High Performance Replacement Windows

The U.S. EPA promotes the use of high-energy efficient technologies, materials and equipment in homes and commercial buildings.  Homes and buildings with energy efficient high performance windows and doors use at least 30% less energy than homes built to meet the national Model Energy Code while maintaining or improving indoor air quality. Since windows and patio doors are such a large percentage of any home or commercial building’s “envelope,” there can be no doubt that replacing old, low performance windows with high performance Vinyl windows and patio doors will make a significant difference in the energy savings and comfort performance of your home or commercial building.  So, exactly what does this “high performance” mean and what are the benefits?

To start with, windows and patio doors typically comprise 10 to 25 percent of the exterior wall area of a home. Research studies report that windows in heating-dominated climates account for up to 25 percent of a typical house’s heating load and in cooling-dominated climates, windows account for up to 50 percent of the cooling load.

At Jantek, we design and manufacture only high performance vinyl EnergyMiser windows and patio doors. With over 28 years in the window and patio door industry, we have perfected our craft and our expertise.  This has resulted in our development of our EnergyMiser Technology which has put our windows and patio doors at the forefront of high performance and energy saving window and door products on the market today.  These technologies include improved framing materials, low-emissivity and solar control coatings, low-conductance gas fills, improved thermal breaks and warm edge spacers, and better edge sealing techniques. These technologies can be used independently or in combination, but must be selected based on climate to optimize performance. Read on for a thorough understanding of this important criteria in your decision process.

Windows can improve the thermal performance of homes by minimizing heat loss in heating-dominated climates and by minimizing solar heat gain in cooling-dominated climates. Thus windows with lower U-factors or higher R-values perform better in heating-dominated climates and windows with lower solar heat gain coefficients (SHGC) perform better in cooling-dominated climates. SHGC is a measure of the amount of solar energy that the glass in your window or patio door allows to pass. For a better understanding of SHGC, U-Factor and other important window performance criteria, take a look at our article on How To Compare Energy and Comfort Performance Of Window And Patio Door Brands.

The materials and the frame design also influence thermal performance. Low conductance materials, (the least conducting being vinyl), will conduct or transfer heat at a slower rate. This is followed wood and fiberglass, which performs better than high conductance materials such as aluminum or steel.  That means that the summer’s heat will transfer more slowly from outside to inside and, the heat generated from your heating system will transfer more slowly from inside to out.  If you must use metal windows, then look for “thermal breaks” in the window design in heating-dominated climates to avoid condensation and at least some reduction to thermal transfer.

Air tightness is another important consideration. Windows are now being tested and rated for air tightness. A rating of 0.2 cfm/ft (cubic feet per minute of air leakage per linear foot of window edge) or lower is considered good.

An effective building envelope is a key element for an energy-efficient home and your comfort. Replacing old drafty, energy leaking windows with high performance windows can improve the effectiveness of the building envelope and improve comfort.

High-performance vinyl replacement windows can provide many benefits including:

Improved comfort. High-performance vinyl replacement windows reduce conductive heat losses and gains resulting in warmer interior surfaces during the winter and cooler interior surfaces during the summer. In homes, approximately 40 percent of our physical comfort is due to the radiant heat exchange between our bodies and the surrounding interior surfaces. Thus, high-performance windows improve comfort by reducing this radiant heat exchange. In addition, improved frames reduce drafts and provide more consistent temperatures throughout the house.

Quieter home. High-performance vinyl replacement windows often utilize multiple glazing and insulated frames. These features reduce unwanted noise from the outside.

Increased quality. High-performance vinyl replacement windows are often constructed with better quality materials that can result in stronger, easier to operate, and longer lasting windows. As a result of these improvements, manufacturers frequently offer extended warranties on these products.

Improved indoor air quality. High-performance vinyl replacement windows and patio doors often have air tightness ratings of 0.2 cfm/ft or less which reduce the amount of unconditioned air leakage into a house. This air leakage can bring in dirt, dust, and other impurities that can negatively affect indoor air quality.

Lower utility bills. High-performance vinyl replacement windows and patio doors are better insulated and more air-tight. These features reduce energy consumption for heating and cooling

which results in lower utility bills, making homes less expensive to operate.

Reduced obsolescence. Based on recent trends for improved efficiency, high-performance vinyl windows and patio doors are expected to become standard practice for the building industry, therefore homes with high-performance windows are, therefore, expected to be less vulnerable to obsolescence.

Fewer condensation problems. High-performance windows stay warmer in the winter resulting in drier windows with fewer condensation-related problems. Condensation can stain fabrics, lead to mold and mildew build-up, and in cold climates cause damage due to the freeze/thaw cycle.

Reduced wear on home furnishings. Low-E coatings can block up to 98 percent of the ultraviolet radiation emitted by the sun. This radiation causes window treatments, flooring, and furniture to fade and wear faster.

Improved resale position. High-performance windows can provide the many impressive benefits  resulting in a more comfortable, quieter, higher quality home with lower utility bills and fewer condensation and fading problems. These benefits can translate into higher resale value.

So hopefully I have given you a better understanding of the quality dimension of your replacement window and patio door project. This is just one piece of the total picture. We address more of the pieces in our other blog articles so check them out.