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window replacement

About Andersen 400 series

Andersen is most famous and respected for their 400 series product line, which is the series Zulo will provide and install for you. The 400 series has composite windows and vinyl windows with a wood core. This solid wood core is protected and fully wrapped by a vinyl extrusion which prevents wood rot. A wood core creates, strength, longevity, and energy efficiency. Many products in today's marketplace are vinyl with a foam core, which tends to bend, bow, break seals, and cause operation issues. Having a wood core creates a rigid, well insulated product that will not bow or break over time. See diagram below for a good comparison between all products within the marketplace.

Are Andersen windows good? These have a solid wood core that is protected and wrapped by a seamless vinyl extrusion which prevents water from getting inside, making it rot proof. These windows do not warp because of the inflexible wood core and will operate smoothly without seal failures. The vinyl wrap prevents color fading more than any other material on the market because the color exists throughout the material, unlike surface applied paint. Vinyl and wood are both non-conductive, which means these windows are energy efficient and warm to the touch in the  winter.

Are vinyl windows good? Vinyl is completely maintenance free. Often times these windows will have either an insulated foam core or a fiberglass reinforced core. Vinyl is resistant to color fading. Since vinyl is plastic, without a solid wood core they expand and contract in the heat and cold, causing warping to occur. This frequently results in drafty, stuck, and hard to open windows. When the frame warps, pressure is applied to the seal of the glass and can cause seal failures. When the seal breaks the glass fogs up and you can no longer see out the window.

Are fiberglass windows good? These usually consist of an insulated foam core. Fiberglass is a strong material and does not tend to warp. Usually the stronger the material, the more conductive it becomes. In the winter these fiberglass frames will become cold and could frost up. As a result, they are not energy efficient because of the frame material alone. The insulated core does not help much with energy efficiency because the frame material is still conductive. Fiberglass products tend to fade more than any other product since the color is only applied to the surface.

Are aluminum clad wood windows good? Wood windows look very attractive. Wood is a great insulator and will result in high energy efficiency. These wood windows are cladded with aluminum on the exterior. Water tends to run down the glass, seep in between the aluminum and the glass, trapping the water against the wood and causing it to rot. The wood rot typically occurs on the bottom sash where the water accumulates. The aluminum cladding scratches easily, dents easily, becomes chalky and powdery over time, resulting in color fading.



Double hung  (up and down)


Casement  (crank out)

vinyl + wood core

The 400 series also has composite windows made of Fibrex, an Andersen exclusive patented technology which is comprised of both wood fibers and a polymer. The wood fibers are individually encased with polymer, which prevents wood rot, and the polymer is stabilized by the wood which prevents expansion and contraction. See pictures above showing a composite double hung (up and down) window and a vinyl wood core casement (crank out) window. See video below for more information on Fibrex! Andersen branded windows are one of the most reputable brands in Chicago.

Aluminum clad




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