All About Storm Windows

It's getting to be that time of year again. Time to think about storm windows, from Chapter 4 of "The Energy Savers Handbook":

"Storm windows, if properly installed, can reduce heat loss through single-glazed windows by lowering the Uvalue and reducing air leakage. Storm windows can be mounted either on the inside or outside of the existing window. The choice between interior and exterior storm
windows is largely one of personal preference and cost.

"From an energy standpoint, they perform about the same but an interior storm window, if the existing window is still an effective weather barrier, can reduce condensation more effectively than an exterior storm window. Tight-fitting old-style wooden storm windows perform slightly better than the modern aluminum-framed combination storm/screen storm windows. This is because aluminum is a poor thermal insulator. Your house may have old-style wooden storm windows, either in use or Figure 4-7- Storm windows can be an effective
substitute for purchasing new windows if the existing window is still in good condition.

"Storm windows must be of good quality, installed properly, and have low-E glass.
stored away in the attic or basement. If so, they can provide important energy savings. The problem with these old-style windows (and the reason they're never used in new construction) is that putting them up every fall and taking them down every spring is a lot of work, particularly on a multi-story house.

"When buying new storm windows, look for quality windows with low-E glass and good workmanship. Vinyl storm windows, with lower heat loss through the frame than aluminum, are now available. Be sure to properly install storm windows and seal them effectively where the
storm window frame meets the existing window frame. Be careful not to seal the weep holes.

"It is important to examine the cost-effectiveness of purchasing storm windows. Sometimes their lower cost relative to new energy efficient windows will not justify the reduced convenience, energy savings, and home improvement value.

"Interior storm windows, sometimes referred to as "energy panels," are generally easier to install than exterior storm windows. They may be made of glass or various types of plastic. Shrink-to-fit plastic film for making temporary interior storm windows is available at many
hardware and building supply stores. This last option is the least expensive for one-time use, but generally undesirable for homeowners. The shrink-fit windows are mainly attractive to renters, who want to reduce their energy bills without paying for permanent improvements to their landlord's property.

"Always remember: your home is a system. If you do not correctly adjust and seal your storm windows when the seasons change, they might as well not be there."

From Chapter 4 of The Virginia Energy Savers Handbook 2008: Department of Mechanical Engineering of Virginia Tech Blacksburg, VA 24060