Question: As a member of the hotel industry trying to identify energy-saving opportunities, I’m wondering if the windows of my building have any effect on my my energy costs?

Answer: That’s a good question, with a not-so-simple answer. The short answer is yes- the windows of your hotel, like those of any retail space or restaurant, can seriously impact the amount of money your business spends on energy.

Basically, there are two things to take into consideration; daylight and solar radiation. During the summer months, while daylight can help drive energy-costs down by providing natural light at no cost, too much solar radiation can cause things to heat up pretty fast, which means that you inevitably have to find a way of cooling things down. In the wintertime however, while you’ll want to store up on daylight, proper insulation is necessary to ensure that you’re not heating costs don’t skyrocket when the cold sneaks in.

To help answer your question, let’s take a quick look at a few ways you can work with your windows to make them more efficient so you can save money on energy.

Seal your way to savings

According to Energy Star, it is important to create a “building envelope” outside your restaurant, hotel or retail space. This includes the use of awnings, overhangs, light shelves and windows with low solar heat gain coefficient (SHGC) to help reduce the amount of solar heat that gets through while allowing for daylight to shine in.

Whatever you do, do not believe that blocking out daylight is the answer to your energy problems just because it has a tendency to heat things up. Daylight does, after all, provide your business with free natural light, offering huge energy-saving potential. Consider using daylight-harvesting sensors to adjust the interior lighting levels in your restaurant, shop, or hotel suites depending on the intensity of natural light coming through.

Make use of window films, screens and shades

According to the Green Lodging News, window film is one of the most-cost effective choices for energy savings in retrofit applications in existing hotels or retail spaces. That could be because window film typically offers a payback time of less than two years, or a 70% return on investment and are a great way to reduce harmful UV rays and minimize glare on television and computer screens throughout your work space.

From the looks of things, many businesses have already caught on to the potential of window film and are charging full steam ahead with the installation. As reported in the Environmental Leader, the Hyatt Regency Century Plaza in Los Angeles recently upgraded more than 78,000 square feet of its windows with an energy-efficiency product made by Solar Gard, whose window films supposedly reject up to 79% of solar energy download  their commercial brochure).

For hotels or retail spaces located in climates with long cooling seasons like Canada, the U.S Department of Energy (DOE) recommends using high-reflectivity films for optimizing energy efficiency. As a general rule in fact, reflective, silver, mirror-like films are typically more effective than the colored, more transparent ones that filter solar radiation instead of reflecting it; both however, are most effective on east and west facing windows.

Finally, as obvious as it may seem, window shades can be  a great way to save on energy; and dual shades, are even better. Dual shades are highly reflective on one side and heat absorbing on the other – perfect for Canada where sides can be rotated to fall in line with the seasons. If you choose to install windows shades, remember that they should be mounted as close to the window glass as possible with the side of the shade close to the wall in order to seal the air space. Lower the shades on sunlit windows in the summer and, for south-facing windows, raise the shade during the day to generate additional daylight heat.

It’s all about how you frame it

Do you know what the thermal resistance of your window frames are? Since aluminum or metal frames conduct heat rapidly and wooden frames expand and contract in response to varying weather conditions, it is best to choose a window frame made with vinyl, wood, fiberglass or composite frames made of particleboard and laminated strand lumber.

There’s lots more to know about window frames, glazing,  glass, tints, coatings and more! Additional information can be found via the website of the DOE, the Efficient Windows Collaborative, and NRCan (Natural Resources Canada).

For a list of terminology useful for understanding window film and more, visit the International Window Film Association.

Questions or comments about how your windows can impact energy costs? Leave them below!

image credit: W Worldwide