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Compared to window replacements, secondary windows are a cost-effective and efficient way to improve thermal performance and occupant comfort and reduce noise.
Researchers from the National Renewable Energy Laboratory found 15% average whole-building savings compared to single-pane windows. View full-size infographic. [PDF - 323 KB]
Reference above to any specific commercial product, process or service does not constitute or imply its endorsement, recommendation or favoring by the United States Government or any agency thereof.