Energy & Cost Savings
The following information is an
example of energy and cost savings for Boston and Phoenix.
Heating
Season Savings
In climates with a significant heating season, windows have represented a major
source of unwanted heat loss, discomfort, and condensation problems. In recent
years, windows have undergone a technological revolution. It is now possible to
have lower heat loss, less air leakage, and warmer window surfaces that improve
comfort and minimize condensation. The graph below illustrates the significant
savings in heating season costs associated with energy efficient windows for a
house in a heating-dominated climate. In cold regions, this means that windows
are no longer an energy loser to be avoided -- increasing glazing area with high
performance windows can have little or no affect on total energy use.

Cooling Season Savings
In climates that mainly require cooling, windows have represented a major source
of unwanted heat gain. In recent years, windows have undergone a technological
revolution. It is now possible to significantly reduce solar heat gain and
improve comfort while providing clear views and daylight. The graph below
illustrates the significant savings in cooling season costs associated with
improved windows for a house in a cooling-dominated climate. In warm regions,
this means that high performance windows can face into the sun if desired
without great energy penalties -- although shading techniques remain important.

