Different window types for energy savings

We've all been in situations where stepping around a structure's corner creates instant relief from driving rain or scorching sunlight, but the windows, walls and rooms of your home don't have the luxury of moving away from the weather.

Consider the following three factors that determine a window's energy-efficiency:

1. Climate: Identical homes in Rochester, NY, and San Jose, CA, need different window types to maximize comfort and savings. The San Jose home is efficient with insulated double-pane air-filled aluminum windows, while the Rochester home performs best with insulated triple-pane argon-filled fiberglass windows. Initial costs will be much higher for fiberglass, but monthly energy savings can be relatively similar.
2. Compass orientation: North-facing windows, in any climate, transfer cold inside more than south-facing windows in the same home. East and west facing windows may blast heat or cold into the house most of the day. South windows transmit less heat in summer, more in winter, which is ideal.
3. Size: An energy-efficient window transmits heat and cold more than surrounding well-insulated walls. The larger the window, the greater its thermal transfer. Make sure large windows are top-rated for your climate.

How comfortable interior rooms are depends on each of these factors, respectively. In most homes, there's no ""one type fits all"" solution to maximize total replacement windows cost.

Determining the best window types

Double-hung, single-hung, awning, casement, slider, fixed and hopper are types of windows that operate in ways that help compensate for climate, compass orientation, and size.

Even in drizzling rain, awning windows permit ventilation while keeping out moisture. Double and single-hung windows can increase natural ventilation if installed in opposite rooms. A north-facing fixed-pane view window can have short, wide sliders or awning windows at the bottom to keep out precipitation and allow ventilation. East and/or west-facing windows that permit small openings for ventilation, like double-hungs or sliders, are better than a side-hinged casement which cranks open on three sides.

But if strong prevailing winds are problematic, a casement can be cranked open to deflect them. Think creatively and analytically about each room's window requirements.

Choosing different window types won't create an architectural hodge-podge. Every type is available from country to contemporary. An awning window may look almost identical to a double-hung type. Factor in the above criteria for your true replacement windows cost and long-term comfort. Most importantly, study the ENERGY STAR label for its regionally tested ratings and for tax credits for windows installed by Dec. 31, 2011.

Sources

Andersen Windows • Window Types 

ENERGY STAR • Qualified Windows

Efficient Windows Collaborate • Window Selection Tool

About the Author

Suzanne Clemenz designed her passive solar home and remodeled two others. She worked with architects and contractors on floorplans, electrical, painting, windows, flooring installations, flood prevention walls and stonework, major drainage issues, an irrigation system and landscaping.