Glass u value chart. Hot southern climates need only a 0.
- Glass u value chart Clear 6. 20 to 1. 5 1. 7 The shaded boxes Feb 5, 2024 · How are U-Values for windows calculated? Calculating U-values can seem complex, but it is really quite simple. 19/. To calculate U-value, divide 1 by the R-value—a 3. 1 applies to windows (and rooflights) with wood or plastic frames. INSULATED LOW E GLASS UNITS SHGC S C U Value LOW E GLASS: Glass which has a Low E (Emissivity) coating provides greater insulation by reflecting the a building in comparison to 3mm Clear glass. Impact-rated IG's will have a pane of glass that is approximately 0. When applied to building components such as windows, the lower the U-value, the greater the energy efficiency. The higher the R-value, the greater the insulating power. High • U-Values are quoted in W/m2/K, rounded down to the nearest 0. Refl. 23/. Please see the charts below for each product's specific U-Values: Energy Star Qualification Chart – All Glass Handling and Safety Guide . It is NOT a measurement of the rest of the window, and does not reflect the thermal efficiency of the frame and other window components. Example: A 2-inch concrete insulating block has a U-value of U-0. 25. 1 2. 12 10. It measures the insulation efficiency across the material’s thickness, unlike U-values which indicate heat loss. The higher the U-Value, the more heat leaves the house via the system. For data on: Solargreen® Glass — see AtlanticaTM Glass Solex® Glass — see SolexiaTM Glass Azurlite® Glass — see AzuriaTM Glass Each pane of glass is typically 0. K) A measure of the air-to-air heat transfer due to thermal conductance and the difference in indoor and outdoor temperatures. These could include thermal pressure plates in a curtain wall or warm edge spacers in glass units. Where (#2) appears, this identifies the glass’ coated surface that is glazed to the inside of a building or the inside of a ThermoTech unit. 20 1. Northern North-Central South-Central: Low U-Factor Medium Solar Single glazing U value = 5. 73 30. U-Factor Describes the resistance of the door glass to conducting heat and cold through the unit. 0 simulations. It can range in value Values are averages for use as design guides, and were obtained from several guarded hot box tests (ASTM Standard C1363) on hollow-backed types and types made using backing of wood fiber, foamed plastic, and glass fiber. By filtering by Visible Light Transmission, Solar Heat Gain, Reflectance and U-Value you can… Learn the difference between R-value and U-factor ratings is how they are measured. A leader in tools for the glass industry. It is determined by dividing the U-factor into 1, (R-value = 1/U-factor). Indicative U values for windows with wood or PVC-U frames εn is the emissivity of the low E glass. Start now. Glass Type Emissivity (low‐e) U‐Value* (air) U‐Value* (argon) Clear 0. com specification section 088000 | us. Enter the details of your project into our Thermal Calculator and measure thermal performance for any system, solar heat gain and visible light transmittance in less than 60 seconds. 8 operated by Lawrence Berkeley National Laboratory (LBNL) using International Glazing Database (IGDB) v102. All performance for C. 5 0. 6 w/m2K. 78 20. BTU/ ft. 27 . 90 . 20 and an R-value of R-5. (3) Comfort Indoor Glass Temperatures are for the center portion of the glass. U-value is sometimes known as thermal transmittance. In Trans. 78 15. 030" interlayer) 08 glass: Same as 04, with white interlayer 99 93 glass: Same as 05, with i89 coating on interior surface 05 glass: Tempered over tempered VS Tested Performance Information Performance documents for altitude limits, NFRC ratings, center of glass, joining window load table, air infiltration, and more. Whereas the U-value measures how good a window is at preventing heat loss, and Energy Rating takes numerous factors into account – such as G-value and L-factor – to give a window an overall energy efficiency score. Choosing the wrong U-factor for your climate can lead to inefficiency and high utility bills. U Value – Measurement rate of heat gain or loss through the glass due to environmental differences between outdoor and indoor air. Noise Reduction Solution Charts Use the following product selection tool to find specific glass products by their performance statistics. 08 04 glass: Tempered over laminated HS (0. 125". 5?? w/m2K. 1 (800) 929-3667 (Door) Low E Insulated Glass. Those quoted are normal emissivities – uncoated glass is assumed to have a normal emissivity of 0. The lower the number, the better May 13, 2024 · The higher the VT rating (value from 0 to 1), the more light the glass lets into the home. Finding the U-factor of our systems is simple and has never been more accessible. Double glazing with low emissivity glass (with air cavity) U value = 1. Note: Measurement of improved U-values are calculated using a baseline of a Double Low-e 1” IGU Solarban ® 70 (2) Clear + Clear with argon from Vitro Architectural Glass, with a U-value of 0. sg Testing 18/08/2020 27/05/2022 calculator , Glass , shading coefficient , shgc , u-value 0 Comment Related services Glass optical & thermal properties. U Value Calculator: Please choose the depth of foam glass that can be put down - 150, 200, 250 or 300mm Glass Only performance data for our Full range of Glass Products. The size of the piece is also important when it comes to determining its value: The larger the sea glass, the more valuable it is; The smaller the glass, the lower the value. But what is a U-value? And, for that matter, what are G-values and L-values, and why are they important? U-values explained. 38mm grey 41 5 5 0. R-VALUE R-value is a measure of heat flow resistance. Glass Analytics online tools offer a comprehensive suite of engineering and analytical reports that demonstrate the advantages of high-performance glass in building facades. Keeps the view while beating the heat. It is more A leader in tools for the glass industry. The center-of-glass is the Understanding How Size Affects Sea Glass Value Size affects sea glass value. Compare insulation R-values before you buy. ” In other words, a u-value is used to measure how well or how badly a building component transmits heat from the inside to the outside. One-inch insulating glass data and comparisons can be found at www. 45 R-value equals a U-value of 0. 6 w/m2K (Watts / square metre Kelvin). spacer. The lower the number the better performance. For more information about Solarban® 60 low-e glass and other Cradle to Cradle Certified® architectural glasses by Vitro Glass, visit vitroglazings. 34 . 74 25. without edge effects, and expresses the steady-state density of heat transfer rate per temperature difference between the environmental temperatures on each side. The lower the number is, the better the insulating qualities of the glass. Join as we dive deeper to understand the differences and why this is important for both commercial and residential properties. Values are center of glass calculated using LBNL Window 7 per NFRC100 conditions. 7 2. 28: Jun 8, 2022 · Difference Between U-Value and Window Energy Rating. calculate U-Factor:-Center-of-glass (COG) Typical value 0. Values for each contribution by: U0 = (Uc 9·Acg + Ue ·Ae9 + U(A1) I (Acg + Aeg + A1) , (2) where the subscripts cg, eg, and f refer to, respectively, the center-of-glass, edge of-glass and frame. 5 85 8 8 65 7 <1 5. May 6, 2020 · A measure of heat gain or heat loss through glass due to the thermal conductance and the difference in indoor and outdoor temperatures. 5 Exterior tint may vary from unit to unit. 32 . Quick Summary:At a quick glance - the U-value is the measure of how well a material resists heat flow. (5) UV Damage Weighted Transmittance (Tdw) is the weighted average for wavelengths 300 - 700 nm (based on CIE 89/3). how easily heat gets through windows and doors. National Processing Capabilities . 4 %âãÏÓ 2265 0 obj > endobj xref 2265 31 0000000016 00000 n 0000002149 00000 n 0000002496 00000 n 0000002643 00000 n 0000003095 00000 n 0000004072 00000 n 0000004123 00000 n 0000004162 00000 n 0000010342 00000 n 0000010947 00000 n 0000011348 00000 n 0000011784 00000 n 0000011863 00000 n 0000012455 00000 n 0000012511 00000 n Oct 31, 2024 · To calculate R-value, divide 1 by the U-value figure. The lower the U-Value rating of the aluminium window, the more efficiently it insulates heat loss / gain. U value is typically measured in Watts per square metre Kelvin or W/m2K. The SHGC measures how much of the sun’s heat comes through the window. Glass 1 Glass 2 Cavity Fill Cavity Width (mm) 6 8 10 12 14 16 18 20 Clear Clear Air 3. (4) The UV Transmittance is determined as an average for wavelengths 310 -380 nm. 2 applies to windows with metal frames, Framing, cladding, frame type and other items will affect the overall thermal values of a complete window. 0 2. For example, a U-value of 0. 15 12. e. 0 chen. 20 . Find out why in the seller's fact sheet on R-values. annealed glass can be cut, machined, drilled, edged and polished. U-factors of windows will generally fall between . 02/. Because Low-E glass improves (lowers) the IG unit U-Value, using Low-E glass will increase the unit’s interior glass surface temperature. 1. 6 Clear Hardcoat low-E Air 2. 2 and 1. 7 Clear Hardcoat What is a U Value? U Value is A measure of air-to-air heat transmittance (loss or gain) due to thermal conductance and the difference in indoor and outdoor temperatures. 1 1. Center-of-glass coefficient Center-of-glass U-Values are calcu Nov 18, 2020 · Therefore, R-Value multiplied by U-Value always equals 1. To calculate a U-value, the heat transference rate is divided by the temperature difference on either Jun 27, 2019 · What is the best R-value for windows and doors? Improved education and awareness of the cost of heating and cooling that escapes from poorly insulated components and glass panes have led to window and door manufacturers developing energy efficient windows and doors typically labeled "R5 U. 15 1. The lower the U-Factor, the better the window insulates. Transmittance and reflectance values based on spectrophotometric measurements and energy distribution of solar radiation. com and center of glass U‐values for various Vitro glass products. 3 2. single glass performance values vlt visible light transmission vlr visible light reflectance vlri visible light reflectance shgc u-value colour and type % external % internal % w/m2k tinted pvb continued 8. 2" meaning the glass is the most energy efficient possible at a "5" rating and the window or door with all What is a U-Value? “U-value is the measure of the overall rate of heat transfer through a particular section of construction. The lower the U-value, the better the insulation. Thermal transmittance, called U-value, is the amount of thermal energy, measured in W (Watts) flowing through one m² (square meter) of a building component like a window, door, wall, or other part of the building structure if the temperature difference between both sides of the component amounts to 1 K (Kelvin), The unit of measurement is W/m²K. 52mm grey 43 5 5 0. This can improve Is the glazing parameter that characterizes the heat transfer through the central part of the glazing, i. lSee assembly. 030, we get an R-Value for the window of 3. The lower the U-value the better the insulation %PDF-1. 5 85 8 8 64 6 <1 5. 8 1. Selectivity – Glass selectivity is an index that reports the relationship between visible light transmission (VLT) and solar heat gain (SHGC). The latter also offers three opportunities to include a Low-E coating, versus only two on dual-pane glass. Calculating the U-factor of Kawneer systems has never been easier. 7 10. 26/. The lower the U-value the better insulation performance of the unit, which is why our customers often want lower U-values, because they are proof of better performing products. Variations and Strategies for Improving U-Value. Double glazing (with air cavity) U value = 2. Out Refl. U-values are measured in w/m2K which is the units of watts per square metre per degree Kelvin or in other words the amount of heat loss through a 1 square metre of material for every Heat loss is quantified by the thermal transmittance or U-value (U). Calculating u value of glass is simple. New Fineo vacuum insulated double-glazing has a U-value of just 0. Determining the U-Values of the glass and complying with the National Energy Act may be easier than you think. Typical value 0. ppgideascapes. How are U Values Calculated? Once you are familiar with what is u value, the second question arises about how u values are calculated. 64 0. Actual values may vary due to production tolerances. This performance data is not a commitment for Cardinal to produce. R means resistance to heat fl ow. 30. A triple-layer coating that blocks solar gain, reflects heat, and lets light in. 8 2. The overall U-Value is l')Stimated using area-weighted U. 6 2. 18/. over laminated temp. Table of U-Values . 5% more energy efficient than triple glazing. (0. com May 27, 2022 · A user-fiendly online glass U-value, SHGC & shading coefficient calculator, for single, double or triple glazing systems, developed by OTM Solutions Pte Ltd A U value is essentially the inverse of the thermal resistance of an element, and is defined as the steady-state density of heat transfer as a rate per degree Kelvin temperature difference between the environmental temperatures on either side. 7 — that’s 12. Just because a unit is triple glazed, it 2. Double glazing (with argon gas cavity) U value = 2. It is measured in watts over m2 per degree Celsius (w/m2°C). 0. 31/. G U- and R-values are based on ASHREA Winter Conditions. 25 or lower. 21/. How Is U-Value Determined? The U-Value of glass is the same as the U-Factor. Assemblies with lower U-Values transmit less heat than those with higher values. 837 (default) VIRIDIAN GLASS GUIDE™: GLASS PERFORMANCE - SINGLE GLAZING Product Name Nominal Thickness Visible Solar UV Trans U Value SHGC Weight kg/m2 Selectivity Trans. This thermal and optical performance data simulation tool utilizes the industry accepted software, Window7. 48/. Consult the product U-Factor charts to see how they will affect the overall system U-Factor. Pella manufacturers stipulate that ratings conform to applicable NFRC procedures for determining whole product performance. A number which describes, in specific terms, the ability of a material or assembly to transmit heat from outside to inside surfaces. If we do our reciprocal calculation using a U-Value of . ENERGY STAR does not consider center-of In this section, we will explore the difference between two of the most significant glass performance measures; U-Value and R-Value. Nov 14, 2017 · The quick response is as follows: ¼” (6mm) laminated glass has an approximate winter nighttime U-Value of 1. Laminated glass is a safety glass product and can be used in insulating (double U-factor is the rate at which a window, door, or skylight transmits non-solar heat flow. 3333. Framing, cladding, frame type and other items will affect the overall thermal values of a complete window. (centre of glass) ratings are based on Vision v4. The U-value, usually expressed in S. Thus an additional benefit of using Low-E glass is that it permits a higher relative humidity in a room before condensation will occur. Click here to view the declaration of conformity to EN 673: 2011 for U-values. U-Value. Warmly welcome to cooperate and develop with us! we architectural glass performance data and comparisons energy select | solarshield | stopsol 888-234-8380 | 800-251-0441 | info@us. Now, in the above-noted code requirements, we had a window U-value requirement of 0. Argon fill is 90% and air fill is 100%. 29 BTU/ ft. The U-value will be the same for that glass regardless of the window the glass is in. 25, while triple-pane windows may have U-values around . O. 02 while a 1” (25mm) insulating glass unit made with clear glass and with no coatings of any kind has an approximate winter nighttime U-Value 0f . 4 Values are based on comparison of Renewal by Andersen® double-hung window U-factor to the U-factor for clear dual pane glass non-metal frame default values from the 2006, 2009, 2012, 2015 and 2018 International Energy Conservation Code "Glazed Fenestration" Default Tables. In layman’s language, the lower u value, the better the thermal performance of the glass. "U" Value. U-Values range anywhere from 0. 12 8. If you are not sure, please use the following recommended emissivity values: Uncoated surfaces: 0. 3mm Clear 0. Misunderstanding 1:Thicker glass has much better U value than thin glass, laminated glass U value is significantly lower than that of the same thickness glass. 3 3. Solar Heat Gain Coefficient (SHGC): A measurement of the sun's heat energy that passes through the glass. So called 'Low-emissivity' or 'Low E' glass offers improved thermal insulation denoted by very low U-values. 65 0. U Value: the total heat transfer out of a window (Btu/hr-sq ft-F or W/sq m- C). Table 6. Namely, you have to divide 1 by U-value to get R-value. The lower the value (from 0 A large amount of glazing configurations means the perfect glass can be yours. and the IG unit thermal transmittance (U-Value). CALCULATING U VALUES for center of glass, edge of glass and frame performance. For windows, skylights, and glass doors, a U-factor may refer to just the glass or glazing alone. com, or call 1-855-VTRO-GLS (887-6457). Read This Before You Buy What you should know about R-Values The chart shows the R-value of this insulation. • For multi cavity and low-E combinations please contact Customer Services. Triple-pane glass features one additional pane of glass and one additional argon-gas blend filled air space. 27 1. 29. 61 5. fz@otm. 6 11. This coating option provides better protection against radiant heat transfer than single layer metallic Low E coatings. The overall IGU U-factor can be determined using the EOG and COG values and will be affected by the IGU make-up, including spacer type, IGU gas fill type, coatings, overall thickness, etc. 2 Nominal thickness – the glass thickness or the makeup of a ThermoTech unit. The lower the U-Value is, the less heat escapes through the window. 38mm bronze 50 5 5 0. 3. 48 0. 60 5. Shading Coefficient (SC): A measurement of the heat gain through the glass compared to a single lite of clear 1/8" glass. Double glazing with low emissivity glass (with argon gas cavity) U value = 1. G. Insulating Glass Unit Performance for 1-inch (25 mm) units with 1/2-inch (13 mm) airspace and two 1/4-inch (6 mm) lites Glass Type Outdoor Lite: Indoor Lite: Coating if Any + Coating if Any (Surface) Glass (Surface) Glass Visible Light Transmittance (VLT)2 % Visible Light Reflectance 2 (Btu/hr•ft2•˚F) NFRC U-Value 3 Solar Heat Gain At Energlaze we specialise in providing glazing solutions to increase the comfort of your home and lower your heating bills. 2-hr-°F (thermal break) Frame U-Factor includes heat transfer through surfaces perpendicular . These values are available for all Vantage aluminum windows and aluminium door products as part of their WERS rating. The lower the u-value the more restrictive the fenestration product is to heat transfer; reciprocal of r-value. 0476. Please see the charts below for each product's specific U-Values: Energy Star Qualification Chart – All Glass construction: Dual-pane glass has two panes of glass with an argon-gas blend in between for added insulation. Large pieces of sea glass (more than an inch in diameter) are tough to come by. 38mm grey 42 5 5 0. The lower the value, the greater is the insulating value. 2-hr-°F (aluminum spacer)-Frame. It is expressed as Watts per square metre Kelvin W/m2 K. 2-hr-°F (low-e IG)-Edge of Glass (EOG) Typical value 0. 3800-3900 Series Glass Package IG Thick Interior Glass Exterior Glass U-Value SHGC VLT U-Value SHGC VLT Clear 3/4" 2. May 20, 2015 · Glass type; U-value is an inverse measure; the lower the U-factor, the better insulated the window. The May 27, 2022 · The U-value, SHGC and shading coefficient of a glass is strongly dependent on the glass surface emissivity. • Argon figures are based on a standard 90% fill. What you need to do is determine the U-Value in relation to your relevant fixtures, and estimate their cost in relation to We goal to create much more worth for our customers with our rich resources, state-of-the-art machinery, experienced workers and exceptional providers for Laminated Glass U Value Chart, Tinted Tempered Glass Panels, Tempered Glass 1/2, Toughened Clear Glass,Curtain Wall Glass Specifications. Read more about the tools below In cold climates, the best U-factor is anything at or lower than 0. 7 Clear Clear Argon 3. So we take our R-Value of 21 and divide one by that number, and we get a U-Value of . 67 5. Cardinal's LoĒ³-366 glass is the new standard in energy efficiency. The lower the number the better the glass. 5 87 8 8 71 7 <1 5. 10). Performance Comparisons for Insulated Glass One Inch Insulating Glass Unit Comparisons with PPG Architectural Glass Total Total Winter Summer Shading Solar Light to Ultra Solar Visable Solar Night Day- Coeffi- Heat Gain Solar Glass Type Violet Visable Energy Light Energy time Time cient Coeffi- Gain % % % % % cient (LSG) Sungate ® 500 Low-E Glass Note: Measurement of improved U-values are calculated using a baseline of a Double Low-e 1” IGU Solarban ® 70 (2) Clear + Clear 1” with argon from Vitro Architectural Glass, with a U-value of 0. Aug 28, 2019 · For opening glass walls, the U-Value measures the heat that escapes from inside of the house, through the glass wall system, to the outside. Glass Designs 6'8" Height Doors Glass Size (Inches) 22x64 20x64 16x64 14x64 22x47 22x36* 20x36 22x27 8x36*16x40 8x42R 22x10A 22x10R 22x6 7x18 8x67x64 8x47 8x44S Decorative Glass 1. com or by calling PPG at 1-888-774-4332. 47 0. Mar 11, 2021 · Insulating glass unit (IGU) manufacturers report the overall, center-of-glass (COG), and edge-of-glass (EOG) U-factors for the IGU. 38mm green 68 6 6 0. As the u-value decreases, so does the amount of heat that is transferred through the glazing material. 47. Departures of ±50% or more from these values may occur. The lower the U-value the better the thermal performance of the glass. 6 0. 840 0. As you can see, U-value is the inverse of the R-value. Choosing windows with low U-values will also help to reduce your carbon footprint. The U-value of a window is a measurement of the rate of heat loss indicating how well your windows are keeping valuable heat in. 45 U-Value. 4 float glass (also called “flat” glass) that has not been heat-strengthened or tempered is annealed glass. 750" to 0. 7 0. 62 5. agc. Values include; Colour, Visible Light Transmittance and Reflections, UV Blockage, U-Value, SHGC, Selectivity ratio, Acoustics and Weight: Aug 18, 2020 · Online glass U-value, SHGC & shading coefficient calculator: V2. 8 w/m2K. Here is how it works: Thermal resistance, or the R-value, indicates how well a material holds onto heat. Low U-Factor High Solar Heat Gain: Low E2: Features a double layer of silver on an inside surface of IG glass. Full details about calculating the U-value of a window or door are given in BS EN ISO 10077-1. 090" interlayer) 10 glass: Temp. A U-value is a means of measuring ‘thermal transmittance’, i. 125" thick, so the air gap for a 1" IG with two panes of glass will be approximately 0. 1 Product name – refer to product for more information. 760". NFRC U-factor ratings, however, represent the entire window performance, including frame and spacer material. In warmer climates A higher U-value means there is more heat transfer and a low U-value is less heat transfer which means a higher insulated structure. to the glass plane. 9 1. units (Système Internationale d’Unités) of W/m²K, is the heat flux density through a given structure divided by the difference in environmental temperatures on either side of the structure in steady state conditions. U-VALUE The U-value is the measure of how much heat is transferred through the window. 6 10. 57 0. 89 The gas mixture is assumed to consist of 90% argon and 10% air Alternatively, specify Pilkington Insulight™ Therm 1. 20. All C. I. See full list on vitroglazings. A higher R-value indicates better insulating properties of U-Factor and the Solar Heat Gain Coefficient (SGHC). Energy Efficiency Content TBC. To convert U-value to R-value, you will need this key U-factor to R-value formula: R-Value = 1 / U-Value. 5 U Value. 08 In this case, you can use different components that are not specifically called for to meet the U-Factor specification. It provides year round performance and comfort. Glasscraft U-values The U-value of a sealed unit is determined by the elements that are used to make up the sealed unit. 24. While the U-Factor can take any value, in general for windows it ranges from 0. 3mm Clear 2. 7 1. 58 Numbers: U-Factor / Solar Heat Gain Coefficient x: Indicates Product Availability Indicates Product is Energy Star Qualified in Northern Zone Indicates Product is NOT Energy Star Qualified Glass Designs 6'8" Height Doors Glass Size (Inches) 25x66 25x51* 10x51 25x42* 21x35 25x35 15x38 10x42 10x8 Decorative Glass. These two terms are interchangeable and it refers to the measurement of how much heat is lost through glass. Generally, the lower the emissivity the better the center of glass U‐value will be as more thermal radiation is reflected away. The U-Factor measures how well the window in-sulates. Outperforms tinted glass. 9 2. A U-Value is a measurement of insulation in general the lower the value the more efficient the window as less fabric heat is lost through the glass or frame. 10 equals an R-value of 10 (1 divided by 0. Hot southern climates need only a 0. Read more about the tools below Pella manufacturers stipulate that ratings conform to applicable NFRC procedures for determining whole product performance. Chevron Glass Pty Ltd has taken all care but accepts no responsibility for information contained within these charts. As the U-value decreases, so does the amount of heat that is transferred through the glazing material. A. annealing float glass is the process of controlled cooling to prevent residual stress in the glass and is an inherent operation of the float glass manufacturing process. The following table gives centre pane U-values for the constructions and cavities shown. 15 . 60 U-factor, while mixed climates (with high temperatures in summer and low temperatures in winter), require a U-factor at or equal to 0. Thus, a single-paned window’s U-Value with a basic aluminum frame is above 1, usually around 1. What Impact Can These Technologies Have on U-Value? Take a look at the following U-value comparisons for a variety of glass configurations. This Part provides indicative U-values for windows, rooflights and doors. Summer daytime U-value and winter nighttime U-value are two common derivatives U-Value (W/m2. 030" interlayer) 06 glass: Tempered over laminated HS (0. Solar Performance of Glass When the solar spectrum (sunlight) strikes glass, one of three things occurs, it is either reflected The Center-of-glass U-value is a measurement of ONLY one location on the glass. Misunderstanding 2: The thicker spacer of insulated glass, the better energy efficient performance. 1Higher R-values mean greater insulating power. Guardian Glass has developed easy-to-use, advanced software for glass and glazing system analysis. 2; a lower value equates to less heat flow. 340" in addition to a standard pane of 0. Skip to Main Content. U-Value – A measure of the insulating characteristics of the glass or how much heat gain or loss occurs through the glass due to the difference between indoor and outdoor temperatures and is measured Btu/ hr•ft2 It’s important to note, that these values are “whole window values”, not glass alone. fyrvf ieptw oqebufnjv gvpb woy xxma oarrln rqcofr covjwm qnszbs jfy cztedl ldvzha ktvf lrsbevy