Chicago Window Expert Nobody knows more about windows.
  • By Mark Meshulam

    Mark Meshulam is an expert witness and consultant for windows, insulated glass, low-e glass, architectural glass and building facade.

    As the saying goes, one picture is worth a thousand words. Here we have six pictures, so I just saved myself 6000 words of writing. Deducting the 554 words that I have written anyway, I am still coming out ahead by 5446 words! Yet another example of energy efficiency.

    Jason Theios, P.E. Applications Engineer at Guardian provided these thermal infrared images of 5 types of insulated glass. These images are a result of actual testing – not calculation. The exterior temperature is held at 0 degrees F with a simulated 12 mph wind. The interior temperature is held at 72 degrees F.

    Color-coding for thermal gradient

    Color-coding for thermal gradient


    Images are provided courtesy of the Infrared Lab at Lawrence Berkeley Laboratory.


    Glass type 1
    Glass type 1

    Glass type 1


    1″ insulated
    2 lites clear non coated
    krypton fill
    aluminum spacer
     
    Top edge of glass: 35°F
    Bottom edge of glass: 21°F
     
    Comment: this is the only glass type using an aluminum spacer. The foam spacer is 14-17°F warmer at the bottom, which is generally the coldest part of any insulated glass unit.
     
     
     


    Glass type 2
    Glass type 2

    Glass type 2


    1″ insulated
    2 lites clear non coated
    krypton fill
    foam spacer
     
    Top edge of glass: 48°F
    Bottom edge of glass: 35°F
     
    Comment: Krypton is a gas with better insulating properties than dry air, which is more commonly used in glass airspaces. Argon gas is also used for the purpose of improving insulated glass.
     
     
     


    Glass type 3
    Glass type 3

    Glass type 3


    1″ insulated
    2 lites clear with (1) Low-E coating
    krypton fill
    foam spacer
     
    Top edge of glass: 48°F
    Bottom edge of glass: 36°F
     
    Comment: Using two Low-E coatings instead of one allows for better reflecting of outside infrared while retaining roomside heat. Due to the propensity for heat energy to bounce between the coatings and build up heat in the glass, heat strengthened glass will almost certainly be required.
     
     


    Glass type 4
    Glass type 4

    Glass type 4


    insulated – unknown thickness
    4 lites clear with ( assumed 3) Low-E coatings
    krypton fill
    foam spacer
     
    Top edge of glass: 41°F
    Bottom edge of glass: 38°F
     
    Comment: This can be costly from both a material and labor standpoint. 1/4″ thick glass weighs 3.2 pounds per square foot. In large sizes, 1/4″ glass will be needed. Four sheets of this glass will weigh almost 13 lbs/sf. A 4′ x 8′ unit, such as what we use in window-walls, would weigh over 400 pounds. That requires a lot of manpower and equipment to install, dramatically increasing cost.
     
     


    Glass type 5
    Glass type 5

    Glass type 5


    insulated – unknown thickness
     
    2 lites clear uncoated
     
    vacuum fill
     
    ceramic pillar spacers (dots)
     
    unknown edge spacer
     
    Comment:
    This is the glass development I am most excited about. Reason: I believe it will potentially have the best combination of performance and cost when the technology is perfected. Glass type 4 looks great for performance, but excessive material and labor costs of a unit consisting of 4 lites of glass seems like it might be excessive, especially in large sizes. See the “Vacuum Glazing” sections of The Future of Windows, and An Interview with Guardian for more about vacuum glass.
     



    Want to talk about energy efficient glass?

    Mark Meshulam, Chicago Window Expert, looking at glass

    Mark Meshulam, Chicago Window Expert, thinking about glass thermal transmission


    No matter where you are,
    contact me, Mark Meshulam,
    the Chicago Window Expert
    For the expert attention you deserve
    Mark@ChicagoWindowExpert.com
    Download Brochure
    Download Mark Meshulam’s CV
    Download Field Testing Credentials

    Current client locations:
    Alabama, Alberta, Arizona, Arkansas, British Columbia, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Japan, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Jersey, New York, North Carolina, Nova Scotia, Ohio, Oklahoma, Ontario, Oregon, Pennsylvania, Russia, Singapore, Tennessee, Texas, Utah, Virginia, Washington State, Washington DC and Wisconsin.
    Coming soon to your area!

    2 Comments

2 Responses to “Thermal Images of Insulated Glass Types”

  1. Hello Mark

    I have question about my home windows. Almost 11 years old double pane. When it is really cold say below freezing what I noticed. inside temperature of glass is around 48F. I am using Infrared thermometer to measure temperature. I think some is not right. It is almost everywhere in house. Near some windows I feel cold but I found it is due to loose bottom seal. I am looking for replacement windows. What is your advice?

    Thanks,
    Milind

  2. Hi Milind,

    If you are using double pane glass, you will achieve an R value of about 2. If you replace the windows with glass with a low-e coating and argon gas fill, you will increase the R value to almost 4. This would increase the interior temperature by an estimated 4-10 degrees.

    However, as you mentioned, air infiltration could be an even bigger factor. For our clients, we use testing equipment to measure the air infiltration, then we modify the windows for better air infiltration and test again. This enables us to predict long term energy savings and can also have a dramatic effect on localized cold spots in the building.

Leave a Reply

*

Generic selectors
Exact matches only
Search in title
Search in content
Search in posts
Search in pages
Filter by Categories
About windows & glass
Accident investigation
Aluminum windows
architecture
Bad replacement windows
Bad window installation
Bad window replacement
Best windows
Broken glass evidence
building design
Building Energy Benchmarking
Building envelope
Building science
caulking contractor
Construction defects
Curtainwall retrofit
Drafty windows
Energy Efficient Windows
Expert witness
Exterior facade consultant
falls from windows
Fiberglass windows
Glass
Glass breakage
Glass evidence
Glass Safety
Glass types
Introduction
leaks in walls
masonry
Mockup testing
mold in walls
My windows leak
Nickel sulfide inclusion
personal injury
Preconstruction mockup testing
PVC windows
Renewable Energy
Repair or replace windows?
Replace weatherstripping
Restoring windows
Safety glass
Safety glazing
Secondary glazing
Shower doors
Shower enclosure
solar energy
Solar Power
Spontaneous glass breakage
Steel windows
Testing windows and glass
The Construction Process
Types of glass
Vinyl windows
Web statistics
Window air infiltration
Window air leaks
Window condensation
Window dangers
window falls
Window gaskets
window replacement
Window retrofit
Window safety
Window test
Window testing
Window types
Window water leaks
Window weatherstrips
Windows and Energy
Windows leak
Wood windows
Wynn Hotel
NEW: Caulking, Tuckpointing and Window Heaters
Now offering caulking, tuckpointing and waterproofing services. We also have a system to heat windows and reduce or eliminate condensation. Contact mark@chicagowindowexpert.com
for details
Contact us!

No matter where you are,
Chicago Window Expert can help you
Mark Meshulam
Email me               CV-Resume'
Brochure      Testing Credentials
Follow us on Facebook or Twitter
for updates you won't see here
View Mark Meshulam's profile on LinkedIn

Locations

Alabama, Alberta, Arizona, Arkansas, British Columbia, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Japan, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Jersey, New York, North Carolina, Nova Scotia, Ohio, Oklahoma, Ontario, Oregon, Pennsylvania, Russia, Singapore, Tennessee, Texas, Utah, Virginia, Washington State, Washington DC and Wisconsin

Coming soon to you

Photo of the day

g3-check-pressure-gauge.jpg
The digital gauges on the lab equipment measure chamber pressure in psf (pounds per square foot) and air flow in cfm (cubic feet per minute).