Start with two ratings.
U-factor
U-factor describes heat transfer through a window. A lower number means better resistance to heat flow. Compare whole-window ratings for the specific configuration.
Solar Heat Gain Coefficient (SHGC)
SHGC describes how much solar heat passes through. Lower values admit less solar heat. Climate, orientation and shade all belong in the conversation.
Get to know ClimaTech.
Alside’s ClimaTech families combine Low-E glass, insulating gas and spacer technology. Package names and availability differ by product line and region.
- ClimaTech
- Low-E glass, argon and a warm-edge spacer.
- ClimaTech Plus
- Low-E glass with argon and a foam spacer system.
- ClimaTech PriME
- A triple-pane option with multiple Low-E surfaces and argon-filled spaces on eligible products.
- Other packages
- Elite, ThermD, TPS and Western options are product-specific. Consult the line’s current literature.
Check the exact configuration.
ENERGY STAR qualification is not a blanket promise for every window in a line. Verify the current criteria and rating for the selected model, glass and climate zone.
Sources: Alside insulated glass packages, Mezzo and Vero.
Common glass questions
Are all Alside windows ENERGY STAR certified?
No. Qualification depends on the exact window, glass package and climate zone. Check the current rating for your selected configuration.
Does triple-pane glass always make sense?
Compare the complete window’s ratings, available sizes, weight and price for your project. Pane count is one part of the decision.