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Energy Efficiency

Energy-efficient, quality-assured windows from Window World of Houston have helped many Houston homeowners save money and energy year-round, and we can do the same for you!

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Table of Contents

Understanding Energy Efficiency

The Technology

Science Behind The Savings


white number 1 in green circleLow-E Glass

Low-E glass is brilliantly engineered to minimize the amount of UV rays and unwanted temperatures into your home.

white number 2 in green circleWarm-Edge Spacer

Intercept™ warm-edge spacer insulates the exterior edges of a sealed unit and can tack on 5% savings on monthly energy costs.

white number 3 in green circleVinyl Framing

Vinyl window frames are constructed with a complex array of compartments to help trap and repel unwanted weather.

white number 1 in green circleInsulated Structure

Built with rigid foam insulation to reduce energy loss and reinforce the siding for smoothness and straight lines.

white number 2 in green circleEnergy-Saving Barriers

High-density insulation to minimize outdoor noise for a quieter indoor ambiance and loss of wanted heat or air.

white number 3 in green circleBuilt to Last

Fully rolled over, double-thick nail hem anchors panels to the wall; tested to withstand harsh weather.


white number 1 in green circleInnovative Weatherstripping

Airtight weatherstripping seals the sides, top and bottom frames of your door to prevent air infiltration.

white number 2 in green circleInsulated Core

Insulated polyurethane core provides an additional thermal barrier.

white number 3 in green circleSturdy Frames

Composite frames resist rotting, rusting and warping to withstand constant exposure to the elements.

white number 4 in green circleEnergy-Saving Door Lites

Decorative and ENERGY STAR-compliant door lites that allow light in but keep the elements out.

The ENERGY STAR® Qualified SolarZone™ Insulated Glass Package Difference?

A window is 80% glass. The only way you’ll see substantial heating and cooling savings is to boost the glass performance. Window World of Houston helps you do that by combining UV-filtering Low-E glass (LG), insulating argon gas and the Intercept™ warm-edge spacer system to deliver superior energy efficiency. Combine, they can combat the harmful effects of the sun—no more worrying about faded carpets, curtains or furniture!

Low energy windows in the winter
In winter, a warmer glass temperature is maintained, increasing the R-value by an additional 104%.
Low energy windows in the summer
In summer, a 48% reduction in solar heat gain helps cut air conditioning costs.

An Inside Look

SolarZone™ Insulated Glass Package

How does Low-E glass (LG) work?

  • Reduces long-wave radiation to keep your home cooler in summer months
  • Allows solar rays into your home during the winter and blocks heat from escaping

How does the Intercept™ spacer system work?

  • One-piece metal alloy, U-channel design acts as a thermal barrier to reduce heat loss
  • One-piece design is better equipped to contain insulating gas than traditional designs
  • Helps keep glass surface much warmer than traditional spacer systems
  • Expands and contracts with changing temperatures for increased durability and reduced sealant erosion

How much energy can the SolarZone™ insulated glass package save you?

Our ComfortWorld Windows with the SolarZone™ insulated glass package can improve your home’s efficiency by a cumulative 35%.

What difference does Low-E glass make?

The window shown on the left is a clear insulated glass unit, and the window on the right is a Solarban® 60 Low-E insulated glass unit. Using thermography, you can clearly see the transmission of solar heat on the clear insulated glass window – indicated by the green, yellow and orange colors from the heat scale. When compared to the extremely low transmission of solar heat on the Solarban® 60 Low-E insulated glass unit, the best choice for your home is clear.

Thermography of window comparing standard clear insulating glass vs. Solarban® 60 insulating glass

Climate Requirements

Interested in Becoming ENERGY STAR® Certified?

ENERGY STAR is a government-sanctioned symbol for energy efficiency, credibility, sustainability and cost-savings for the consumer. Browse below to explore what’s required to become ENERGY STAR-certified and what it looks like in your region of the country.

Your Climate

U-Factor Requirements

U-Factor measures the rate at which heat flows through an object. The lower your U-value, the less heat your windows allow through them.

  • Northern: ≤ .27
  • North-Central: ≤ .30
  • South-Central: ≤ .30
  • Southern: ≤ .40

R-Value Requirements

R-Value determines how well the insulation inside your window is performing. The higher your R-value, the better insulated your window is.

  • Northern: 13 – 21
  • North-Central: 13 – 21
  • South-Central: 13 – 21
  • Southern: 13 – 21

Why You Need A High-Performing Insulated Product

Window World of Houston is located in ENERGY STAR’s Southern Climate category. To maintain certification here, our windows and doors must maintain a U-Value of ≤ .40 and an R-Factor from 13 to 21.

Glossary Of Terms

Energy Efficiency Terms You Need To Know

Low-E Glass

Low-E glass is a type of glass that has been treated with a microscopic, metallic coating designed to filter certain types of light into your home. The glass blocks heat gain from the sun’s reflected rays in warmer months and allows warmth from the sun’s shorter rays to flow into your home during cooler seasons.

Low-E glass can improve year-round energy performance by 24%

Warm-Edge Spacer System

Our Intercept™ warm-edge spacer system is a new-age technology used to extend the shelf-life of window glass by reducing condensation build-up and edge-to-glass temperatures. Designed to seal in escaping heat, this spacer system is the most effective of its kind.

By adding the Intercept™ Warm Edge Spacer System, you can increase the efficiency by yet another 5%.

Argon Gas

Argon is a colorless, odorless and nonreactive insulating property with extremely high density and extremely low thermal conductivity, making it an ideal agent for year-round comfort.

Argon glass filling – a better insulator than oxygen – can increase efficiency by another 6%

Make Your Home More Energy Efficient

Spending an excessive amount on your monthly utility bills is now a thing of the past. Window World’s energy-efficient windows are the smartest investment for any homeowner! Thanks to the substantial energy efficiency, our windows provide you and your family with year-round comfort, while keeping your monthly energy bills at an all time low. Ready to reduce your home’s energy consumption with energy-efficient windows? Learn more by watching the video to the left and start enjoying the many benefits of our energy-efficient windows by scheduling a free in-home estimate today!

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