In most energy audits, replacing old windows with modern, double-pane, low-e units is an effective way to reduce energy loss, yet allow light in to bring in warmth in the winter and to reduce electricity use from artificial lights, particularly with workers around. The problem is that modern windows are usually fairly expensive, and therefore, have a longer payback than most other energy conservation measures. An alternative way to save money is to place a film inside your existing windows to improve insulation. Effective window film is usually made for clarity, tensile strength, and stability.

While window film can succeed in reducing fuel and electricity use, for a relatively cheap cost, be aware of the following items you may need to check pertaining to window film:

• Window integrity. Should your building have old, single pane windows, window film can enhance their insulation properties. However, window film cannot improve or cover over any structural deficiencies. If existing windows are cracked or if the surrounding brick needs upgrading, well, window film will not help. Before installing window film, make sure existing windows are inspected and upgraded should there be cracked panes or areas needing caulking.

• Drafts and pressure. Window film does not have the integrity of a window or a wall to keep out air, particularly from high winds or from high pressure differences. Before installing window film, make sure leaks are sealed and the building space is balanced. Anticipate air leakage during major wind events.

• Moisture. Window film is generally not effective at keeping moisture from moving, particularly in areas where window seals or frames are ineffective. Keep an eye out for condensation or other reasons for moisture buildup on walls, particularly on higher floors and in corners.

If your windows are not very old and of a strong structural integrity, window film may be a cost-effective way to improve energy efficiency and to allow workers to be more comfortable. However, if your building and its windows are old and damaged, it is critical to inspect all windows and to either invest in efforts to improve the structure of your windows (caulk or replace cracked pane) before installing window film or replace the windows altogether. It may be that a certain portion of your building has sustained more damage than others and window film can be more effective in certain parts than others.

CCES has the technical experts to help you assess your energy profile and develop and implement a variety of reliable energy conservation measures to save you energy costs, reduce maintenance, and make your staff more comfortable and productive. Contact us today at 914-584-6720 or at karell@CCESworld.com.