and vice versa. Radiant barrier materials must have high reflectivity (usually 0.9, or 90%, or more) and low emissivity (usually 0.1 or less), and must face an open air space to perform properly.
    On a sunny summer day, solar energy is absorbed by the roof, heating the roof sheathing and causing the underside of the sheathing and the roof framing to radiate heat downward toward the attic floor. When a radiant barrier is placed on the attic floor, much of the heat radiated from the hot roof is reflected back toward the roof. This makes the top surface of the insulation cooler than it would have been without a radiant barrier and thus reduces the amount of heat that moves through the insulation into the rooms below the ceiling.
    Under the same conditions, a roof mounted radiant barrier works by reducing the amount of radiation incident on the insulation. Since the amount of radiation striking the top of the insulation is less than it would have been without a radiant barrier, the insulation surface temperature is lower and the heat flow through the insulation is reduced.
    Radiant barriers can also reduce indoor heat losses through the ceiling in the winter. Radiant barriers reduce the amount of energy radiated from the top surface of the insulation, but can also reduce beneficial heat gains due to solar heating of the roof. The net benefits of radiant barriers for reducing winter heat losses are still being studied.
    How does a radiant barrier differ from conventional attic insulation?
    Radiant barriers perform a function that is similar to that of conventional insulation, in that they reduce the amount of heat that is transferred from the attic into the house. They differ in the way they reduce the heat flow. A radiant barrier reduces the amount of heat radiated across an air space that is adjacent to the radiant barrier. The primary function of conventional insulation is to trap still air within the insulation, and hence reduce heat transfer by air movement (convection). The insulation fibers or particles also partially block radiation heat transfer through the space occupied by the insulation.
    Conventional insulations are usually rated by their R-value. Since the performance of radiant barriers depends on many variables, simple R-value ratings have not been developed for them.
    What are the characteristics of a radiant barrier?
    All radiant barriers have at least one reflective (or low emissivity) surface, usually a sheet or coating of aluminum. Some radiant barriers have a reflective surface on both sides. Both types work about equally well, but if a one-sided radiant barrier is used, the reflective surface must face the open air space. For example, if a one-sided radiant barrier 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 loads.
    Emissivity is the property that determines how well a radiant barrier will perform. This property is a number between 0 and 1, with lower numbers indicating better potential for performance. The emissivity of typical, clean, unperforated radiant barriers is about 0.03 to 0.05. Hence they will have a reflectivity of 95 to 97 percent. Some materials may have higher emissivities. It is not always possible to judge the emissivity just by visual appearance. Measured emissivity values should be part of the information provided by the manufacturer.
    A radiant barrier used in the attic floor application must allow water vapor to pass through it. This is necessary because, during the winter, if there is no effective vapor retarder at the ceiling, water vapor from the living space may condense and even freeze on the underside of a radiant barrier lying on the attic floor. In extremely cold climates or during prolonged periods of cold weather, a layer of condensed water could build up. In more moderate climates, the condensed water could evaporate and pass through the radiant barrier into the attic space. While most uniform aluminum coatings do not allow water vapor to pass through them, many radiant barrier materials do allow passage of water vapor. Some allow water vapor passage through holes or perforations, while others have substrates that naturally allow water vapor passage without requiring holes. However, excessively large holes will increase the emissivity and cause a reduction in the radiant barrier performance. The ability to allow water vapor to pass through radiant barrier materials is not needed for the roof applications.
    What should a radiant barrier installation cost?
    Costs for an attic radiant barrier will depend on several factors, including the following:
    • Whether the radiant barrier is installed by the homeowner or by a contractor.
    • Whether the radiant barrier will be installed in a new home (low cost) or in an existing home (possibly higher cost if done by a contractor).
    • What extra "features" are desired; e.g., a radiant barrier with perforations and reinforcements may be more expensive than a "basic" radiant barrier.
    • Any necessary retrofit measures such as adding venting (soffit, ridge, etc.)
    • Whether the radiant barrier is installed on the attic floor or on the rafters.
    Radiant barrier costs vary widely. As with most purchases, some comparison shopping can save you money. A survey of nine radiant barrier manufacturers and contractors representing 14 products, taken by the Reflective Insulation Manufacturers Association (RIMA) in 1989, shows the installed costs of radiant barriers to range as shown in Table 1. In some cases, radiant barriers are included in a package of energy saving features sold to homeowners. When considering a "package deal", you may want to ask for an itemized list that includes material and installation costs for all measures included. Then shop around to see what each item would cost if purchased individually before you make a decision.
    What should conventional insulation cost?
    Heating and cooling bills can also be reduced by adding conventional attic insulation. So that you can have some basis for comparison shopping, typical installed costs for adding various levels of insulation are given in Table 2. These costs are typical for insulation installed by contractors. Actual insulation costs will vary from region to region of the country, will vary with the type of insulation selected (blown, or loose-fill, insulation is usually lower in price than "batt" insulation), and may vary from one local contractor to another. You can expect to deduct 20% to 50% for a do-it-yourself application.
    You should always check with your local or state energy office or building code department for current insulation recommendations or see the DOE INSULATION FACT SHEET.







    Effect of Radiant Barriers on Heating and Cooling Bills

    Have heating and cooling effects been tested? At present, there is no standardized method for testing the effectiveness of radiant barriers in reducing heating and cooling bills. But numerous field tests have been performed that show, depending on the amount of existing conventional insulation and other factors, radiant barriers are effective in reducing cooling bills, and also possibly heating bills.

    Most of these field tests have been performed in warm climates where a large amount of air-conditioning is used. The Florida Solar Energy Center (FSEC) at Cape Canaveral has performed tests for a number of years using attic test sections, and has also performed tests with full-size houses. A test using a duplex house in Ocala, Florida has been performed by the Mineral Insulation Manufacturers Association. The Tennessee Valley Authority has performed a number of winter and summer tests using small test cells in Chattanooga, Tennessee. The Oak Ridge National Laboratory (ORNL) has performed a series of tests using three full-size houses near Knoxville, Tennessee. The ORNL tests included summer and winter observations. So far, very little testing has been done in climates colder than that of Knoxville. Also, little testing has been done in hot, arid climates such as the southwestern United States.

    The tests to date have shown that in attics with R-19 insulation, radiant barriers can reduce summer ceiling heat gains by about 16 to 42 percent compared to an attic with the same insulation level and no radiant barrier. These figures are for the average reduction in heat flow through the insulation path. They do not include effects of heat flow through the framing members. See Tables A1 and A2 in the Appendix for a comparison of measured performance.

    THIS DOES NOT MEAN THAT A 16 TO 42 PERCENT SAVINGS IN UTILITY BILLS CAN BE EXPECTED. Since the ceiling heat gains represent about 15 to 25 percent of the total cooling load on the house, a radiant barrier would be expected to reduce the space cooling portion of summer utility bills by less than 15 to 25 percent. Multiplying this percentage (15 to 25 percent) by the percentage reduction in ceiling heat flow (16 to 42 percent) would result in a 2 to 10 percent reduction in the cooling portion of summer utility bills. However, under some conditions, the percentage reduction of the cooling portion of summer utility bills may be larger, perhaps as large as 17 percent. The percentage reduction in total summer utility bills, which also include costs for operating appliances, water heaters, etc., would be smaller. Tests have shown that the percentage reductions for winter heat losses are lower than those for summer heat gains.

    Experiments with various levels of conventional insulation show that the percentage reduction in ceiling heat flow due to the addition of a radiant barrier is larger with lower amounts of insulation. Since the fraction of the whole-house heating and cooling load that comes from the ceiling is larger when the amount of insulation is small, radiant barriers produce the most energy savings when used in combination with lower levels of insulation. Similarly, radiant barriers produce significantly less energy savings when used in combination with high levels of insulation.

    Most of the field tests have been done with clean radiant barriers. Laboratory measurements have shown that dust on the surface of aluminum foil increases the emissivity and decreases the reflectivity. This means that dust or other particles on the exposed surface of a radiant barrier will reduce its effectiveness. Radiant barriers installed in locations that collect dust or other surface contaminants will have a decreasing benefit to the homeowner over time.

    The attic floor application is most susceptible to accumulation of dust, while downward facing reflective surfaces used with many roof applications are not likely to become dusty. When radiant barriers are newly installed, some testing shows that the attic floor application will work better than the roof applications. As dust accumulates on the attic floor application, its effectiveness will gradually decrease. After a long enough period of time, a dusty attic floor application will lose much of its effectiveness. Predictive modeling results, based on testing, suggest that a dusty attic floor application will lose about half of its effectiveness after about one to ten years.

    Testing of radiant barriers has been primarily concerned with the effect of radiant barriers on the heat gains or losses through the ceiling. Another aspect of radiant barriers may be important when air-conditioning ducts are installed in the attic space. The roof applications of radiant barriers can result in lowered air temperatures within the attic space, which in turn can reduce heat gains by the air flowing through the ducts, thus increasing the efficiency of the air-conditioning system. These changes in heat gains to attic ducts have not been tested; however, computer models have been used to make estimates of the impact on cooling bills.
    Not all field tests have been able to demonstrate that radiant barriers or even attic insulation are effective in reducing cooling bills. In a field test performed by ORNL in Tulsa, Oklahoma, using 19 full-sized, occupied houses, neither radiant barriers nor attic insulation produced air-conditioning electricity savings that could be measured. As in all field tests, these results are applicable only to houses with similar characteristics as those tested. Unique characteristics of the houses used in this field test included the facts that the houses were cooled by only one or two window air-conditioning units, that the units were able to cool only a portion of the house, and that the occupants chose to limit their use of the units (initial air-conditioning electricity consumption averaged 1664 kilowatt-hours per year or about $119 per year).

    How much will I save on my heating and cooling bills?
    Your savings on heating and cooling bills will vary, depending on many factors. Savings will depend on the type of radiant barrier application, the size of your house, whether it is a ranch style or a two story house, the amount of insulation in the attic, effectiveness of attic ventilation, the color of the roof, the thermostat settings, the tightness of the building envelope, the actual weather conditions, the efficiency of the heating and cooling equipment, and fuel prices.

    Research on radiant barriers is not complete. Estimates of expected savings, however, have been made using a computer program that has been checked against some of the field test data that have been collected. These calculations used weather data from a number of locations to estimate the reductions in heating and cooling loads for a typical house. These load reductions were then converted to savings on fuel bills using average gas furnace and central air-conditioner efficiencies and national average prices for natural gas and electricity.
    ASSUMPTIONS. For these calculations, the house thermostat settings were taken to be 78F in the summer and 70F in the winter. In the summer, it was assumed that windows would be opened when the outdoor temperature and humidity were low enough to take advantage of free cooling. Also, it was assumed that the roof shingles were dark, and that the roof was not shaded. The furnace efficiency used was 65 percent, and the air-conditioner coefficient of performance (COP) was 2.34. Fuel prices used were 52.7 cents per therm (hundred cubic feet) for natural gas and 7.86 cents per kilowatt-hour for electricity.

    Factors that could make your savings larger than the ones calculated would be: a summer thermostat setting lower than 78F, a winter thermostat setting higher than 70F, keeping the windows closed at all times, lower efficiency furnace or air-conditioner, or higher fuel prices. Factors that could make your savings less than the ones calculated would be: a summer thermostat setting higher than 78F, a winter thermostat setting lower than 70F, light colored roof shingles, shading of the roof by trees or nearby structures, higher efficiency furnace or air-conditioner, and lower fuel prices.

    A standard economic calculation was then performed that converts the dollar savings from periods in the future to a "present value". The dollar savings were also adjusted to account for estimates of how prices for natural gas and electricity are predicted to rise in future years. This calculation gives a "present value savings" in terms of dollars per square foot of ceiling area. When this value is multiplied by the total ceiling area, the result is a number that can be compared with the cost of installing a radiant barrier. If the present value savings for the whole ceiling is greater than the cost of a radiant barrier, then the radiant barrier will be "cost effective." A real discount rate of 7 percent, above and beyond inflation, and a life of 25 years were used in the calculations.

    Tables 3, 4, and 5 give present value savings for radiant barriers based on average prices and equipment efficiencies. Table 3 applies to the attic floor application, where the effects of dust accumulation have been taken into account. Since dust will accumulate at different rates in different houses, and since the effect of dust on performance is not well known, ranges of values are given for this application. Table 4 applies to radiant barriers attached to the bottoms of the rafters, while Table 5 applies to radiant barriers either draped over the tops of the rafters or attached directly to the underside of the roof deck. For comparison purposes, the same computer program has also been used to estimate present value savings for putting additional insulation in the attic; these values are listed in Table 6. By examining several options, the consumer can compare the relative savings that may be obtained versus the cost of installing the option. Generally, the option with the largest net savings (that is, the present value savings minus the cost) would be the most desirable. However, personal preferences will also enter into a final decision.

    If you want a better estimate based on your local fuel prices or other equipment efficiencies, you may use the worksheet in the Appendix. Local fuel prices may be obtained from your local utilities.

    Examples of Use of Present Value Tables

    Example 1
    I live in Orlando, Florida in an 1800 square foot ranch style house. I have R-11 insulation in my attic, and the air-conditioning ducts are in the attic. A contractor has quoted a price for a radiant barrier installed on the bottoms of my rafters and on the gable ends for $400. Would this be a good investment?
    For this type of radiant barrier, the appropriate table is Table 4. For Orlando with R-11 insulation, the present value savings is listed as $0.32 when the air-conditioning ducts are in the attic. Multiplying this value by 1800 square feet gives a total of $576. This value exceeds the quoted cost of the radiant barrier of $400, and thus this would be a good investment.

    Example 2
    I live in Minneapolis, Minnesota in a 2400 square foot two-story house. I have R-19 insulation in my attic, and have no air-conditioning ducts in the attic. A contractor has quoted a price for a radiant barrier installed on the bottoms of my rafters and on the gable ends for $250. Would this be a good investment? Would investment in another layer of R-19 insulation be a better investment? A contractor has quoted a price of $564 for adding this insulation.

    For this type of radiant barrier, the appropriate table is Table 4. For Minneapolis with R-19 insulation, the present value savings is listed as $0.08 when there are no air-conditioning ducts in the attic. Since the house is two-story, the ceiling area is 1200 square feet. Multiplying $0.08 by 1200 gives a total of $96. This value is less than the quoted cost of the radiant barrier of $250 and thus this would not be a good investment.
    For adding another layer of insulation, the appropriate table is Table 6. For Minneapolis, this table gives a present value savings of $0.57 for adding a layer of R-19 insulation to an existing layer of R-19 insulation. Multiplying this value by 1200 square feet gives a total of $684. This value exceeds the quoted cost of the insulation, and thus this would be a good investment.






    Important Non-Energy Considerations

    Potential for moisture condensation
    Condensation of moisture can be a concern when a radiant barrier is installed on the attic floor directly on top of conventional 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 any problem because attic ventilation will carry excess vapor away. During cold weather, a radiant barrier on top of the insulation could cause water vapor to condense on the barrier's underside.

    Condensation of large amounts of water could lead to the following problems: 1) the existing insulation could become wet and lose some of its insulating value, 2) water spots could appear on the ceiling, and 3) under severe conditions, the ceiling framing could rot.

    Some testing has been performed to determine the potential for moisture condensation with perforated radiant barriers laid on top of the insulation. A test was conducted during the winter near Knoxville, Tennessee, using houses that were operated at much higher-than-normal indoor relative humidities. Since this testing did not reveal any significant moisture condensation problems, it is expected that moisture condensation will not be a problem in climates warmer than that of Knoxville. Further testing of radiant barriers is needed to determine if moisture condensation is a problem in climates colder than that of Knoxville.

    One precaution for preventing potential moisture problems is the use of perforated or naturally permeable radiant barriers. The higher the perm rating, the less potential for problems. Avoiding high indoor relative humidities, sealing cracks and air leaks in the ceiling, using a vapor retarder below the attic insulation, and providing for adequate attic ventilation are additional precautions.

    Attic ventilation
    Attic ventilation is an important consideration. With adequate ventilation, radiant barriers will perform better in summer and excess water vapor will be removed in winter. Unfortunately, specific recommendations for the best type and amount of attic ventilation for use with radiant barriers are not available. Model building codes have established guidelines for the amount of attic ventilation area per square foot of attic floor area to minimize the occurrence of condensation. These guidelines specify one square foot of net free ventilation area for each 150 square feet of attic floor area. This ratio may be reduced to 1 to 300 if a ceiling vapor retarder is present or if high (for example, ridge or gable vents) and low (soffit vents) attic ventilation is used. Since part of the vent area is blocked by meshes or louvers, the net free area of a vent is smaller than its overall dimensions.

    Effect of radiant barriers on roof temperatures
    Field tests have shown that radiant barriers can cause a small increase in roof temperatures. Roof mounted radiant barriers may increase shingle temperatures by 2 to 10oF, while radiant barriers on the attic floor may cause smaller increases of 2F or less. The effects of these increased temperatures on roof life, if any, are not known.

    Fire ratings
    The fire ratings of radiant barriers are important because flame and smoke characteristics of materials exposed to ambient air are critical.
    TO MEET CODE, A RADIANT BARRIER MUST BE RATED EITHER CLASS A BY THE NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) OR CLASS I BY THE UNIFORM BUILDING CODE (UBC).
    To obtain these ratings, a material must have an ASTM E-84 Flame Spread Index of 25 or less and a Smoke Developed Index of 450 or less. Look for these ratings either printed on the product, or listed on material data sheets provided by the manufacturer.
    Previous Section - Effect of Radiant Barriers on Heating and Cooling BIlls
    Next Section - Installation Procedure



    Installation Procedures

    Most residential roofs provide some type of attic or airspace that can accommodate an effective radiant barrier system. In new residential construction, it is fairly easy to install a radiant barrier system. The following images show five possible locations for the installation of an attic radiant barrier system.

    Location 1 is a relatively new application, where the radiant barrier material is attached directly to the underside of the roof deck.

    Location 2 may offer advantages to the builder during construction of a new house. Before the roof sheathing is applied, the radiant barrier is draped over the rafters or trusses in a way that allows the product to droop 1-1/2 to 3 inches between each rafter.
    In Locations 3 and 4, the radiant barrier is attached to either the faces or bottoms of the rafters or top chords of the roof trusses. Locations 3 and 4 may be used with either new construction, or with retrofit of an existing house. With either Location 2, 3 or 4, the space between the roof sheathing and the radiant barrier provides a channel through which warm air can move freely, as shown in Figure 2.
    In Location 5, the radiant barrier is laid out on the attic floor over the top of existing attic insulation. As discussed previously, this location is susceptible to the effects of dust accumulation. This location is not appropriate when a large part of the attic is used for storage, since the radiant barrier surface must be exposed to the attic space. Also, kitchen and bathroom vents and recessed lights should not be covered with the radiant barrier.

    To obtain the best performance with radiant barriers installed in Locations 1 through 4, radiant barrier material should also be installed over the gable ends. For attics that are open to the space over garages or carports, the radiant barrier should extend eight feet or more into the garage or carport to achieve the same effect as installing a radiant barrier on the gable ends. It is not necessary to cover the gable ends with Location 5.
    Radiant barriers that are reflective on one or both sides may be used with any of these locations. However, if the radiant barrier is reflective on only one side, the reflective side must face toward the main attic space for Locations 1 and 5. Since a surface facing downwards is less likely to have dust settle on it, it is also recommended that the reflective side face downwards toward the main attic space for Locations 2, 3, and 4.
    Since proper attic venting is important to obtain the best performance of the radiant barrier, some modification in the attic vents may be required to achieve expected performance. Where no ridge or gable vents exist, it is recommended that one or the other be installed. Always check existing ridge vent systems to ensure that roofing paper is not blocking the vent opening, and check the soffit vents to ensure that they have not been covered with insulation.

    When installing a radiant barrier, care should be taken not to compress existing insulation present in the attic. The effectiveness of the existing insulation is dependent upon its thickness, so if it is compressed, its R-value is decreased. For instance, an R-19 batt compressed to 3-1/2 inches (to top of 2X4 attic floor joists) would now be approximately an R-13 batt.

    Safety considerations
    • The installer should wear proper clothing and equipment as recommended by the radiant barrier manufacturer. Handling conventional insulation may cause skin, eye, and respiratory system irritation. If in doubt about the effects of the insulation, protective clothing, gloves, eye protection, and breathing protection should be worn.
    • Be especially careful with electrical wiring, particularly around junction boxes and old wiring. Never staple through, near, or over electrical wiring. Repair any obvious frayed or defective wiring in advance of radiant barrier installation.
    • Work in the attic only when temperatures are reasonable.
    • Work with a partner. Not only does it make the job go faster, it also means that you'll have assistance should a problem occur.
    • If the attic is unfinished, watch where you walk. If you step in the wrong place, you could fall through the ceiling. Step and stand only on the attic joists or trusses or the center of a strong moveable working surface.
    • Watch your head. In most attics, roofing nails penetrate through the underside of the roof. A hard hat may be of some use.
    • Make sure that the attic space is well ventilated and lighted.
    • Do not cover any recessed lights or vents with radiant barrier material (attic floor application).


    Appendix

    Test Results
    Most tests of radiant barriers have measured the reduction in heat flow through the ceiling caused by adding a radiant barrier. The test results are usually expressed in terms of a percentage ceiling heat flow reduction. Table A1 gives a summary of measured ceiling heat flow reductions for summer conditions when radiant barriers were added in various locations to existing R-19 conventional insulation. Table A2 gives a summary for winter conditions. Table A1 shows that, while there are some variations in the summer data, there is also a good amount of consistency. For winter conditions, there are wider variations in the data and less consistency, but the percentage reductions for winter are less than for summer. Tests by the Tennessee Valley Authority and the Mineral Insulation Manufacturers Association show that increasing the insulation level from R-19 to R-30 instead of installing a radiant barrier reduces the ceiling heat flow by 27 to 33 percent. REMEMBER THAT THE NUMBERS GIVEN IN THE TABLES ARE PERCENTAGE REDUCTIONS FOR THE HEAT FLOW THROUGH THE CEILING; THEY ARE NOT PERCENTAGE REDUCTIONS FOR TOTAL ENERGY USED BY THE AIR-CONDITIONING OR HEATING EQUIPMENT.


    Energy Savings Worksheet
    If you want a more accurate estimate of your energy savings than the ones given in Tables 3-6, you may use the Worksheet given in this Appendix. Step-by-step instructions are as follows:
    1. Examine air-conditioning unit, determine SEER (for a key to abbreviations, see page 24). Divide SEER by 3.413 to obtain efficiency or COP and enter result in Box A. Typical efficiencies are given in Table X. If SEER is unknown, enter 2.3 in Box A.
    2. Examine heating equipment. Determine whether it is a gas furnace, oil furnace, heat pump, electric furnace, or electric baseboard heating. Determine efficiency, and enter in Box B. Typical efficiencies are given in Table X. If efficiency is unknown, enter 0.65 in Box B.
    3. Obtain cost of electricity, either by examining your electric bills or by contacting your utility. Multiply the cost in cents per kilowatt-hour by 2.93 and enter result in Box C.
    4. Obtain cost of heating fuel, either by examining your fuel bills or by contacting your utility.
      If you heat with gas, multiply the cost in dollars per CCF (or therm) by 10 and enter result in Box D.
      If you heat with oil, multiply the cost in dollars per gallon by 7.15 and enter result in Box D.
      If you heat with electricity (including a heat pump), multiply the cost in cents per kilowatt-hour by 2.93 and enter result in Box D.
    5. Divide the value in Box C by the value in Box A and enter result in Box E.
    6. Divide the value in Box D by the value in Box B and enter result in Box F.
    7. Inspect your attic to determine the type and level of conventional attic insulation, the area of the ceiling, and whether or not the cooling ducts run through the attic. The level of insulation may be estimated with the following chart for insulation thickness (in inches) as a function of insulation type and level:
      Type of Insulation R-11 R-19 R-30 R-38
      Fiberglass batts
      Loose-fill fiberglass
      Loose-fill cellulose
      3.5"
      4.75"
      3.75"
      6.25"
      8.25"
      6.50"
      9.75"
      12.75"
      10.50"
      12.5"
      16"
      13"
      The area of the ceiling is determined by estimating the length and width (in feet) of the ceiling and multiplying these two values together. Enter this value in Box 1.
    8. a. If you plan to install a radiant barrier (RB)
      Go to Table Y1. Locate a city that is near your location and then read off the value for that city for the level of insulation in your attic. Then multiply this value by one of the following factors depending upon the type of radiant barrier you plan to install, and enter the result in Box 2:
      Radiant Barrier Description Configuration Factor
      For low range of values for dusty attic floor RB 0.16
      For high range of values for dusty attic floor RB 0.65
      For RB attached to rafter bottoms, and with no ducts in attic 0.78
      For RB attached to rafter bottoms, and with ducts in attic,
      - and with R-11 conventional attic insulation 0.98
      - or with R-19 conventional attic insulation 1.07
      - or with R-30 conventional attic insulation 1.15
      - or with R-38 conventional attic insulation 1.22
      For RB draped over tops of rafters or attached to roof deck,
      - and with no ducts in attic 0.68
      For RB draped over tops of rafters or attached to roof deck, and with ducts in attic,
      - and with R-11 conventional attic insulation 0.86
      - or with R-19 conventional attic insulation 0.93
      - or with R-30 conventional attic insulation 1.01
      - or with R-38 conventional attic insulation 1.07
      b. If you plan to install more insulation.
      Go to Table Y3. Locate a city near your location and read off the value for that city and for the initial and final levels of attic insulation. Note that values in the table may be added in steps. For example, if you start with R-11 insulation and want to go to the R-38 level, add the values for going from R-11 to R-19, for R-19 to R-30, and for R-30 to R-38. Enter the value in Box 2.
    9. a. If you plan to install a radiant barrier.
      Go to Table Y2. Locate the same city that you used for Step 8a and read off the value for that city for the level of insulation in your attic. Then multiply this value by one of the following factors depending upon the type of radiant barrier you plan to install, and enter the result in Box 3:
      RAdiant Barrier Description Configuration Factor
      For low range of values for dusty attic floor RB 0.24
      For high range of values for dusty attic floor RB 0.61
      For RB attached to rafter bottoms 0.88
      For RB draped over tops of rafters or attached to roof deck 0.82
      b. If you plan to install more insulation.
      Go to Table Y4. Locate the same city that you used for Step 8b and read off the value for that city and for the initial and final levels of attic insulation. Note that values in the table may be added in steps. For example, if you start with R-11 insulation and want to go to the R-38 level, add the values for going from R-11 to R-19, for R-19 to R-30, and for R-30 to R-38. Enter the value in Box 3.
    10. Multiply the values in Boxes 1, 2, and E together, and divide the result by 1,000,000. Enter the result in Box 4.
    11. Multiply the values in Boxes 1, 3, and F together, and divide the result by 1,000,000. Enter the result in Box 5.
    12. Add the values in Boxes 4 and 5 together, and enter the result in Box 6. This is the expected savings per year due to adding a radiant barrier or additional attic insulation.
    13. a. If you plan to install a radiant barrier
      Determine the estimated cost for installing a radiant barrier in your home. This may be from a quote, or you may estimate the cost by using the values in Table 1 along with your estimate of the ceiling area. Note that for radiant barriers installed on the rafters or on the roof deck, you will have to estimate the area of the roof and the areas of the gable ends. Enter the estimated cost in Box 7. b. If you plan to install additional attic insulation.
      Determine the estimated cost for installing more insulation in your home. This may be from a quote, or you may estimate the cost by using the values in Table 2 along with your estimate of the ceiling area. Enter the estimated cost in Box 7.
    14. Go to Table Z. Locate the census region where you live and read off the value for electricity. Enter this value in Box 8.
    15. Go to Table Z. Locate the census region where you live and read off the value for either electricity, oil, or natural gas, depending upon your heating fuel type. Enter this value in Box 9.
    16. Multiply the value in Box 4 by the value in Box 8. Enter the result in Box 10.
    17. Multiply the value in Box 5 by the value in Box 9. Enter the result in Box 11.
    18. Add the value in Box 10 to the value in Box 11 and enter the result in Box 12.
    19. Compare the value in Box 12 with the value in Box 7. If the value in Box 12 is greater than or equal to the value in Box 7, then the radiant barrier or additional insulation is an economical investment. If the value in Box 12 is less than the value in Box 7, then the radiant barrier or additional insulation is not an economical investment.
    20. A simple payback period may also be determined by dividing the value in Box 7 by the value in Box 6. The result will be the number of years that it takes for the energy savings with the radiant barrier or additional insulation to pay back its initial cost. Note that this procedure is not applicable to the radiant barrier on the attic floor, because the energy savings changes from year to year.
    Note: If you are planning to install a radiant barrier on the attic floor on top of the existing attic insulation, you should go through the worksheet twice, using the two factors that are given in Steps 8a and 9a to obtain an estimate of the expected range of energy savings.
    Example of Use of Worksheet
    I live in Orlando, Florida in a one-level 1800 square foot house. I have a heat pump system that has medium efficiency. My electricity costs 8 cents per kilowatt hour. I have 3.5 inches of fiberglass batt insulation (R-11) in my attic and the air-conditioning ducts are in the attic. A contractor has quoted a price for a radiant barrier installed on the bottoms of my rafters and on the gable ends for $400. Would this be a good investment?
    Following the steps outlined in the instructions, the worksheet is filled out. The total present value of energy savings given in Box 12 is $533.14. This value exceeds the quoted cost of the radiant barrier of $400, and thus this would be a good investment.




    EXAMPLE



    ENERGY SAVINGS ESTIMATE FOR RADIANT
    BARRIERS OR ATTIC INSULATION
    WORKSHEET
    COST OF ENERGY FOR HEATING AND COOLING
    Code: (A) (B) (C) (D) (E) (F)
    Cooling Equipment Efficiency
    (From Table X)
    Heating Equipment Efficiency
    (From Table X)
    Cooling Fuel Price
    $/Million BTU
    Heating Fuel Price
    $/Million BTU
    Cooling Energy Cost
    $/Million BTU
    [C÷A]
    Heating Energy Cost
    $/Million BTU
    [D÷B]
    2.6 1.9 8x2.93=
    23.44
    8x2.93=
    23.44
    9.02 12.34
    For fuel prices:
    Electricity: $/million BTU = ¢/KWH x 2.93
    Natural Gas: $/million BTU = ($/therm or $/CCF) x 10
    Fuel Oil: $/million BTU = $/gal. x 7.15


    ESTIMATED ENERGY SAVINGS
    Code: (1) (2) (3) (4) (5) (6) (7)
    Ceiling Area, Square Feet Cooling Load Factor
    (From Table Y)
    Heating Load Factor
    (From Table Y)
    Annual Cooling Savings, $/yr
    [(1) x (2) x E] ÷ 1,000,000
    Annual Heating Savings, $/yr
    [(1) x (3) x F]÷ 1,000,000
    Total Energy Savings, $/yr
    [(4)+(5)]
    Cost for RB or Insulation, $
    1800 2575x0.98=
    2524
    275x0.88=
    242
    40.98 5.38 46.36 400



    ESTIMATED LIFE CYCLE PRESENT VALUE SAVINGS

    Code: (8) (9) (10) (11) (12)
    Cooling Discount Factor
    (From Table Z)
    Heating Discount Factor
    (From Table Z)
    Present Value Cooling Savings, $
    [(4) x (8)]
    Present Value Heating Savings, $
    [(5) x (9)]
    Total Present Value Energy Savings, $
    [(10) + (11)]
    11.50 11.50 471.27 61.87 533.14

    Pros and Cons: Asphalt Roofing vs. Metal

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    Product Pros and Cons: Asphalt Roofing vs. Metal

    Asphalt shingles, such as these from CertainTeed, dominate new home construction and even the reroofing market because they are economical, easy to install, and last about 20 years. 
    Asphalt shingles, such as these from CertainTeed, dominate new home construction and even the reroofing market because they are economical, easy to install, and last about 20 years. 
    If you were to ask a sampling of production builders what is the best roofing material on the market, they're likely to tell you asphalt. The average residential architect, on the other hand, would probably say metal is the real deal. Heaven only knows what a home buyer or custom home client will choose—slate, clay, concrete—or if they'll even care.

    The roof is arguably the most important surface in a home, perhaps even more essential than the exterior walls. As the most exposed plane, the roof has a mammoth task. It's under constant assault from the sun and rain, and, if leaky, could result in thousands of dollars worth of direct repair as well as ancillary damage. Still, a roof is one of those things that many consumers don't think about until there is a blizzard, hail storm, or rainstorm.

    So what accounts for the discrepancy in material tastes? That builders, architects, and home buyers have opposing views of roofing material is telling, but their preferences speak to individual agendas as much as it speaks to the materials.

    Most home buyers, for example, care mostly about price and don't care as much about material as long as the roof functions properly and for the foreseeable future. Production builders care about looks and function, too, but affordability is top of mind. And architects want a roof to function well, but they are concerned that it be aesthetically pleasing.

    Naturally, the asphalt industry says its product is the best roofing you can buy. "Asphalt roofing is easy to find, easy to install, and easy to maintain," the Washington, D.C.-based Asphalt Roofing Manufacturers Association says. "It's also incredibly easy on the eye. And let's not forget, it's easy on the wallet, too!"

    Indeed, asphalt is easy to install and produces a decent-looking roof, but most architects and builders say the product is popular mainly because it's economical.

    Depending on the product line, shingles come with warranties lasting anywhere from 20 to 30 years, though builders in the field say the numbers are often shorter depending on the location of the country and maintenance.
    The asphalt roofing industry makes a good case for its product being No. 1 because its product is No. 1. Industry estimates claim four out of five roofs are covered with asphalt, though if you drive around most subdivisions—new or established—that number seems woefully low.

    Asphalt's market share notwithstanding, the metal people say their product is much better. According to the Metal Roofing Alliance in Belfair, Wash., "Longevity is one of the top reasons consumers report choosing metal roofing for their homes." The group says "metal roofing can last as long as 50 years or more, requiring very little maintenance and looking beautiful all the while."

    When HUD's Partnership for Advancing Technology in Housing launched the Concept Home program some years ago, the group's mission was to use the best available materials, products, and technology for the homes it builds. The group settled on metal roofing for its subsequent homes in Omaha, Neb., and Charleston, S.C., because of the looks and the longevity—benefits that architects often cite as their reason for choosing the material. They are mesmerized by the crisp, contemporary look; that it lasts forever is gravy.
    But longevity and good looks come with a very high price, one that turns off even ardent admirers of metal. "I use asphalt on all my projects," says Texas-based builder Robert Aiken. "Metal is a better roof, but it costs three times as much."

    So where does that leave you? The tradeoffs are not so simple. Both materials are versatile, offering a variety of looks. But is it enough to specify an asphalt roof that should last 20 years or more? Or is it worth it to pay three times as much for metal that could outlive the homeowner and the house? Considering how long the average home buyer stays in a house, the answer may be simple.
    Here's a handy guide that outlines the pros and cons of asphalt versus metal roofing. Use it to evaluate the options for your customers, and let us know what you use and why.

    Asphalt comes in basic three-tab products, but higher-end, laminate shingles are also available.
    Asphalt comes in basic three-tab products, but higher-end, laminate shingles are also available.

    Pros for Asphalt Shingles:

    An accepted and proven material that builders know and trust. There's a reason so many builders use the product, and it comes down to 100 years of service in the home building industry. Plus, home buyers are comfortable with it, which is extremely important.

    Economical. The low cost of asphalt is probably its biggest selling point. A basic three-tab shingle roof might set you back about $100 to $200 per square (or a 10-foot-by-10-foot area), making it ideally suited to production housing or to entry-level housing.

    Easy to work with and handle. Perhaps no other roofing product is as easy to install. In some cases, a house can be done in one day by professional contractors. Even serious DIYers have been known to tackle roofing projects, though it's highly recommended that they don't because of warranty issues.

    Easy to repair. As easy as asphalt is to install, it's equally easy to repair if it gets damaged.

    Style options. Asphalt comes in basic offerings for the cost-conscious, but it can be ordered in fancy styles that mimic wood shakes or slate. Basic three-tab shingles dominate the category, but thicker, high-end laminates are available in many colors and with deep shadow lines.

    Good performance record. Depending on the product line, asphalt shingles come with a 20- to 30-year warranty. Many are fire-rated (as high as Class A), and require minimal maintenance. Some manufacturers offer products that meet Energy Star requirements and qualify as a cool roof under federal standards, making them eligible for tax credits.

    Cons for Asphalt Shingles:


    Can be boring. Though snappy colors and styles are available, builders tend to select basic single-color products that have a tendency to look dull.

    Susceptible to severe weather. In general, asphalt provides good uplift protection, but the product does not hold up well to severe weather such as hail. The NAHB Research Center says wind- and impact-resistant shingles are available, but they cost about 50 percent more than conventional products. Moreover, asphalt roofs that do not get adequate sunlight can be vulnerable to moss, mildew, and algae, which can shorten lifespan.

    Longevity questions. Warranties on asphalt roofs are relatively high, but performance is closely tied to a well-ventilated roof deck and homeowner maintenance.

    Can be heavy. While basic shingles weigh about 200 pounds per square, some laminated, textured, and higher-end architectural shingles can clock in at close to 500 pounds per square.

    Nascent recycling. According to the Northeast Recycling Council, the U.S. manufactures and disposes of about 11 million tons of asphalt shingles per year. Most—about 10 million tons—is from installation scraps and tear-offs from re-roofing. Moreover, the group cites EPA studies that shingle waste makes up 8% of the total building-related waste stream. The asphalt recycling industry is still young, however, though manufacturers are developing ways to find uses for the material including pavement, new roofing, and road and ground cover, says the California Department of Resources Recycling and Recovery.

    Pros for Metal Roofing:

    Lightweight. Metal is about the lightest material you can install on your roof. Though weight varies based on type, contractors and manufacturers say aluminum varies from about 50 pounds per square, while steel can be anywhere from 100 pounds to 250 pounds per square, says MetalRoofingSource.com.

    Longevity. Metal offers good weather resistance and can last a long time. There are rumors of copper and zinc metal roofs in Europe lasting well over 100 years. Though this might be possible with care and maintenance, you can reasonably expect a metal roof to last about 60 years, give or take.

    Long warranty. Many metal manufacturers offer limited warranties that last up to 50 years.

    Stellar extreme-weather performance. Contractors say metal is excellent at preventing leaks, offers good wind resistance, and is fireproof. In fact, says the Metal Roofing Alliance, some insurance companies offer home buyers up to 30% reduction in premiums for weather-resistant metal roofs .

    Environmentally friendly. One of the most energy-efficient roofing materials, metal reflects heat and helps keep houses cooler in the summer. Plus, the product often contains high, recycled content and is itself recyclable.

    Cons for Metal Roofing:


    Very expensive. Metal's biggest drawback is the cost. Though manufacturers say prices have come down, metal, on average, costs three times as much as asphalt. Pricier metals such as stainless steel, copper, and zinc can cost way more.

    Can have a harsh appearance. Metal has a long history on barns and agricultural buildings, but for those who aren't familiar with this look, it can be harsh in a residential subdivision.
      Scotty, Scotts Contracting-- I have to chime in here: I don't agree with the Authors choice of words 'Harsh' "Metal Roofs come in every type of Designers Choice and Style and can mimic the "Look" of: Slate, Tile, Asphalt, etc.  They also come in every color in the Color Wheel and in some applications Custom Colors can be Ordered, with most manufacturers Guarantying the Color for 20 years.  The new metal roofing products when installed correctly can mimic any type of Asphalt Roofing materials; therefore, "A Home with a Metal Roof can blend in any Neighborhood".] 


      CLICK HERE to Email Scotty, with Scotts Contracting for any additional Comments, Questions, or for a Green Proposal for your next Roofing Project.

      Extreme expansion and contraction. Critics contend that some metal roofs expand and contract quite a bit, which compromises their long-term performance and their ability to remain water tight. This is often a function of the installation.

      Past failures and perception issues. Architects say there was a time when basic corrugated metal roofs corroded in 10 years or less. In some seaside applications, rust on some roofs is visible. Most products today, however, are made with alloys and specialized resin paints that can handle salt spray, extreme heat, and heavy precipitation without issue, the industry says.

      Product selection is important for good performance. Though high-performing materials such as stainless steel, copper, and zinc are available, low-end steel products are still available. Architects advise against low-grade metals that are thinner and less durable, especially near seaside locations.Article by: Nigel F. Maynard is a senior editor for Builder magazine.

      CLICK HERE to Email Scotty, with Scotts Contracting for any additional Comments, Questions, or for a Green Proposal for your next Roofing Project.scottscontracting@gmail.com

      • I have a local recycling source for Asphalt Shingles. 
      • Tamko- Roofing Supply Manufacturer I consider a Local Company (within 300 miles)
      --
      Scott's Contracting
      scottscontracting@gmail.com

      Build a Green St Louis!

      I'm trying to help my fellow stlouis neighbors from getting sick from nuclear radiation #BioRad Hazardous Waste Disposal eliminates toxic radiation in the soil. http://electrohemp.org Scotty, writes: Sustainable Buildings are the future of the Construction Industry and our future Energy needs will be met from true Clean Energy Sources as well as creating Net Zero Energy Efficient Buildings for a sustainable future. Design Build Contractor for the St Louis Region-Specializing in Energy Conservation Design Build Projects and Solar PV Clean Energy Systems

      Proud promoter of: Green, Eco Friendly, and Sustainable Building Products with Energy Reducing Resources and On-Site Solar PV Clean Energy Systems for the St Louis Region and beyond. Let us show you how: Green Building Doesn't Cost it Saves!

      Financing is available to include: Solar Systems, Solar Leases, Bank Loans, PACE financing, Energy Conservation, Weatherization are available.

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