What You Need to Know to Find the Perfect Windows

Hot And Cold: Upgrading Your Windows For Your Climate

Damaged, cracked or ill-fitting windows might seem like an annoyance at first, but from another point of view, they might just be an opportunity. The older your windows are, the more window technology has changed since they were installed. So rather than just replacing your windows with the same old thing, consider what window upgrades make the most sense for where you live.

Cold Climates: Glazing

A lot of heat is lost through windows when it's cold outside. The first step in preventing this is having windows and frames that fit well and don't allow drafts to steal the heat from inside; thick curtains can also help. But beyond that, the window glass itself can have a huge impact on how well a window holds in heat.

"Glazing" simply refers to the glass in the window; a single-glazed window has a single pane of glass within the frame. Double-glazing and triple-glazing, then, mean sandwiching together two or three panes of glass in a frame. The layer of air trapped between the panes of glass acts as insulation, slowing the transfer of heat from one side of the window to the other.

Of these glazing options, triple-glazing is the best at preventing heat loss. However, even with very thin panes of glass, the added weight of the extra pane can be a problem when replacing existing windows. A contractor or manufacturer like Doors/Windows Unlimited Inc can tell you whether triple-glazed windows would work for your home.

Cold Climates: Gas Insulation

Whether you install double- or triple-glazed windows, the space between the panes of glass in the window can be further insulated with inert, nontoxic gases. This involves sealing either argon, krypton, or a mix of the two into your windows.

Argon improves a window's ability to hold in heat over a fill of plain air. Krypton improves the thermal performance of a window even further, but is also more expensive. Krypton is also a popular choice for triple-glazed windows because it is effective even when the space between panes is very narrow.

Hot Climates: Coatings and Films

Films can be applied to existing windows or installed on new windows; factory coatings are applied on new windows. When choosing between them, keep in mind that installing films yourself (rather than having your window manufacturer choose and install films) may void your warranty, so be sure to check this first.

The purpose of films and coatings is to reduce the amount of heat that moves through the window. They are mainly used in hot, sunny climates to prevent your house from being overheated by the sun. When choosing a film or coating, then, you want one that will block heat without blocking too much light.

To check this, there are two values to compare: the SHGC (Solar Heat Gain Coefficient) and VT (Visible Transmittance). The ideal film or coating will have a higher VT than SHGC – that is to say, will let in more light than heat. Window coatings with a low VT, on the other hand, will appear visibly tinted and darken the interior of your home.