coated glass presentation - ar04.2019 v2silent · glass itself, they are extremely durable and...

NATIONAL GLASS ASSOCIATION | THE VALUE-ADDED PERFORMANCE OF COATED GLASS

Program Registration

BNP Media is a registered provider with the American Institute of Architects Continuing Education Systems. Credit earned upon completion of this program will be reported to CES records for AIA members. Certificates of Completion for non-AIA members are available upon request.

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods and services will be addressed at the conclusion of this presentation.


Learning Objectives

1. List two reasons glass is coated.2. Compare and contrast reflective and low-e coatings.3. Understand the difference between VLT and UV4. Describe the three cost-saving opportunities provided by coated

glass.


Why Is Glass Coated?

• To meet needs specific to the visible portion of the spectrum (380 to 780 nanometers)o Used as optical filters

• To improve the solar and thermal performance of float glass without changing the composition of the glass itselfo Used as solar filters and thermal barriers

• To change the surface characteristics of the glasso Used as glass surface modifiers


How are coatings used as filters?

Coatings alter light transmission, reflection and absorption characteristics at different portions of the solar spectrum.

% transmission + % reflection + % absorption = 100% • Change the visible appearance of float glass by:

o Vary light transmission without changing glass compositiono Vary light reflection as desiredo Changing the transmitted or reflected color as desired

• Change the solar and thermal performance characteristics of the glass by:o Reducing the ultraviolet transmission of the glasso Reducing the near-infrared transmission of the glasso Increasing the far-infrared energy reflection capability of the glass

• Modify aesthetics and thermal performance at the same time


What are other uses for coatings on glass?

To change the surface property of the glass by:• Improving abrasion resistance of the glass

o Glass can be marred or scratched by many materials in the manufacturing and fabrication process

• Reducing the reflectivity of the glass surface• Improving resistance to chemical attack of the glass surface

o Glass can “corrode” or degrade under severe storage conditions Coatings can be applied to the glass to reduce surface corrosion

• Altering the surface characteristics of the glass when in contact with moistureo Glass surfaces can be modified to impart hydrophobic or

hydrophilic behavior• Low maintenance / photocatalytic surfaces


• The number of glass surfaces depends on the glass type:o Monolithic glass

• A single piece of glass has two surfaces– Typically both surfaces available for coating

o Laminated glass• Two pieces of glass bonded together by an interlayer in a

lamination process– Typically four surfaces available for coating

To which surfaces of the glass are coatings applied?


• The number of glass surfaces depends on the glass type:o Insulating glass unit (IGU)

• Two or more pieces of glass with a total of four or more surfaces

– Typically four surfaces available for coating for dual pane IGU– More surfaces are available when one or more pieces of the

insulating glass unit are made from laminated glass

• Coatings can be applied to any of these surfaces

To which surfaces of the glass are coatings applied?


Glass Surface Identification

¼ in. (6 mm) thick glass

11 22Surfaces


11 22 33 44

¼ in. (6 mm) thick glassOuter Lite¼Outer Lite

¼ in. (6 mm) thick glassInner Lite¼Inner Lite

0.060 in. (1.52 mm) Interlayer0.060 in. (1.52 mm) Interlayer

Surfaces



11 22 33 44

¼Outboard Lite with Low-emissivity Coating #2 Surface

¼ in. (6 mm) thick glassOutboard Lite with Low-emissivity Coating #2 Surface

¼ in. (6 mm) thick glassInboard Lite¼Inboard Lite

½ in. (12 mm) Spacer & Sealant System

Surfaces



Pyrolytic Coated GlassCoatings containing a conductive oxide infrared reflecting layer, usually tin-oxide based, typically deposited during the float glass manufacturing process. Often called “hard coat”.

Sputter-Coated GlassCoatings containing multiple layers of metals, each with a different purpose such as thermal and solar performance, light transmission, reflectance, durability, etc. For Low-E coatings there is typically an infrared reflecting layer, usually silver. These coatings are typically deposited by the sputtering process in a vacuum deposition machine separate from the glass manufacturing line. Often called “soft coat”.

Types of Coatings


There are currently two ways to manufacture low-e products: • Pyrolytic process • Vacuum coating process

PYROLITIC PROCESS [Also called "hard-coat" or "on-line" coatings] can be broken down into either a vapor or liquid deposition process, which simply refers to the coating delivery system.

Pyrolytic products are created by spraying the coating onto the glass in a process called on-line deposition. The coating is sprayed onto the glass in the hot-end of the float glass manufacturing process, where the glass is still semi-flexible and has not cooled to a rigid, room temperature state as yet. In general High temperature application is the reason Pyrolytic coatings are very durable because the coating is fused to itself and to the glass.

Manufacturing Processes


Hot Application Process• Applied on the Float Line at High Temperatures• Liquid or Vapor Deposition• Coating Fuses to Itself and to the Glass

Pyrolytic Coating Process


• Chemical Vapor Deposition (CVD) Process

• Performed in-line on the float glass line

• Chemical coating is bonded to the glass while it is in a semi-molten stateo Polycrystalline layer of an oxide

• Chemical compound becomes a part of the glass surface

• Also called “Hard-Coat”

Pyrolytic Coating Process


• Pyrolytic coatings are typically metallic oxides applied during manufacturing, as the glass ribbon flows over the liquid tin—and before it is lifted out onto rollers.

• Because these coatings are a permanent part of the glass itself, they are extremely durable and tough—hence the common name “hard” coating.

• Glass products that feature a pyrolytic coating have a number of advantages:o Easy to handle, transport, stack, and store.

o Can be heat-treated and laminated to meet specialized applications.

Pyrolytic Coatings: Hardness Benefits


• There is no need for edge deletion when incorporating pyrolytic glass in an insulating unit.o “Edge deletion” means removing a portion of the coating

at the perimeter of the glass, to ensure no coating is exposed to the atmosphere.

• Pyrolytic products are strong enough to be used monolithically, though this is product specific.

• Pyrolytic coatings can be exposed to weather—positioned on the #1 surface—again this is product specific.

Pyrolytic Coatings: Environmental Benefits


• Pyrolytic Film Propertieso Durable (mechanically and chemically)o Long shelf-lifeo Temperable with little change in appearanceo Less susceptible to scratchingo Bendableo Fabrication friendlyo Moderate Low-E performance for some materials

• Can be placed on the #1 or #4 surface.• Can be used monolithically (exposed coatings).• Usually used with heat absorbing (tinted) glass to

reduce solar heat gain and improve solar performance.

Pyrolytic Coatings Summary


• Residential and commercial glazing applications.

• Areas of the world where sputtered coatings may be too delicate.

• Suitable for climates where passive solar heat gain is a benefit.

Pyrolytic Coating Uses


• Sputtering:o The deposition of atoms in a vacuum onto a glass

substrate using a momentum exchange process.o Known as vacuum deposition.

• Sputtering Processo An energetic ionized gas is trapped in a magnetic field

and used to bombard a target material. Atoms of the target material are dislodged and then impact and adhere to the surface of glass which is passing below.

o A magnetic field – also known as a “magnetron” – is used to enhance the deposition rate.

Sputtering Process Overview


• Non-Reactive Sputteringo Argon is the gas (inert)o Atoms of target material condense on substrateo Yields pure metals

• Reactive Sputteringo Reactive gas is usedo Atoms of target material react with gas and make a new

molecule.o Atoms of new material condense on the substrate.o Yields oxides and nitrides.

Two process variants used to sputter:

Sputtering Process Overview


Sputtering Process

• The picture on the following slide depicts what is going on inside the high vacuum chamber of magnetron sputtering equipment.

• You can see the gas flows in through gas bars along the length of the target.

• The magnets mounted behind the target create a plasma zone which energizes the gas molecules in order to impart momentum high enough to knock the target atoms loose.

• On the bottom you can see the glass passing under the target, where the target atoms or molecules are building up.


Sputtering Process


• A range of target materials can be used to provide many different coating options to enhance performance and aesthetics.

• Sputter coatings have a high solar and thermal performance – saving energy for commercial and residential structures in all kinds of climates.

• Many sputter coatings are spectrally selective as defined by the U.S. Department of Energy (i.e., light-to-solar-gain ratio of 1.25 or greater) – reducing need for artificial light.

• Some sputter coatings can be cut, tempered and fabricated after coating has been applied – allowing local inventory to be maintained and provide for shorter lead times on fast-track projects.

• Some sputter coatings can provide extra-hard scratch-resistant surface to shed moisture and resist scratching.

Sputtering Process: Benefits


• For high energy efficiency in:o Commercial structures, including hospitals, schools,

arenas, high rise apartments.o Residential buildings – a variety of products to suit

almost any climate.• For pleasing aesthetics and sharp optics in both

commercial and residential buildings.• To resist scratching – table tops, jewelry counters,

subway windows.

Sputtering Process: Uses


• To resist moisture and grime – shower stalls.• Many sputter coatings can be heat-treated, laminated,

and otherwise fabricated to meet project requirements

• Can be bendable• Widely available

Sputtering Process: Uses


• Mirrors are the second most important coatings in the glass industry after Low-E coatings.

• Most mirrors in North America have traditionally been silver mirrors. In Europe, aluminum mirrors were the norm up until the 1980’s.

• More than 900 million square feet of silvered mirrors are produced annually.

Coatings for Mirror Applications


• Silver mirror applications (back-side mirrors):o Furniture decorationso Bathroom and sanitary applicationso Ornamental applicationso Automotive mirrorso Pocket mirrors and fashion

accessorieso Display cabinets and shop windowso Technical applications such as solar

power stations.



• Aluminum mirror applications (often first surface mirrors):o Photocopierso Cameraso Overhead projectorso Lasers

• Chrome mirrors:o Side and rear-view automotive

mirrors.



Chemical Reduction Application Method

• Most common method used today to make silver back-side (#2 surface) mirrors is the chemical reduction spray method.

• Chemical reduction is also known as ‘electroless plating’ where metals are reduced from a compound with the help of a co-reactant to form a layer on the glass surface.o Many metals can be deposited using this method

but silver is the most common.



First Surface Mirrors (FSM)

• Made using the sputtering processo Aluminum with reflection-enhancing layers that also

serve as corrosion protection layers.o 90%+ visible light reflectanceo No internal glass losses due to the reflection coming off

the first surfaceo Used in projection televisions as the projection mirroro Surface quality is of utmost importance



First Surface Mirrors (FSM)

• Made using the pyrolytic (CVD) processo Referred to as a two-way mirroro Durable coated surfaceo 68% visible light reflectance from

coated surfaceo 16% visible reflectance from un-

coated side• Coated surface should be installed facing

the subject sideo Subject side should have higher

illumination levelo Recommended lighting ratio of 8:1

for optimized masking and observation ratios



Transparent Mirrors

• Created for unobtrusive observation in interior applications.

• Ideal for surveillance and security applications where discreet observation is required.



• Transparent Mirror Applications:o Focus Groupso Police Lineupso Television Cabinetso Day Care Centerso Retail Securityo Airport Securityo Factory Officeso Hospitalso Education



• Question: How do we modify the behavior of glass to make windows conserve energy and look different/same?

• Answer: Change the interaction between the glass and light using coatings to modify transmission, reflection and absorption across the solar energy spectrum.

Solar & Thermal Performance Applications


Today, architects can choose from a wide range ofcoated glass products that meet different criteria forfunctionality and performance:

• Reflective/Solar Control• Low-Emissivity (Low-E)• Combinations of Reflective/Solar Control and Low-E

Overview of Coated Glass Types


To further improve the performance of glass, manufacturers have developed various types of coatings that can be applied during the float process, or as part of an off-line process.

• Coatings can be applied either during the float process or off line from the float process.

• Both reflective and Low-E coatings offer excellent solar control, minimizing heat gain.

• Low-E coatings offer improved U-factors providing better overall insulating properties.

Value-Added Performance


• Windows and doors are the most significant source of heat transfer in a home, regardless of climate or season.

• Window & door manufacturers have innovated with improved designs and more energy efficient components.

• Glass manufacturers have developed low-e coated glass.

Windows & Doors41%

Wall22%Basement

6%

Floor20%

Roof11%


Heating and cooling represent approximately 45% of a typical Home Energy Budget



Low-E Glass Keeps The Heat Where You Want It, Regardless Of The Climate Or Season

Rejects Excessive Solar Heat, Keeping You Cool When It’s

Hot Outside

SHGC

Retains Furnace Heat, Keeping You Warm When

It’s Cold Outside

U-Factor



Low-E Glass Transmits Natural Daylight And Reduces Damaging UV Radiation

Visible Light

Transmits Natural Daylight, Brightening Your Home

And Your Mood

UV

Reduces Damaging UV Rays, Protecting Home Furnishings


A certain amount of solar energy is transmitted through the fenestration product to the interior of the building. The coating design engineer has the ability to impart changes to the glass properties such as:

• Visible Light Transmissiono The amount of day light that is passed through a window.

This is usually expressed as a percent.

• Ultraviolet (UV) Transmissiono The amount of the UV portion of the solar spectrum that is

passed through a window. This is usually expressed as a percent.

Solar & Thermal Performance Terminology


The coating design engineer also has the ability to impart changes to:

• Near Infra-Red (Near-IR) Transmissiono The amount of the Near-IR portion of the solar

spectrum that is passed through a window. This is usually expressed as a percent.

• Solar Energy Transmissiono The total amount of solar energy that is passed

through a window.o The sum of visible, UV and Near-IR energy

transmission.



• Solar energy is the energy transmitted in the range of 300 to 2500 nanometers.

• Solar transmittance is defined as the percentage of ultraviolet, visible and near infrared energy within the solar spectrum that is transmitted through the glass.


• This describes how much UV, visible and Near-IR energy is allowed inside a building through its glass.

• Solar energy can be transmitted, reflected, or absorbed by the glass.


Emittance• Expressed as a number between zero and one.• The measure of a surface’s ability to emit long-wave

infrared radiation: the ratio of the radiant energy emitted by a surface to that emitted by a black body at the same temperature.

• A lower emittance value indicates reduced radiative heat flow.

• A so-called perfect black body can emit heat at a value of 1.

• A perfect non-radiant product would have a rating of 0.• Low-e glass is designed to have as low a value as possible.

High performance low-E glass products have been designed to have an emissivity of less than 0.04.



U-Factor (or U-Value)• A measure of the heat gain or loss through glass due to the

difference between indoor and outdoor temperatures. • The lower the number the better the material or assembly is

at blocking heat transfer.• For instance, standard float glass has a U-factor close to 1 Btu

per hour - foot squared - degree Fahrenheito A high performance low-e product used in a well-

designed dual pane IG construction can improve U-factor significantly, up to 4 times better



R-Value (the inverse of U-Value)• A measure of the resistance of a window to non-solar heat

transfer.• A higher R-Value indicates greater resistance to heat flow and

better insulating performance.

Solar Heat Gain Coefficient (SHGC)• The amount of the solar heat that is passed through a window,

as well as the amount that is absorbed by the glass and reradiated to the interior. This is expressed as a number between zero and one.

• A lower SHGC indicates that less solar heat is transmitted through the window.



Shading Coefficient (SC)• The ratio of the solar heat gain through a specific glass

product to the solar heat gain through a lite of 1/8 in. (3mm) clear glass.

Light-to-Solar Gain Ratio (LSG)• The visible light transmission (VLT) of a glazing system

divided by the solar heat gain coefficient (SHGC).

Relative Heat Gain (RHG)• The amount of heat gain through a glass product

combining the effects of solar heat gain (shading coefficient) and conductive heat gain (U-value).



The Evolution of Window Glass has Improved Comfort, Energy Efficiency, and the Life-Span of Typical Home FurnishingsWith (Low-E) Coated Glass:• Heat loss is reduced• Heat gain is reduced• Glass temperatures and occupant comfort level have been

improved• Daylight has been maintained• Fading and deterioration have been reduced

SHGC

(Daylight) (Fading) (Solar Management)

air argonMonolithic, Clear 3mm Glass 90% 72% 0.87 90˚ F 15˚ F 1.11 n/a

IGU, Clear 3mm Glass 82% 57% 0.77 90˚ F 44˚ F 0.48 0.46

IGU, Low-E, Clear 3mm Glass 70% 29% 0.36 83˚ F 56˚ F 0.29 0.24

(Thermal Management)

U-Factor

(Summer / Winter)

Glass PackageVisible Light UV Light

Room-Side Glass Temperature

Solar & Thermal Performance


The next slide shows the electromagnetic spectrum.

Most of us think of visible light as a color rainbow. However, we are all aware of UV light (tanning bed) or short wave IR (your home oven). The visible spectrum is just a thin slice of the overall spectrum.

Of the electromagnetic spectrum, the solar spectrum consisting of the ultraviolet, visible and near infrared energy is from about 300 to 2500 nanometers.

The visible light spectrum as seen by humans is from 380 to 780 nanometers.

Electromagnetic Spectrum


Coatings are designed to influence key parts of the electromagnetic spectrum.



Graph shows the visible spectrum (rainbow arrow) and the transmission effects of a sputtered coating with a single, double and triple silver layer. The sputtered coating with silver layers allows MOST of the visible light to be transmitted but transmission of UV and IR is greatly reduced.

— Single Silver — Double Silver — Triple Silver


If it is not transmitted – it means it is absorbed or reflected back to the source environment.


— Single Silver

— Double Silver

— Triple Silver


This graph represents the reflective properties of sputtered low-e coatings made up of single, double and triple silver layers.

NATIONAL GLASS ASSOCIATION | THE VALUE-ADDED PERFORMANCE OF COATED GLASSwww.energystar.gov

Energy Star ® Windows Regional Performance Guide

The US and Canadian Energy Star program is utilized by the commercial and

residential markets as a value proposition or product differentiator. Different

fenestration products are designed for a given region and performance

requirements, or may be designed to be universally used in any region. Low-e

coatings provide a means to obtain the energy requirements of a given region.


North Central Region – mixed heating and cooling climate• U-factor 0.30 or lower

o The larger your heating bill, the more important a low U-factor becomes.

• SHGC of 0.40 or lower• The lower the SHGC, the less energy is used for cooling.



South Central Region – mixed heating and cooling climate• U-factor 0.30 or lower

o A low U-factor is useful during cold days when heating is needed. Also helpful during hot days when it is important to keep the heat out, but it is less important than SHGC in warm climates.

• SHGC of 0.25 or lowero A low SHGC is the most important window property in

warm climates



Southern Region – cooling dominated climate• U-factor 0.40 or lower

o A low U-factor is useful during cold days when heating is needed. A low U-factor is also helpful during hot days when it is important to keep the heat out, but it is less important than SHGC in warm climates.

• SHGC of 0.25 or lowero A low SHGC is the most important window property in

warm climates



• The use of Low-E coatings is required in all zones.

• Commercial construction is following a similar trend to residential.

• As energy costs increase, there is a need to better market Low-E coatings to the end consumer.

Low-e Coatings Summary


High Performance Glass

Simulated Building Model & Energy Savings


Heat – Natural GasA / C – Electric

Locations: Floor Area: Number of Stories: Floor-to-Floor Height:

Window Type:

Window Area:

Ceiling Insulation:

Wall Insulation: Energy Source:

Chicago & Miami120,000 sq.ft.612 ft.

Strip Windows

20,000 SQ.FT.

R-19 in ChicagoR-15 in Miami

R-13

Office Building Assumptions


6mm monolithic clear float glass is to be compared with• 6mm clear• 6mm clear IG • 6mm coated• 6mm clear IG combinations

Glazing Options


Glazing Options: Performance Comparison

The chart on the next slide shows a performance comparison for various glazing options.

Different applications and different regions of the country use different combinations of glass in the IGU to maximize the benefits desired.

For instance, the chart shows that a double silver sputter coated glass in an IGU provides the best U-factor with a fairly high visible light transmission.

The numbers referenced on the vertical axis will be used again in subsequent slides.


Mono 89% .82 1.1

IGU 80% .71 .48

IGU 68% .37 .29

IGU 50% .39 .34

IGU 43% .26 .31

IGU 40% .31 .33

IGU 18% .20 .41

Monolithic / IGU

% VisibleLight

TransmissionShading

Coefficient U - FactorGLAZING

3. High Light TransmissionDouble Silver Low-E

2. Clear IGU

(6mm clear, coating #2 surface/12mm AS/6mm clear)

4. Medium Light TransmissionSingle Silver Low-E

5. High Reflectance, Med. Trans.Single Silver Low-E

6. Med-Low Light TransmissionSingle Silver Low-E

1. Clear Float Glass

7. Low Light TransmissionReflective/Solar Control

Glazing Options: Performance Comparison


The cost saving components that can be applied to the example building include:

1. One-Time Savings from Reduction in HVAC System Cooling Capacity

2. Annual Savings from Reduced Energy Consumption for Cooling Requirements

3. Annual Savings from Reduced Energy Consumption for Heating Requirements

Cost Savings Components


#7

$16,000

$26,000

$24,000

$20,000

$22,000

$24,000

$24,000

#4 #6

One-Time HVAC Savings (compared to a clear I.G. unit)

Chicago Miami

$6,000

$28,000

$30,000

#5#3 #7#4 #6 #5#3

Analysis Results provided by Guardian Glass, LLC

Cost Savings Results

This shows the one-time cost savings for a specified HVAC system for various types of glass for a building in Chicago versus the same building in Miami.

For Chicago, the biggest savings in HVAC cost is associated with choosing a low solar gain, reflective type sputtered coating which is calculated at $28,000. For comparison, the one time savings over choosing a typical double silver low-E sputtered coating is 40%.By contrast, for the building in Miami, any coating provides a decent savings in a cooling dominated region, but again the highly reflective low solar gain coating provides the biggest savings.


$6,325

$5,009

$16,683

$8,601

$6,511

$13,357

$10,853

$13,127Annual Energy Savings (compared to a clear I.G. unit)

$10,131

$8,930

#7#4 #6 #5#3 #7#4 #6 #5#3

Chicago Miami



Annual energy savings for both buildings is compared. It can be seen that there is a bigger gain possible in a cooling dominated climate, as the cost for cooling is greater when compared to the cost of heating.

In Chicago the best thermal performance is obtained by specifying a single silver solar control sputtered coating, however, light transmission is reduced.

For Miami, the best performance comes from specifying a typical high performance solar control sputtered coating which significantly cuts down solar gain.


$79,250

$56,090

$196,830

$106,010

$93,110

$155,570

$132,530

$125,310

One-time HVAC capital expense savings

10-Year Energy Savings(compared to a clear I.G. unit)

$155,270$115,300

#7#4 #6 #5#3 #7#4 #6 #5#3

Chicago Miami



This chart shows the 10 year return based on both the one-time HVAC capital expense savings and energy savings. It should be clear that the annual energy savings dominates the total savings. In Chicago the best performance is obtained by specifying a single silver solar control sputtered coating for a total savings amount of over $115,000.For Miami, the best performance comes from specifying a typical high performance solar control sputtered coating which provided a total 10 year savings of over $196,000.


High Light Trans.Double Silver Low-E

(Chicago)

IncrementalUnit Cost per sq.ft. Sq. Ft.

Annualized Savings

Payback Period

Incremental Glass Cost

HVACCapital Savings

High Reflectance, Med. Trans.Single Silver Low-E

(Miami)

compared to a clear IG unit

$ 2.00 20,000 $40,000 $20,000 $8,601 2.3 Yrs

$ 2.00 20,000 $40,000 $24,000 $13,127 1.2 Yrs


Return on Investment

From the previous results, it should be clear that specifying the right coating can yield a decent return on incremental investment. Balancing performance with aesthetics is a decision that can be made in conjunction with the glass supplier.

This example shows that choosing a high performance double silver low-E sputtered coating for Chicago yields an annual savings of $8600 and provides a payback period of 2.3 years. The same building in Miami with a Single Silver Solar Control low-E sputtered coating provides a calculated annual savings of $13,100 and has a payback period of 1.2 year.


• Tremendous energy cost savings

• HVAC system cost reductions and annual energy cost savings

• Ten year savings - several hundred thousand dollars for a typical six-story building. Savings continue for the life of the building

• The Return on Investment can be less than one year if using a tinted substrate instead of clear

Analysis Results provided by Guardian Glass LLC

Summary of Energy Cost Savings


Diamond-Like Carbon (DLC)• Can be added to the surface of the glass to impart extreme

scratch and abrasion resistance.o Thickness determines transmittance, reflectance and color

aesthetics.o Usually very thin, half as thick as a human hair

• Can modify the glass surface to provide hydrophobicity.o Changes the surface tension of the glass to cause beading

(repels water)• Can modify the glass surface to provide hydrophilicity.

o Changes the surface tension of the glass to cause sheeting (attracts water)

Coatings for Glass Surface Modifications


• Coating fused onto glass surface• Seals surface• Harder than glass• Permanent• Prolongs properties of fresh

glass• Protects against

o Corrosion and discolorationo Leaching, pitting, and stainingo Mechanical damage from

cleaners with abrasives

Shower Enclosures


• Prolonged exposure to liquids or vapor, such as water, causes the sodium/alkali ions to migrate to the surface of the glass. o Cloudiness or haze during high

humidity storage or if the glass becomes wet and sits unused for long time periods.

o Attacked by concentrated sodium hydroxide and other strong bases.

o Affected by hydrofluoric and phosphoric acid (etchants).

• Coatings can be applied to the glass surface to substantially reduce surface corrosion.

Untreated Treated

Glass Surface Corrosion Protection


• UV blocking chemicals can be applied to the glass surface.

• Reduces effect of the harmful UV rays which cause irreversible fading and damage to treasured artwork, window treatments, floor coverings and furniture.

• Works to minimize the bleaching effects caused by exposure to UV light.

UV Control Coatings


Low maintenance glass is defined as a product that has three distinct characteristics.• The glass has a durable, long-lasting coating bonded

to the glass during manufacturing.• The coating exhibits photocatalytic properties.• The same coating also exhibits hydrophilic properties.

Propertiesof Low Maintenance

Glass

Low Maintenance Glass Products


Photocatalysis = The decomposition of organic material as a result of exposing the coating to UV radiation.UV light from the sun energizes the self-cleaning glass coating to help slowly break down and loosen organic dirt. Since UV light is abundant even on cloudy days or in shaded areas, this process works nonstop throughout the day.


Windowswith

TraditionalGlass

Windowswith

Self-CleaningGlass

PhotocatalyticProcess


Hydrophilic = Relating to a surface (e.g. glass) that has a strong affinity for water, causing sheeting. Opposite of Hydrophobic (beading)

The hydrophilic properties of the low maintenance glass make water droplets spread out, or sheet, across the surface. When rain or a light spray of water hits the window, the dirt is more effectively rinsed away.

The sheeting action accelerates the drying time of the glass and also helps the window to naturally dry with minimal spotting or streaking.

~40º <10º >90º



Hydrophilic Process


Windowswith

Self-CleaningGlass

HydrophilicProperty

Windowswith

Self-CleaningGlass

HydrophilicProperty

Windowswith

TraditionalGlass


Summary• The glass is photocatalytic; the coating is activated by UV rays. • The glass is hydrophilic; the coating allows water sheeting

action.• Coating is durable and long lasting.• Offers improved thermal/optical qualities vs. regular clear

glass.



Benefits• UV rays work to slowly break down and loosen organic

dirt on the glass surface. • Sheeting action allows more efficient rinsing. • Glass surface dries more quickly with minimal spotting

and streaking. • Reduction in UV transmittance. • Potential reduction in SHGC.




Conventional Glass Self Cleaning Glass

A depiction of the sheeting action of low maintenance glass on the right compared with conventional uncoated glass on the left.


This concludes The American Institute of ArchitectsContinuing Education Systems Course

The Value-Added Performanceof Coated Glass

1945 Old Gallows Rd Ste 750Vienna, VA 22182

703.442.4890

www.glass.org

Conclusion


Industry Resources

National Glass Association, with GANA www.glass.org

• Glass Informational Bulletins• Glazing Manual• Laminated Glazing Reference Manual• Protective Glazing Manual• Sealant Manual• Specifiers Guide to Architectural Glass


Glass Magazinewww.glassmagazine.com

American Architectural Manufacturers Association www.aamanet.org

ASTM Internationalwww.astm.org

Insulating Glass Manufacturers Alliancewww.igmaonline.org

USGlass Magazinewww.usglassmag.com

Industry Resources


National Fenestration Rating Council (NFRC) approved resources to perform thermal and optical simulations:

Lawrence Berkley Labs (www.windows.lbl.gov)• International Glazing Database (IGDB)• Optics• RESFEN• THERM• WINDOW

Check with your glass supplier – they have many programs available to customers which incorporate the properties of their specific coated glass products into design programs.

Software Resources

coated glass presentation - ar04.2019 v2silent · glass itself, they are extremely durable and...

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