Green Product Selection Tool

How to Use the Product Selection Tool

  1. Choose the location.
  2. Choose whether your project is new construction or one of the three window replacement types. The effect of excessive air infiltration through existing operable windows is added to COMFEN-calculated energy savings for each replacement window comparison base case. Click here to review air infiltration calculation methodology and assumptions.
  3. Choose to see performance information by performing a Rank or Compare. Rank will order the performance results of a selected design condition returning results on annual energy, peak demand, carbon emissions, daylight, glare, condensation prediction, or costs savings compared to a generic double clear window (for new construction) or a generic single clear window (for replacement). Compare lets you choose 4 design scenarios to compare the performance between those scenarios.
  4. Visit for a detailed tutorial, or contact your Wausau market manager at,, or

Choose Location and Construction Type



Construction Type

The assumptions for the simulations are based on a perimeter zone model. Commercial buildings are divided into different thermal zones which can be served by different HVAC and lighting systems. The different spaces have different temperature and ventilation (outside air) requirements and often different operating schedules. The focus on the individual perimeter zones can then be generally applied to whole-building and site design. COMFEN, energy modeling software, was used to generate the results. COMFEN can help choose an energy-efficient and cost-effective window for a given application. It calculates heating and cooling energy use, peak heating and cooling demand, and visual and thermal comfort for specific window products. Updated information, future releases, and program information about COMFEN and other software tools (such as WINDOW, THERM, and Optics) from the Windows and Daylighting Group at LBNL can be found at