Are 20 Year Old Windows Energy Efficient?

Mar 17, 2023

Energy-efficient windows provide homes with a variety of benefits, including helping to keep your home a comfortable temperature and keep the cost of utilities down. What about your existing windows? Are they energy efficient? If your windows are 20 years old, they may not be. Here’s how to tell if your windows are working as well as they should, and what to look for in replacement windows.

Are 20 Year Old Windows Energy Efficient?

Most windows have a lifespan of about 20 years. If your windows are that old, they are likely not as energy efficient as newer window options on the market. Older windows were often made with one pane of glass, which doesn’t insulate as well as two panes of glass with insulating argon gas in between. Single-pane windows are less effective at keeping heat outside during the summer and inside during the winter, which can cause your heating and cooling system to work harder to keep your house a comfortable temperature. This lack of efficiency also leads to higher energy costs. 

Old windows or windows that were original to the house may also have signs of wear, cracks, leaks, and other damage that negatively impacts the windows’ efficiency and allows outside elements to enter your home. Additionally, old windows may be difficult to open. If your windows are old and no longer working properly, it’s time to replace them. 

Signs Your Existing Windows Aren’t Efficient

How can you tell if your old windows are not very efficient? There are several signs you should look for. 

  • Uncomfortable indoor temperature: If your heating, ventilation, and air conditioning (HVAC) system is struggling to keep your house at the set temperature, your windows may be letting indoor air out, or outdoor air in. 
  • Rising energy bills: When windows aren’t efficient, your HVAC system has to work harder, which can cost you more money in energy bills. 
  • Drafts: If a window is shut but it still feels like air is coming through, your window is likely not functioning properly. Over time, the outdoor elements can cause old weathertight seals to weaken or fail, allowing air to enter your house.
  • Condensation: Condensation between the panes of glass is a sign that the weathertight seal is broken. When this happens, the insulating gas leaks out and moisture builds up between the panes. This negatively impacts the energy efficiency of your windows. 
  • Single pane: Old windows often have only a single pane of glass, whereas newer windows have two panes, making the new windows better at preventing heat from transferring into or out of your home.
  • Poor installation: If a window was not installed properly, it may not be working correctly and may allow the loss of heat or cool air from your home. 
  • Leaks: Cracks in a window can allow water to leak in, which can cause mold and mildew to grow. When cracks are present, air may be able to escape as well.

If you notice these signs, it may be time for window restoration or replacement. A consultation from a professional window installation company can help you decide which option is best for your home. If you live in an old house and the windows are old, replacement will likely be the better option. 

What to Look for When Replacing Windows

If you’re ready to replace your old or original windows with new windows, it’s helpful to look for specific features that increase the potential energy savings. For example, look for windows with a low-emissivity (“Low-E”) coating, which reflects heat. This coating also reflects UV light, helping to prevent carpets and floors from fading. Additionally, look for windows that have at least a 10 year warranty. These windows should last longer than cheaper ones with shorter warranties. It’s also helpful to look at the SHGC rating, ENERGY STAR rating, and the number of glass panes when choosing replacement windows. 

Solar Heat Gain Coefficient

Solar heat gain coefficient (SHGC) measures the fraction of solar energy that gets through a window. The rating is on a scale of 0 to 1, and the lower the number, the better the window blocks heat from the sun. Choosing a window with a low SHGC rating can help prevent excess heat from entering your house via the window, making your HVAC not have to work so hard to keep your home cool in hotter months. This can also help lower the cost of your energy bills. 

Energy Efficiency Rating

An ENERGY STAR rating indicates a product meets strict energy efficiency guidelines set by the US Environmental Protection Agency (EPA). Products with ENERGY STAR ratings are also manufactured by an ENERGY STAR partner and have been independently tested, certified, and verified by the National Fenestration Rating Council (NFRC). When looking for high-performing replacement windows, choosing windows with an ENERGY star rating can help ensure you’re getting quality, energy-saving products.  

Double Pane Windows 

When replacing old windows, opt for windows that have multiple panes of glass. While single-pane windows only have one layer of glass, double-pane windows contain two panes of glass with an insulating gas in between. These additional layers help protect your home from outdoor elements, support temperature control, and offer sound dampening effects. Replacing single-pane windows with double or even triple-pane ones can decrease your home’s energy use and increase your energy savings.

Benefits of Replacing Older Windows

Replacing windows offers a variety of benefits, including improved efficiency. New windows improve your home’s thermal insulation. This makes your HVAC not have to work as hard to keep your house a set temperature, which reduces your energy use and lowers the cost of your energy bills. For most homes, window replacement can lead to 15-25% energy savings over the span of one year. If you’re looking to “go green” and be more environmentally friendly, window replacement can be a great step.  

In addition to energy and cost benefits, installing new windows offers perks for your home’s appearance, safety, and usability. New windows improve your curb appeal by making your house look nicer and newer. Window replacement can also increase the value of your house, and you can typically recoup about 70% of your investment.

Some new windows can help protect your family from home intruders, such as styles that lock, cannot be opened from the outside, or that have other security features. New windows also reduce the amount of noise that comes through, so you won’t hear as much sound coming in from outside. 

Request Professional Window Installation

When it’s time to replace windows with newer, more insulating options, hiring professional window installers can help ensure your windows fit properly and function correctly. Look for a company that offers high-quality window products and installation by an experienced team. These factors will help extend the life of your replacement windows.

If you’re in the Columbus, Ohio area, contact McCloud Windows for beautiful and durable windows that can help reduce your energy costs and improve your home. All window products are installed by our factory-trained experts, so you can expect exceptional results. Contact us for more information about window replacement for local homes.