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Inner window facts

InnerWindows Insulate your Home
InnerWindows=50% Lower U Factor

InnerWindows lower the U Factor, or thermal heat gain, of your windows. The lower the U Factor number, the greater the insulating value of the window system. U Factor is relevant in both the cold and hot weather. If you touch your existing glass windows on a cold day, the glass will feel cold. You are paying to continuously to heat that glass surface while it is being bombarded with cold air from the other side. An InnerWindow installed with that existing glass window will feel much warmer. Quite simply, the InnerWindow has created an insulating air pocket between itself and the glass window. The air pocket keeps the interior surface warm, blocking the cold air and dramatically eliminating the transfer of heat to the outside. On hot summer days, InnerWindows keep your interior windows cool in much the same way.In addition, InnerWindows protect your windows from condensation. In some homes, the warm, moist interior air creates damaging condensation when it contacts the cold window glass, destroying window frames and walls. Adding an InnerWindow to ANY single pane glass window dramatically lowers the U factor and saves an average of $12.40 to $18.63 per year in energy costs in the Virginia area.  In fact, adding an InnerWindow to your existing window yields a better U factor rating that replacing the window with standard grade double pane windows.

InnerWindows Eliminate Drafts
InnerWindows=16% Reduction in Infiltration

InnerWindows dramatically minimize infiltration of air from around the existing window. This draftiness is actually a larger source of lost energy and home discomfort than U Factor. [insert drawing of home with air coming in around windows and drawing of same window with air turning back] We have tested the effectiveness of Capitol InnerWindows by hiring an independent energy auditor to conduct Blower Door Tests on a home in which we have installed InnerWindows. The Blower Door Test uses sophisticated technology to pressurize the home and calculate air infiltration. With InnerWindows in place, air infiltration in the home was reduced over 16%! That translates into a much more comfortable home.

InnerWindows Block Exterior Noise
InnerWindows=60-80% Sound Reduction

InnerWindows create a sound barrier between your home and the outside world. The air space created between the original window and the InnerWindow keeps 60% of disturbing exterior noises outside. In situations where excessive noise is present such as a nearby busy street or flight path, InnerWindows offers an Acoustic upgrade for some or all of your windows. Building on our original model, the Acoustic Upgrade adds additional sound abatement across all frequency levels. Acoustic InnerWindows achieve up to an 80% sound reduction with an STC rating as high as 49. This is accomplished through our utilization of heavier weight acrylic combined with high performance, closed cell acoustical foam.

Sound Reduction Chart

Click for Acoustical Test Data

InnerWindows Block UV Light
InnerWindows=85-98% UV Light Reduction

InnerWindows block 85% of the sun's harmful UV light, protecting your textiles and artwork. We also offer additional UV protection with our SunGuard Upgrade. With SunGuard, your InnerWindows will block 98% of the UV light. SunGuard is particularly appropriate in museum settings.

Fastest Payback Guaranty

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Blower test results