Insulated Glass
Insulated glass is one of the most common and effective methods to increase the thermal performance of a window. Combine with low-E and reflective coatings to achieve even greater thermal and solar performance values.
ITI Glass has manufactured quality insulated glass units since 1975 and sources some of the largest units in the Midwest. Automated equipment produces units up to 106 inches x 196 inches. Production line and integrated washer, installed in October 2009, have significantly improved production handling for soft coat low-E and other specialized glass types.
By sealing a dry air space between two or more lites of glass, insulated glass increases the overall thermal performance of a window. In an insulated unit, the dry sealed air space reduces the difference between the building's interior climate and the outdoors. This buffer decreases energy transfer and reduces the formation of condensation in cold climates.
Insulated Glass Production
At ITI Glass, insulated glass units are manufactured on a vertical Bystronic® production line. Units have two or more lites of glass separated by a machine-bent, desiccant-filled spacer to absorb the unit's internal moisture. Spacer ends are joined together by a single metal splice. ITI Glass uses clear finish, black and bronze painted spacers, and offers a warm-edge spacer for improved insulating performance.
Insulated units are sealed twice. The unit's primary seal, bonded with an organic polysulfide, anchors the spacer to each lite of glass. A standard secondary polyisobutylene (PIB) seal fills the area around the spacer along the unit's perimeter. Silicone sealing is available for long-lasting durability in structural glazing applications.
Quality & Production Standards
Insulated glass units form ITI Glass are certified by Associated Laboratories Inc. (ALI), one of the largest third-party testing companies in the United States. Additionally, as a member of PPG Industries’ Certified Fabricator Program, ITI Glass submits to annual audits by PPG to ensure quality production of all products, including insulated units.
ALI and PPG conduct annual in-plant audits, during which auditors spend a significant amount of time observing insulated unit production. Auditors address all aspects of insulated unit production, including seal quality and unit construction. ITI Glass also submits unit samples to ALI for compliance testing according to ASTM E2190-08 Standard Specification. ITI Glass' internal standards for shipping insulated units meet or exceed all requirements of ASTM C1036-06, ASTM C1048-04 and ASTM C1376.03.
ITI Glass has maintained continuous certification with ALI for more than 20 years and has passed PPG’s CFP certification since its acceptance into the program in 2006.
Improving Efficiency with Low-E & Argon
Specifying low-E glass improves the thermal and solar performance of an insulated glass unit. The table below compares three 1-inch thick clear insulated units: One with uncoated clear glass; one with PPG Sungate® 500, a hard coat or pyrolytic low-E; and one with PPG Solarban® 60, a soft coat or MSVD low-E:
| Glass Type | Winter U-Value | Summer U-Value | Shading Coefficient | LSG |
|---|---|---|---|---|
| Uncoated Clear | 0.47 | 0.50 | 0.80 | 1.13 |
| PPG Sungate® 500 (2) | 0.35 | 0.35 | 0.70 | 1.20 |
| PPG Solarban® 60 (2) | 0.29 | 0.28 | 0.43 | 1.86 |
Lower U-Values indicate more efficient thermal insulating performance. In the table, Sungate 500 shows a significant improvement compared to uncoated glass, and Solarban 60 advances insulated performance a step further. Argon also increases the thermal efficiency of an insulated glass unit and is often specified with low-E to achieve a better overall U-Value.
Light to Solar Gain (LSG) ratio compares the total amount of daylight transmittance relative to solar heat gain, where 1.00 represents an equal balance of visible light transmittance and solar heat gain. A higher LSG ratio indicates greater amounts of visible light transmittance with a lower, more efficient, Solar Heat Gain Coefficient. In the table above, Solarban 60 strikes a much higher ratio of visible light transmittance and low solar gain compared to uncoated glass.
ITI Glass stocks several hard and soft coat low-Es that can improve the thermal efficiency on an insulated unit as detailed above.
