Frequently Asked Questions

Window attachments are products such as shades, blinds, storm windows, solar screens and awnings that can be installed either inside or outside a window on a home or building. Window attachments can serve a variety of purposes, such as complementing the interior design of a room; enhancing views and natural light; reducing draftiness; reducing glare and heat from the sun; providing additional security; and increasing privacy. Most importantly, products with the AERC Energy Improvement label may improve the energy performance and comfort of your home.

Products with this label can help you save energy and make your home more comfortable. It also makes it easier for you to compare and select energy-efficient window attachments for your home by indicating a product’s energy performance in both a warm and a cool climate. All homes use energy, but when you buy products with the AERC Energy Improvement label, you can help your home use less of it. In some cases, you may see the language, “Not applicable for energy savings” in lieu of a rating. This means that the given product is not recommended for energy improvement in that particular climate.

Window attachments help regulate the amount of heat and sunlight that enters or exits your home, which can thereby reduce the need for heating when it’s cool outside and reduce the need for air conditioning when the weather is warmer. This type of enhanced energy performance can help your home save energy.

If you’ve ever felt a draft while standing near a window in your home, that means you’re likely losing energy due to cool air seeping in through your window (though you can also lose energy by warm air leaking out). The Cool Climate number – or rating – indicates the amount of energy that you can save by using the window attachment if you live in a cooler climate (where you turn on your heat most of the year), compared to not using a window attachment at all. In other words, if the window attachment you are interested in buying has a Cool Climate rating of 64, installing the attachment over an existing window in your home will save 64% of the energy that would otherwise be lost without the attachment. This means your heater can do less work! Put simply, the closer the Cool Climate rating is to the Max Improvement rating, the less energy you will need to keep your home comfortable when it’s cool outside. So, if you live in a climate that tends to be cooler throughout the year, this number is of most importance to you.

Often times, our windows aren’t sealed tight enough, which can allow cool air from your AC to leak out (or warm air to seep in), causing you to use more energy. The Warm Climate number – or rating – indicates the amount of energy that you can save by using the window attachment if you live in a warmer climate (where you use your air conditioning most of the year), compared to not using a window attachment at all. In other words, if the window attachment you are interested in buying has a Warm Climate rating of 64, installing the attachment over an existing window in your home will save 64% of the energy that would otherwise be lost without the attachment. This means your air conditioner can do less work! Put simply, the closer this number is to the Max Improvement rating, the less energy you will need to keep your home comfortable when it’s warm outside. So, if you live in a climate that tends to be warmer throughout the year, this number is of most importance to you.

The Max Rating number is the maximum energy rating that a product can have within its product category. Each product category (think: blinds, shades, shutters, storm windows) has a different Max Rating. In other words, if you live in a cool climate and are looking to buy new storm windows, the Max Rating you will see in that product category is 110, compared to blinds, which have a Max Rating of 15. The closer the product’s Cool Climate or Warm Climate rating is to the Max Rating listed, the greater the potential energy savings. To compare energy improvement across different product categories (i.e. storm windows vs. blinds), simply  compare the Cool Climate or Warm Climate ratings on each product label (depending on the climate in which you live).

While most of us experience both warm and cool temperatures throughout the year, it is important to consider which climate is most applicable to you. For example, if you live in the Northern United States, your focus should be on the Cool Climate rating – even if your home does get hot in the summer. The opposite is true if you live in the Southern United States. Although you may experience bouts of cooler temperatures throughout the year, your focus should be on the Warm Climate rating. For a few select regions, where heating and cooling needs are equal, it may be necessary to consider both ratings.

Certified window attachments can be found anywhere window attachment products are sold, including online retailers. To find the best energy-efficient window attachment(s) for your home, visit our Certified Products Search. The product search allows you to enter your product preferences and helps you find the window attachment product(s) that best fit your needs.

You can learn more by visiting:

• The U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE): The mission of EERE is to create and sustain American leadership in the transition to a global clean energy economy. Its vision is a strong and prosperous America powered by clean, affordable and secure energy (http://energy.gov/eere/office-energy-efficiency-renewable-energy).
• The Building Technology Office (BTO) of the U.S. Department of Energy: The BTO leads a vast network of research and industry partners to continually develop innovative, cost-effective energy saving solutions for better products, better new homes better ways to improve older homes and better buildings in which we work, shop and lead our everyday lives (http://energy.gov/eere/buildings/building-technologies-office).