Understanding Window Energy Efficiency Ratings

A Homeowner’s Guide to Choosing the Best Energy-Efficient Windows

When shopping for replacement windows, understanding energy efficiency ratings can help you make an informed decision. Energy-efficient windows reduce heating and cooling costs, improve indoor comfort, and increase home value—but with so many ratings and certifications, how do you know what to look for?

This guide breaks down the most important window energy ratings, explains how they affect performance, and helps you choose the right windows for Indiana’s climate.

Key Window Energy Efficiency Ratings Explained

When comparing window options, you will see several different energy ratings on labels from organizations like ENERGY STAR® and the National Fenestration Rating Council (NFRC). Each rating measures a different aspect of energy performance.

1. U-Factor (Insulation Value)

What it means: Measures how well a window prevents heat from escaping.

• • Lower is better (ranges from 0.20 – 1.20)
  • Ideal for Indiana’s cold winters, where insulation is key

2. Solar Heat Gain Coefficient (SHGC)

What it means: Determines how much solar heat the window allows inside.

• • Lower SHGC blocks heat (best for hot climates)
  • Higher SHGC captures heat (better for colder climates)
  • A balanced SHGC is ideal for Indiana, preventing overheating in summer while keeping warmth inside in winter

3. Visible Transmittance (VT)

What it means: Indicates how much natural light passes through the glass.

• • Higher VT means a brighter interior with more natural light
  • Lower VT reduces glare and UV exposure

4. Air Leakage (AL)

What it means: Measures how much air can pass through small gaps in the window.

• • Lower is better (reduces drafts and energy loss)
  • Proper installation plays a big role in reducing air leakage

5. Condensation Resistance (CR)

What it means: Rates how well a window resists moisture buildup and mold growth.

• • Higher CR means better moisture resistance
  • Important for high-humidity areas like basements

6. ENERGY STAR® Certification

ENERGY STAR® certified windows meet strict energy-efficiency standards for different climate zones. Choosing ENERGY STAR® rated windows ensures better insulation, lower utility bills, and long-term savings.

How to Choose the Right Energy Ratings for Your Home

Choosing the right energy-efficient replacement windows depends on Indiana’s climate, which experiences hot summers and cold winters. Here is what to look for:

• • Low U-Factor (0.30 or lower) to prevent heat loss in winter
  • Balanced SHGC (0.25 – 0.40) for year-round comfort
  • Low Air Leakage (AL) for a draft-free home
  • High Condensation Resistance (CR) to reduce moisture issues
  • ENERGY STAR® Certification for maximum efficiency

Not sure what’s best for your home? Our experts can help you choose the perfect energy-efficient windows.

Our Energy-Efficient Windows: Quality You Can Trust

At Central Indiana Window & Door, we install Alside Mezzo® and Fusion® windows, engineered for superior insulation, durability, and energy savings.

Why Homeowners Choose Our Windows:

• • ClimaTech® Insulated Glass – Low-E coatings and argon gas for maximum efficiency
  • Fusion-Welded Vinyl Frames – Provides superior weather resistance
  • Warm-Edge Spacer Systems – Reduces condensation and improves insulation
  • Multiple Customization Options – Choose your style, grid patterns, and finishes

Professional installation is just as important as the window itself. Our factory-trained installers ensure a perfect, airtight fit for maximum performance.

Visit Our Showroom to See Energy-Efficient Windows in Person

Choosing replacement windows is an investment, and seeing the quality firsthand can make a difference. At our Lebanon, IN showroom, you can:

• • Compare frame materials, glass options, and energy efficiency ratings
  • Speak with window experts about the best options for your home
  • Test the smooth operation of our Alside Mezzo® and Fusion® windows

Showroom Address:
605 W South St, Lebanon, IN 46052

Stop by today or schedule an appointment to explore your options.

Proudly Serving Central Indiana

We provide energy-efficient window installation throughout Central Indiana, including:

• • Lebanon
  • Zionsville
  • Frankfort
  • Brownsburg
  • Danville
  • Westfield
  • Carmel
  • Noblesville
  • Fishers
  • Indianapolis
  • And surrounding areas

Our team understands local building codes and climate needs, ensuring you get the most efficient windows for your home.

Contact Us for Expert Window Replacement Advice

Understanding window energy ratings can feel overwhelming, but you don’t have to figure it out alone. Our trusted, BBB-accredited team is here to guide you.

• • Need help choosing the right energy-efficient windows?
  • Have questions about ENERGY STAR® ratings and insulation?
  • Want a free estimate on window replacement?

Call us today (765) 859-5066 or request a free consultation. We are happy to help.