Triple pane windows (also known as triple glazed windows) are windows with three layers of glass – outer, middle and inner. The middle layer is generally surrounded by an inert gas like argon or krypton (or sometimes a mixture), which is trapped by the outer and inner panes.
Benefits of Triple Pane Windows vs. Double Pane Windows
A triple pane window provides more insulation and is more energy efficient than the more common double pane window (or dual pane), not just because of the added barrier, but because this extra layer allows another surface to be given a low-emittance (Low-E) coating.
Essentially a Low-E coating hinders radiant heat transfer. Therefore, the temperature on the inside of your building is not affected much by means of the triple pane windows whether it is summer or winter, as very little heat will be lost from the inside or gained from the outside. This is one clear advantage triple panes have over double panes. (See Energy Efficiency of Triple Pane Windows – r value)
Another advantage of triple pane windows over dual pane, is that they do not attract as much condensation on the interior. (see Condensation and Triple Pane Windows). Also, generally speaking, triple panes will provide better insulation against sound or noise from outside. However, bear in mind that double panes can be just as effective(or close enough anyway), if the overall space between the inner and outer layers, and the thickness of the glasses are the same for the double and triple.
Drawbacks to Triple Pane Windows vs. Double Pane Windows
There are of course some drawbacks to triple pane windows, otherwise it would be the default for everyone. The main one is the cost. (See The Cost of Triple Pane Windows). Triple pane windows can be quite expensive when compared to double pane. One might argue that triple pane windows are an investment since the initial cost should be recovered in the savings attained from the low energy loss. However, practically speaking, the additional cost will not be recovered in the lifetime of the window. This does somewhat depend on where you live and how cold it gets. For those in the more extreme climates, it might work out to be more cost effective to get triple pane windows. Another drawback to triple pane windows is that the extra pane adds to the weight of the window, and this can have adverse effects to the structure of the building and the window itself, if the structure wasn’t built to accommodate this type of weight.
For the most part, triple pane windows can be considered a luxury, that gives added comfort. Whether or not they are worth it, will depend on what it is you are trying to effect. The more salient points of consideration have been highlighted here which should equip you to make an informed decision if you are contemplating going with triple pane windows.