The ancient Greeks used holes in walls to admit light into their buildings. The problem was that with the light came rain, wind, insects, cold, and heat. The thermal performance of this strategy would be rated at approximately R-1.
In more modern times, we installed a single pane of glass in the hole, which kept out the rain, wind, and insects. However, this single pane of glass did nothing to keep out the cold of winter or the heat of summer. The thermal performance of these openings also would be rated at approximately R-1.
By the 1980s, we were using insulating glass and thermally broken window frames to improve thermal performance. Windows of this type were able to achieve a thermal performance of R-2 or greater.
In the 1990s, we began using gas-filled and low-emissivity (low-E) coated glass, which improved thermal performance to approximately R-3 or greater.
Now, there is the Renovate system, which uses a hermetically-sealed, triple-pane insulating glass unit (IGU) with low-e coatings on one or two surfaces, and an argon gas-filled cavity. Through this revolutionary window retrofitting system, windows are able to achieve thermal performance ratings ranging between R-5.5 to R-6.67!
|1/4" Clear||RbB Platinum||RbB Platinum Plus II||RbB Platinum Plus II XL|
|Visible Light Transmission||89%||63%||56.7%||50%|
Renovate System Coatings
The Renovate system utilizes high-performance, double and triple glass coatings. Depending on the chosen configuration, there may be one or two low-e glass coatings with the Renovate system.
Below is a brief explanation of the three coatings that may be incorporated into the Renovate system, with information about the dramatic energy savings they can achieve.
DOUBLE-SILVER Solar Control Low-E Glass
With its ability to block 62 percent of total solar energy, while allowing 70 percent of visible light to pass through, Double-Silver low-e glass can help you achieve a building design that provides year round comfort with heating and cooling cost savings.
Cost Savings and Increased Efficiency with TRIPLE-SILVER Low-E
Realizing the benefits of specifying Triple-Silver glass can happen even before the project is completed. Thanks to the unequalled solar control characteristics of Triple-Silver glass, smaller HVAC systems may be specified for buildings glazed with this product, potentially reducing the associated upfront capital investment by as much as $124,000. As a result, by specifying Triple-Silver glass instead of other solar control low-e coated glass products, you may have your investment repaid in a matter of months. With its increased ability to repel heat gain, Triple-Silver glass is ideal for south-facing elevations and/or southern climates.
Added benefit of a PYROLYTIC passive low-e coating
With its ability to transmit the warming rays of the sun, a Pyrolytic passive low-e glass offers the perfect balance of energy efficiency and interior comfort for heating-dominated climates
In colder climates where higher insulating values are required, the Pyrolytic coating is placed on the No. 4 surface of an IGU with a solar control, low-e glass such as a Double-Silver or Triple-Silver on the No. 2 surface. This configuration yields a 20 percent net gain in U-value.