Storm windows are
window
A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent mat ...
s that are mounted outside or inside of the main glass windows of a house.
Storm windows exist in
North America, but are uncommon in continental Europe, where
double, triple or quadruple glazing is prevalent. Storm windows can be made of glass, rigid plastic panels, or flexible plastic sheets; and may be permanently or temporarily mounted. They function similarly to
insulated glazing
Insulating glass (IG) consists of two or more glass window panes separated by a space to reduce heat transfer across a part of the building envelope. A window with insulating glass is commonly known as double glazing or a double-paned window, ...
. The term may also refer to a small openable flap found in the side window on light aircraft.
In the United States, the older style of this window is often referred to as a "storm sash".
On modern houses they serve on existing windows in order to improve their thermal insulation
and
soundproofing. Aside from insulation, storm windows provide an additional measure of protection for homes against damages to costly glass panes during inclement weather such as hail. On older houses, storm windows were installed in autumn when window screens were removed. Later units combined the storm and screen pieces. Similarly,
storm doors (also called "screen doors") allow similar energy savings with less efficient primary doors – and allow a screen for summer ventilation.
Energy upgrade
Modern storm windows are a typical energy upgrade solution for cold climates. They are mostly intended to improve the insulation value (
R-value) of existing windows, especially single-glazed units.
Advantages and disadvantages
Storm windows can be very cost effective in cold climates. They are inexpensive, and can reduce heat loss by up to 50%, increasing the building's comfort and reducing the heating costs, which is difficult to achieve with inexpensive replacement windows.
They can also reduce exterior air infiltration significantly. Storm windows are an inexpensive add-on: even the best storm windows - three track exterior windows with
low-E glass – will cost a small fraction of the price of standard replacement windows.
Interior storm windows can produce problems of condensation and be visually obstructive; exterior storm windows can have a negative visual effect.
The negative visual effect can be minimized by using single line storm sashes. Condensation problems can be avoided by incorporating vent holes and a sealed fit.
"Testing the energy performance of wood windows in cold climates"
PDF, A Report to The State of Vermont Division for Historic Preservation
Types
A plastic PVC interior storm panel is particularly inexpensive and easy to install but these panels lose quality over time and may get broken quite easily. Storm windows with Low-E glass and metal frames are a more durable choice, and can provide better insulation.
Manufacturing process and applications
There are several laminated glass manufacturing processes:
The first method utilizes two or more pieces of glass bonded between one or more pieces of plasticized polyvinyl butyric resin using heat and pressure.
The second method uses two or more pieces of glass and poly-carbonate, bonded together with aliphatic urethane inter-layer under heat and pressure.
The third type of laminated glass is interlaid with a cured resin.
Each manufacturing process may include glass layers of equal or unequal thickness.
See also
* Storm cellar
A storm shelter or storm cellar is a type of underground bunker designed to protect the occupants from violent severe weather, particularly tornadoes. They are most frequently seen in the Midwest ("Tornado Alley") and Southeastern United States ( ...
* Storm door
* Storm drain
* Storm room
* Storm shutter
References
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Windows