How do you know if your home’s windows need to be replaced? Well, the most important factor in making that decision is determining whether the new, replacement windows are significantly better than the ones you already have.
What if you have old, single-pane aluminum windows? If that’s the case, you probably already know that you would benefit greatly from replacing them, and here are a couple of reasons why.
The Problem of Heat Transfer and Aluminum Windows
Aluminum is a material with properties that conduct heat or encourage heat transfer. For example, when you put warm aluminum cans into a cooler filled with ice, the heat inside the cans quickly escapes, cooling the liquid inside. This is because the aluminum material has a very high heat transfer coefficient, quickly and efficiently changing the temperature. While that is great news for your drinks, it is not so great when the same happens with your home's old aluminum windows.
If you have aluminum windows in your home, go up and touch the frame of one of them. If it is a hot day, the frame will feel warm inside, even if the temperature in the house is cool. If your house is warm and cool outside, you may feel a draft because heat is escaping. Undoubtedly, your expensive energy bill has already shown you the result of this heat transfer. For more information, see our blog post on Understanding the Thermodynamics of Windows.
Aluminum Windows and Condensation
One of our Southwest Exteriors clients decided to replace their windows in stages, so they currently have one newly replaced window. In contrast, most of their windows are still single-pane aluminum. One evening as occasionally happens in San Antonio, the temperature dropped extremely rapidly outside. This fast temperature change caused condensation to form on the inside of every single window in the house, except for the replacement window. The aluminum windows were cold to the touch, but the replacement window remained at room temperature, completely unaffected.
Are aluminum windows still popular?
According to a report by the National Association of Home Builders (NAHB), the market share by material of new construction windows in the United States in 2021 was as follows:
Vinyl windows have been gaining popularity recently due to their low cost, energy efficiency, and low maintenance requirements. Wood windows remain popular among high-end home builders and homeowners who value their natural beauty and traditional aesthetic. Fiberglass windows are also gaining in popularity due to their durability, energy efficiency, and ability to mimic the look of wood. Aluminum windows have fallen out of favor in recent years due to their poor energy efficiency and tendency to conduct heat, which can lead to condensation and frost on the glass.
Do aluminum windows meet Energy Star requirements?
Aluminum windows can meet the Energy Star code, depending on the specific product and how it is designed and manufactured. Energy Star is a certification program that sets energy efficiency standards for various products, including windows. To qualify for Energy Star certification, windows must meet certain performance criteria for factors such as U-factor, solar heat gain coefficient (SHGC), and air leakage.
Aluminum windows have historically been known for their poor energy efficiency, as aluminum is a highly conductive material that allows heat to transfer easily through the frame. However, window design and technology advances have led to the development of more energy-efficient aluminum windows. Some manufacturers offer aluminum windows with thermal breaks and insulating materials inserted into the frame to reduce heat transfer. Other manufacturers offer aluminum-clad wood windows with an aluminum exterior and a wood interior, providing the durability and low maintenance of aluminum with the natural beauty and insulation of wood.
If you're considering aluminum windows for your home, look for products that meet Energy Star criteria for energy efficiency. The Energy Star label can help you identify windows and performance glass that will save you money on your energy bills and help reduce your home's environmental impact.
So, because single-pane aluminum windows are extremely inefficient, you would certainly benefit from replacing them with better windows. In fact, because of new energy efficiency standards in Texas, single-pane aluminum windows are no longer available to consumers. The newer aluminum windows are double-paned and marketed as having “thermal breaks.” These thermal breaks are a piece of non-conductive material (plastic, for example) that is put between the aluminum layers to stop heat transfer. Choosing a high-quality window material frame and coupling it with energy-efficient double-pane glass will transform your energy bill and stop overworking your air conditioner and heater to maintain pleasant temperatures inside. If finances prevent you from doing your whole house at once, then replacing your aluminum windows in phases is an option. We recommend replacing windows together in the same location so that you don’t end up with two very different-looking windows right next to each other.