Evaluating Window Insulation

Moveable Insulation Study

CCHRC evaluated eight types of common window insulation methods, including interior and exterior types of moveable insulation. Windows are an expensive part of the building envelope to replace, so people in cold climates often resort to cheaper methods, such as shutters or curtains, to reduce heat loss. Others may already have high performance windows, but want to reduce heat loss further on cold winter nights.

To help guide these decisions, CCHRC conducted a study of common window insulation methods and compared them in terms of effectiveness, affordability, ease of installation, durability, and functionality. Researchers studied a variety of methods and windows in volunteers’ homes to understand how the methods work in real-life situations. CCHRC also modeled the retrofit window treatments to help explain more generally how they can help homeowners.

This report also offers simple background information that will help explain terminology, like U-value, which measures the ability of the entire window (including glass and framing) in resisting the movement of heat.

The chart below compares various window insulation methods on the six factors we looked at.











Interior Shutter Evaluation

CCHRC worked with Fairbanks builder Thorsten Chlupp to evaluate an interior window shutter system that was designed to reduce heat loss through window while preventing moisture to condensate between the window and the shutter.

The scope of work involved the instrumentation of the new interior window shutter design and monitoring performance over one to two weeks.  Thermocouples, a heat flux sensor, and relative humidity sensors will be used to instrument the window.

This data enable us to:

  1. evaluate the center of glass resistance to heat loss with and without the new interior window shutters address the following questions;
  2. evaluate the condensation potential of the window; and
  3. compare this shutter performance (in terms of both ease of use and cost to homeowner) with previously tested systems.


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Evaluating Window Insulation ReportReports


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