Q. My windows are still in good condition, but are not the most efficient. To improve efficiency, security and provide safety during storms, I might install rolling shutters. What should I look for?
A. Adding rolling shutters on the exterior of windows improves efficiency and offers security and storm protection. I installed one over a large glass window in my family room. During a severe storm last fall, the shutter protected my window from a broken tree branch and me from flying glass had it broken. I have a wood burning fireplace in that room, so the shutter also saves energy during winter.
Energy savings from rolling shutters depends on the type of window glass and types of slat in the shutter. If your house has double-pane windows, adding the
shutters will about double the insulation value of the windows. With single-pane windows, the percentage increase in efficiency will be significantly greater.
An additional energy savings can be realized during summer because rolling shutters also block direct heat from the sun’s rays. The shutters can be lowered to any position to allow in only as much light (and heat) as you desire. When completely lowered over the window, they block nearly all light.
Rolling shutters are extremely strong and secure because they operate similarly to a rolltop desk. Narrow slats roll up into a box housing above the window. The ends of each slat slide in vertical tracks on each side of the window, making them secure and relatively airtight when fully closed. The slat itself provides insulation as does the dead air space created between the shutter and the window glass. In cold climates, this also reduces indoor window condensation problems.
If you want security and privacy along with light and ventilation, slightly raise the rolling shutter. The bottom of the shutter will not rise, but the slats will separate,
slightly exposing the interlocking flanges between them. Many shutters are designed with narrow slots in the flanges to allow natural light and fresh air through.
Several materials are used for the slats: roll-formed metal, plastic or extruded aluminum. All are suitable for most areas. Extruded aluminum slats are the strongest and most expensive, and are often used on shutters for large windows. Roll-formed metal ones can be filled with foam insulation for higher efficiency and rigidity. Check local building codes for required materials and strength.
Where there is limited space above the window to the roof soffit, install a rolling shutter with compact single-wall extruded slats. A 6-by-6-inch box housing can accommodate a compact-slat shutter up to 83 inches in vertical length. The same size box can handle only a 57-inch shutter with regular-size slats.
Shutters using double-wall, foam-filled slats made of 0.43mm gauge aluminum require a larger box above the window. These are good for energy savings year round. On south- and west-facing windows, select optional thermal reflecting paint. This is similar to the paint used on metal roofs for efficiency. It can keep the shutter and window 10 percent cooler than standard paint.
An important feature to consider is how the rolling shutter is opened and closed. Options are a pull strap, a strap crank, a crank handle or an electric motor. Keep in mind, if your shutters are inconvenient to use, you will not close them as often as you should for efficiency or security.
For smaller shutters up to 25 pounds, a pull strap is quick and inexpensive. A strap crank is functional for up to a 45 pounds. Large shutters and ones made from heavy-gauge extruded aluminum, up to 80 pounds, are easier to operate with a hand crank or an electric motor. Electric motor operators—some with automatic rain and heat sensors—are the easiest to install, but most expensive.
The following companies offer rolling window shutters: AC Shutters, (800) 745-5261, www.acshutters.com; Roll-A-Way, (877) 220-6663, www.roll-a-way.com; Rollac Shutters, (888) 276-5522, www.rollac.com; and Wheatbelt, (800) 264-5171, www.rollupshutter.com.