Storm windows were created to protect a home’s primary windows from the elements, like wind, rain, sun, sleet or snow. But that was a long time ago, long before glass could be manufactured into large sheets.
A Little History
Much like humans, windows too have evolved over the years. Until recently, window manufacturers didn’t have the technology to make glass much larger than 4-inch x 3-inch panes. We are so used to seeing large pane glass windows these days that we forget about such humble origins.
Our first windows were made up of these smaller, individual pieces of single pane glass and held in place with putty and wood framing. Unfortunately, the elements were hard on these windows. Sun, rain, wind, snow-they all conspired to break down the putty, causing it to dry out and crack and eventually fall out. These windows required a lot of care and maintenance, for all the obvious reasons.
The concept of the “storm window” was born about the same time that sheet glass came into mainstream manufacturing. A storm window seemed to be the answer to every homeowner’s weather woes, hence their widespread use and popularity. A storm window protected the primary window from the elements, so the little frames of the primary window wouldn’t have to be re-puttied and repainted every year, a tedious and labor-intensive job to be sure.
A Lot of Science
Years later, with the energy crisis looming large, home construction booming, and energy costs soaring, the storm window was repackaged as an “energy-efficient” double pane window. True, it did add a layer of insulation. But we know better today. In comparison to today’s truly energy-efficient windows, that storm window is a poor substitute indeed.
Thanks to advances in window science, the storm window is no longer the homeowner’s answer to energy efficiency. On average, today’s window glass “package” is four times more thermal efficient than a single pane glass window with a storm window installed over it.
Windows are just smarter these days. A glass pane with transparent, low-e silver oxide coating acts as a reflective shield, keeping radiant heat from affecting your home’s temperature and comfort. A dual pane window filled with argon gas further reduces the amount of heat transfer because argon is denser than air, slowing down the amount of heat that can pass through the glass.
Frames made of engineered lumber, also known as composites, offer a low coefficient of thermal expansion, which means they don’t expand and contract like other frame materials, so their strength and durability are far superior. All these features combined, the newer maintenance-free, energy-efficient window packages are airtight. They can and should stand alone on their own merit. That’s why storm windows are truly obsolete.
In fact, installing a storm window over an energy-efficient window can do more harm than good. The intense heat buildup that can occur between the storm window and the primary window, especially during the hotter months, bakes the seals, affects expansion and contraction, and shortens the life of your energy-efficient primary windows.
Don’t risk your new windows by putting storm windows over top of them. Today’s windows don’t need the type of protection the storm window originally offered, and they definitely don’t need the additional insulation. Do yourself a favor and leave storm windows for the history books, a footnote in the fascinating story of window science.