Plastic Window Coverings: Energy-Saving Solution Or Gimmick?

Plastic window insulation is a popular method for improving the energy efficiency of a home. However, its effectiveness has been questioned, with some arguing that it does little to improve insulation and may even increase energy costs in the summer months. EnergyStar.gov rates plastic over windows as only 2 out of 5 stars for saving energy and money, suggesting that other methods, such as attic air sealing, may be more effective. Nevertheless, window kit manufacturers claim that energy savings may be more significant than homeowners experience, and some believe that plastic window insulation can reduce energy use by up to 50%.

Energy savings

Plastic over windows is rated only 2 out of 5 stars for saving energy and money by EnergyStar.gov. Window kit manufacturers claim energy savings may be more dramatic than homeowners actually experience. Whole-house air sealing can reduce your energy use by up to 30%, and this percentage increases when you pair air sealing with insulation and HVAC upgrades.

The effectiveness of plastic over windows depends on the quality of the windows. If the windows are old, the glass packs are clear, and the double-insulated units do not have Low-E film to deflect the sun's rays, then plastic will not make much difference. In fact, in the summer, hot and humid air will enter your home, triggering your central air or AC unit and making your energy bills soar.

However, if your windows are very drafty, then plastic over windows could save you more energy. Starting with the assumption of 50% savings, this would imply that the windows are very leaky and letting a lot of air pass.

Energy bills

According to Energy Star, a government program launched by the Environmental Protection Agency (EPA), sealing up leaks throughout your house with plastic can cut your utility bills by up to 20%. This means you could save up to $20 per window per winter, depending on your furnace type and location.

However, it's important to note that the effectiveness of this method may vary. EnergyStar.gov rates plastic over windows only 2 out of 5 stars for saving energy and money. Some manufacturers of window insulation kits may overstate the potential energy savings.

Additionally, while plastic over windows can help reduce heat transfer and keep your home cool during the summer, it is not as effective as other methods such as whole-house air sealing, which can reduce your energy use by up to 30%.

Overall, while putting plastic over your windows may not drastically reduce your energy bills, it can still help to conserve energy and save you some money, especially when combined with other energy-saving measures.

Solar heat gain coefficient

The solar heat gain coefficient (SHGC) is a measure of how well a window blocks heat from sunlight. The lower the SHGC, the better the window is at blocking heat from sunlight. Older windows that are 15 years or older tend to have a higher SHGC because they lack Low-E film that deflects the sun's rays.

Window kit manufacturers claim that putting plastic over windows can help save energy and money. However, EnergyStar.gov only gives plastic over windows 2 out of 5 stars for energy and money savings. This is because the plastic does not add much to the insulating properties of the window. In fact, in the summer, the hot and humid air can seep into your home, constantly triggering your central air or AC unit and causing your energy bills to soar.

Argon gas

Plastic over windows is rated only 2 out of 5 stars for saving energy and money by EnergyStar.gov. However, some people claim that it can save up to 50% of energy use.

One of the reasons plastic over windows may not be very effective is that it does not have the same insulating properties as argon gas. Argon gas is used in double-glazed windows to improve their insulation. The gas is inserted between the two panes of glass, creating an insulating barrier that helps to keep the cold out and the heat in during the winter months. It also helps to reduce the amount of heat that enters the building during the summer, keeping it cooler.

Insulation

Plastic over windows is rated only 2 out of 5 stars by EnergyStar.gov for saving energy and money. This is a low rating when compared to other methods of insulation, such as attic air sealing, which is rated 4 out of 5 stars. Window kit manufacturers claim that energy savings may be more dramatic than homeowners actually experience.

Whole-house air sealing can reduce your energy use by up to 30%. This percentage increases when you pair air sealing with insulation and HVAC upgrades.

The effectiveness of plastic over windows depends on the quality of the windows. Older windows that are 15 years or older are unlikely to be double-glazed and are unlikely to have Low-E film that deflects the sun's rays. They also won't have argon gas in the double panes inside the glass unit itself, so they won't insulate the cold.

The implication of using plastic over windows is that the windows are very leaky and letting a lot of air pass. Even a new window with insulated glass would not be expected to make that big of an impact based solely on the insulation value of the glass assembly.

Frequently asked questions