New Title 24 Standards For Lighting Windows And Ventilation

Download New Title 24 Standards For Lighting Windows And Ventilation

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<ul><li>1.Lighting, Windows &amp;Ventilation California Title 24 StandardsPrepared by Douglas Beaman Associates </li></ul><p>2. Windows, Lighting &amp; VentilationCalifornia Title 24 StandardsTable of Contents 1 Introduction and Window Basics 2 Lighting Basics 3 Indoor Air Quality and MechanicalVentilationCopyright 2009Douglas Beaman Associates 3. California Center for Sustainable Energy Wi d Windows, Li hti dLighting and Ventilation Welcome and Window Basics Welcome and Window Basics Page 2 Introduction and Window Basics Page 1 4. California Center for Sustainable Energy Presenters:Douglas Beaman, Gary Wollin608 - 13th Street Modesto, California 95354doug@dougbeaman.comgary@dougbeaman.com (209) 524-1000Welcome and Window Basics Page 3January 1, 2010 Any building permit applied for on or after January 1 1, 2010 must comply with the new Standards. Welcome and Window Basics Page 4 Introduction and Window Basics Page 2 5. California Center for Sustainable Energy Available in PDF format fromthe CEC website: Publication #:CEC-400-2008-001-CMF The Standards contain theactual code language,harder to understandunderstand,but the last word. www.energy.ca.gov/title-24 Welcome and Window Basics Page 5 Available in PDF format from the CEC website: Publication #:CEC-400-2008-016-CMF Designed to be used by building departments, builders, builders energy consultants.www.energy.ca.gov/title24 Welcome and Window Basics Page 6 Introduction and Window Basics Page 3 6. California Center for Sustainable Energy Welcome and Window Basics Page 7 The word fenestration finds its root in the Latin word for window, fenestra. Architecture Products that fill openings in a building envelope, suchas windows, doors, skylights, curtain walls, etc.,designed to permit the passage of air, light, vehicles,or people. lWelcome and Window Basics Page 8 Introduction and Window Basics Page 4 7. California Center for Sustainable Energy Almost no homes enjoyed the benefits of insulation. Homes either had mass, stone walls, sod or logs, were timber ll d li b framed with possibly some straw or mud in the voids. For many glass was an expensive luxury. Well into the 19th century glass was expensive and many homes had double shutters. Homes were naturally ventilated. Summer and Winter. Welcome and Window BasicsPage 9 Homes for millennia had heating that was provided by a fireplace. In f t th E gli h I fact the English word for window does not come from a dfi d d tf hole in a wall but a hole in the roof that the Vikings used to allow the smoke out of a building. Origin:11751225; Middle English windoge, windowe Old Norse vindauga equiv to vindr = wind + auga = eyevindauga, equiv. Welcome and Window Basics Page 10 Introduction and Window BasicsPage 5 8. California Center for Sustainable Energy Window glass, in use since the 1st century AD, was originally made bycasting, or by blowing hollow cylinders that were slit and flattenedinto sheets sheets. The term glass developed in the late Roman Empire. It was in theRoman glassmaking center at Trier, now in modern Germany, thatthe late-Latin term glesum originated, probably from a Germanicword for a transparent, lustrous substance. Welcome and Window Basics Page 11 The crown process was a later technique, in which a gather ofglass was blown and shaped into a flattened globe or crown.TheTh pontil rod was attached to the flat side, the blowpipeil d h d h flid h bliremoved. By spinning the reheated crown on the rod, thehole left by the blowpipe enlarged, and eventually the disk,through centrifugal force, flapped out in a large circularsheet. The pontil rod was cracked off, leaving a scar, orbull's-eye. Welcome and Window Basics Page 12 Introduction and Window BasicsPage 6 9. California Center for Sustainable Energy 1834, Robert Lucas Chance introduced "Improved Cylinder Sheet" glass which was produced using a process invented in Germany. This produced even finer and larger glasses. This was the glass used to glaze the "Crystal Palace" in London. Welcome and Window Basics Page 13 Today, nearly all window glass is made mechanically by drawing g y g glass upward from a molten p ppool fed from a tank furnace. In the Fourcault process the glass sheet is drawnthrough a slotted refractory block submerged inthe surface of the glass pool, into a verticalannealing furnace from which it emerges to becut into sheets. Welcome and Window Basics Page 14 Introduction and Window BasicsPage 7 10. California Center for Sustainable Energy The new glass provides a vacuum space between two panes of glass. Tokeep the two sheets of glass from being drawn together by the vacuum,low thermal-conductivity spacers are placed in the space between thetwo panes. (These are the small dots that can be seen in thephotograph.) The vacuum is only about 1/100th as strong as what is typically found in anordinary thermos, it is still far better thanstandard double pane glass in preventingheat loss from conduction and fromconvection. The only other glazing systemsI have come across with close to this level ofinsulation value have been nanogel-filledwindows, but those are just translucent,and do not allow clear vision through theglass.Welcome and Window BasicsPage 15 U-Factor SHGC (Solar SHGC(Solar Heat Gain Coeffieicnt) AL(Air Leakage) VTVisible Light Transmittance Welcome and Window BasicsPage 16 Introduction and Window Basics Page 8 11. California Center for Sustainable Energy A measure of the rate of non-solar heat flow through amaterial or assembly. The lower the U-factor, thegreater a windows resistance to heat flow and thebetter its insulating value. The U-factor is thereciprocal of the R-value (U=1/R). Welcome and Window Basics Page 17 The fraction of solar radiation transmitted through a window, expressed as a percentage. The lower a window s SHGC, windows SHGC the less solar heat it transmits and the greater its shading ability. Generally, a lower SHGC is desirable in warm climates, and a higher SHGC in cold ones. Welcome and Window Basics Page 18 Introduction and Window BasicsPage 9 12. California Center for Sustainable Energy Heat loss and gain occur by infiltration through cracks in the window assembly. It is indicated by y y an air leakage rating (AL) expressed as the equivalent cubic feet of air passing through a square foot of window area. The lower the AL, the less air will pass through cracks in the window assembly. assembly At this time, the AL is optional. timeoptional Select windows with an AL of 0.30 or less (units are cfm/sq ft).Welcome and Window Basics Page 19 The visible transmittance (VT) is an optical property that indicates the amount of visible light transmitted. transmitted The NFRC's VT is a whole window rating and includes the impact of the frame which does not transmit any visible light. While VT theoretically varies between 0 and 1, most values are between 0.3 and 0.8. The higher the VT, the more light is transmitted. A high VT is desirable t d i bl to maximize d light i i daylight.Welcome and Window Basics Page 20 Introduction and Window BasicsPage 10 13. California Center for Sustainable Energy Welcome and Window Basics 21 An Insulating Glass Unit is the transparent component of a window or door assembly. An IGUpy comprises two or three panes of glass separated with spacers and sealed at the edges. IGU also includes the insulating air space between the panes. Often this air space is replaced with a gas-fill. gas fillWelcome and Window Basics Page 22 Introduction and Window BasicsPage 11 14. California Center for Sustainable Energy Welcome and Window Basics Page 23 Welcome and Window Basics Page 24 Introduction and Window BasicsPage 12 15. California Center for Sustainable Energy Single-Glazed with Clear Glass Relative to all other glazingoptions, single-glazed withclear glass allows thehighest transfer of energy(i.e. heat loss or heat gaindepending on local climatepgconditions) while permittingthe highest daylighttransmission.Welcome and Window Basics Page 25 Originally, the space was filled with air or flushed with dry nitrogen just prior to sealing. In a sealed glass insulating unit, air currents between the two panes of glazing carry heat tothe top of the unit and settle into cold pools at the bottom. Filling the space with a lessconductive, more viscous, or slow-moving gas minimizes the convection currents withinthe space, conduction through the gas is reduced, and the overall transfer of heatbetween the inside and outside is reduced. Argon is inexpensive, nontoxic, nonreactive, clear, and odorless. The optimal spacing for an argon-filled unit is the same as for air, about 1/2 inch (11-13 mm). Krypton has better thermal performance, but is more expensive to produce. Krypton is particularly useful when the space between glazings must be thinner than normally desired, for example, 1/4 inch (6 mm). The optimum gap width for krypton is 3/8" 3/8 (9mm). A mixture of krypton and argon gases is also used as a compromise between thermal performance and cost. Welcome and Window Basics Page 26 Introduction and Window BasicsPage 13 16. California Center for Sustainable Energy Low-emittance (Low-E) coating are microscopically thin, virtually invisible,metal or metallic oxide layers deposited on a window or skylight glazingsurface primarily to reduce the U-factor by suppressing radiative heatU factorflow. The principal mechanism of heat transfer in multilayer glazing is thermalradiation from a warm pane of glass to a cooler pane. Coating a glasssurface with a low-emittance material and facing that coating into thegap between the glass layers blocks a significant amount of this radiantheat transfer, thus lowering the total heat flow through the window. Low-E coatings are transparent to visible light. Different types of Low-Ecoatings have been designed to allow for high solar gain, moderatesolar gain, or low solar gain.Welcome and Window BasicsPage 27 One approach to reducing heat loss has been to replace the aluminum spacer with a metal that is less conductive, e.g. stainless steel, and change the cross-sectional shape of the spacer. Another approach is to replace the metal with a design that uses materials that are better insulating. The most commonly used design incorporates spacer, sealer, and desiccant in a thermoplastic compound that contains a blend of desiccant materials and incorporates a thin, fluted metal shim of aluminum or stainless steel. Another approach uses an insulating silicone foam spacer that incorporates a desiccant and has a high-strength adhesive at its edges to bond to glass. The foam is backed with a secondary sealant. Both extruded vinyl and fiberglass spacers have also been used in place of metal designs. For purposes of determining the overall window U-factor, the edge spacer has an effect thatextends beyond the physical size of the spacer to a band about 2-1/2 inches wide. Thecontribution of this 2-1/2-inch-wide "glass edge" to the total window U-factor dependson the size of the window. Glass edge effects are more important for smaller windows,which have a proportionately larger glass edge area. Welcome and Window BasicsPage 28 Introduction and Window Basics Page 14 17. California Center for Sustainable Energy Back to California Welcome and Window Basics Page 29 151(f)3 and 4 have the prescriptive requirements for fenestration in low-rise residential buildings. These include requirements for maximum glazing area, maximum U-factor, and for some climate zones, a maximum SHGC requirement. Welcome and Window Basics Page 30 Introduction and Window BasicsPage 15 18. California Center for Sustainable Energy Welcome and Window Basics Page 31 Window values: U-factors from 0.55 0.67 to 0.40 Welcome and Window Basics Page 32 Introduction and Window BasicsPage 16 19. California Center for Sustainable Energy 151(f)3 Exception allows up to 3 square feet of the glazing installed in doors and up to 2 square feet of tubular skylight with dual-pane diffusers to have an assumed U-factor equivalent to the Package requirements. Welcome and Window Basics Page 33Type 1 Manufactured products are delivered pre-assembled pre assembled from the factory. This is the most common type of fenestration inresidential construction. Welcome and Window Basics Page 34 Introduction and Window BasicsPage 17 20. California Center for Sustainable Energy Type 2 Site built Site-built products are glazed or assembled on siteusing factory prepared systems. . . . For unlabeledsite-built fenestration use default values fromStandards Table 116-A for U-factor and Table 116-Bfor SHGC, otherwise, select site-build fenestrationfrom NFRCs Certified Products DirectoryNFRC s Directory. See http://www.NFRC.org. Welcome and Window Basics Page 35 Type 3 Field fabricated Field-fabricated products are built on site usingstandard dimensional lumber or other materials notintentionally prepared for use as a fenestrationproduct. For field-fabricated fenestration use defaultvalues from Standards Table 116-A for U-factor andTable 116-B for SHGC116 BSHGC. Welcome and Window Basics Page 36 Introduction and Window BasicsPage 18 21. California Center for Sustainable Energy Welcome and Window Basics Page 37 Answer For glass block, use the U-factor and SHGC values from Standards Tables 116-A and 116-B for the frame type in which the gypglass blocks are installed. The worst-case scenario would be a metal-framed glass. The U-factor for metal framed glass block is from Table 116-A is therefore0.87. The SHGC depends on whether the glass block has a metal or non-metalframe, and is operable or fixed or clear or tinted. For this example, the glass block is operable and clear, therefore the S GC fSHGC is 0.70. Glass block is considered a field-fabricated product and therefore does notneed a label. Welcome and Window Basics Page 38 Introduction and Window BasicsPage 19 22. California Center for Sustainable Energy Welcome and Window Basics Page 39 Welcome and Window Basics Page 40 Introduction and Window BasicsPage 20 23. California Center for Sustainable Energy Doors with less than 50% glass areas are treated as a door with fenestration installed within the door. The glass area is calculated as the sum of the glass areas plus two inches on all sides (to account for framing). Welcome and Window Basics Page 41 The NFRC label if one is available, or The default values from Standards Table 116-A and 116-B. The opaque part of the door is ignored in the prescriptive approach. If the performance approach is used for the glazing part of the door, an NFRC label or default values for U-factors and SHGC must be used, for the opaque portion of the door, a default value of 0.50 must be assumed. assumed Alternatively, if available, NFRC values for U-factor and SHGC may be used for the entire door, including the opaque areas.Welcome and Window Basics Page 42 Introduction and Window BasicsPage 21 24. California Center for Sustainable Energy I plan on installing a tubular skylight using the performance approa...</p>

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