Your Windows & Energy Efficiency

Part I: What the Experts Say About the Value of Energy Efficient Windows

Windows provide our homes with natural light, warmth, and ventilation. While they are meant to offer these benefits, they can also affect your home’s energy efficiency negatively – particularly if you do not have an idea of how energy efficient they can be.

Indeed, you can reduce your utility costs by installing high-performance and high efficiency windows. You can also apply improvements and updates to your existing ones. To get you started, check out what the experts and professionals say about energy efficient windows.

The Value and Benefits of Energy efficient Windows

When you get energy efficient windows, you enjoy all of their fundamental advantages plus a host of other valuable benefits. Here is a list of those perks as given by the Efficient Windows Collaborative (EWC). EWC is a nonprofit 501(c)3 organization that partners with window, door, skylight, and component manufacturers, research organizations, federal, state and local government agencies, and others interested in expanding the market for high-efficiency fenestration products.

• Increased Light & View

Windows provide natural daylighting and nice outdoor views but they can also be a source of unwanted heat and damaging UV rays. Fortunately, newer products let you keep the blinds up against heat transfer through features and applications that prevent the negative effects. For instance, windows with low-emissivity coating reflect away harmful UV rays and reduce – if not totally eliminate – solar heat gain, while increasing visible light transmittance.

• Energy & Cost Savings

In areas that mostly require heating, high-performance windows can help prevent unnecessary heat loss and condensation issues, and make the home more comfortable. Meanwhile, in locations where cooling is the most concern, energy efficient windows can decrease unwanted heat gain. In both scenarios, energy efficient windows can reduce annual energy expenses associated with heating and cooling your home.

• Lowered HVAC Costs

Energy efficient windows help decrease peak heating and cooling loads, your home’s maximum heating and cooling requirement. These dictate the size of HVAC equipment – including furnaces, heat pumps, fans, and air conditioners – that must be installed in the home. Therefore, when peak loads are reduced, you can opt to acquire a smaller HVAC system which costs less initially and uses less energy.

Selecting New Energy efficient Windows

If your home has old and inefficient windows, getting new and energy efficient replacements is advised. The U.S. Department of Energy (DOE) recommends that you consider the following factors:

• Design, Material, and Composition. According to the DOE, you should determine the type of windows that will work best for your home’s energy efficiency by looking at energy performance ratings. It is also best to look for products that have glazing to help reduce solar heat gain.

• Types. There are different window types by operation, and some of them have lower air leakage rates than others. Fixed windows, for instance, have less air leakage than operable types.

• Installation. As mentioned in the Energy.gov article Energy Efficient Windows, “even the most energy efficient window must be properly installed to ensure energy efficiency. Therefore, it’s best to have a professional install your windows.”

Part II: The Language of Energy Efficient Windows

In the previous post, we discussed about the benefits of energy efficient windows and the basic considerations for shopping according to industry authorities. Now, it’s time to get a better understanding of the things that make window products as efficient as they are, as well as the terms and values that must be looked at.

The Composition

Windows are basically made of parts that can be developed with quality and advanced various technologies to become resistant to heat and cold, making them high-performance home investments.

Glass

To ensure that you get an efficient window, look for products that have low-emissivity (Low-E) glass. This type of glass is designed to let in visible light and harmless heat. Multiple panes with gas filling are also recommended. Furthermore, the spacers between the glass panes must also be high quality and equally efficient.

Framing

There are a variety of quality, durable, and low-maintenance framing materials available on the market today that can enhance insulation and reduce heat transfer. Among them are the following:

• uPVC or vinyl. Known for their affordability, they are said to be poor conductors of heat and their hollow cavities can be filled with insulation. However, as they are cheaper, they might not add value to your home as much as other materials can. They also tend to warp when exposed to extreme temperatures.

• Wood. When we talk about beauty, wood is still number one. It can increase a home’s value significantly and it is an excellent insulator. However, wood windows are expensive and require extensive regular maintenance.

• Aluminum or steel. In their natural state, they are not very efficient as they are both very poor insulating materials. But add thermal breaks and they can be energy efficient.

• Composite. Windows with composite frames are generally weatherproof and need less maintenance. They can almost be equal with wood when it comes to insulation, with added resistance against moisture and rot.

• Fibrex. A relatively new material introduced by Andersen Windows, Fibrex is a revolutionary composite that combines the strength and stability of wood with the low-maintenance features of vinyl. It is also an excellent insulator, at par with wood.

The Values

To ensure that you are getting energy efficient products, you must check the labels and look for ENERGY STAR® and examine the NFRC ratings.

• U-Factor. The rate of heat loss that the window allows; the lower the number, the better.

• Solar Heat Gain Coefficient (SHGC). The rate of incident solar radiation that can go through the product; the lower the number, the better.

• Visible Transmittance. The rate of visible and harmless light that the window can let in; the higher the number, the better.

• Air Leakage. The rate of air that might leak through the window; the lower the number, the better.

Part III: Tips to Keep Your Windows Energy Efficient

In Part II, we discussed the properties of energy efficient windows and the values that must be considered. However, you should know that their ability to reduce your energy costs relies heavily on the way they are operated and maintained. The Energy Performance Ratings that the manufacturers advertise on the labels can actually be affected in several ways. It’s imperative to ensure that your windows are maintained properly so that they live up to those ratings.

Prevent air leakage

Among the biggest factors that affect the energy efficiency of windows are air leaks. A window may be closed, but that doesn’t necessarily mean that air isn’t leaking through small spaces between the frame and the wall.

The best way to prevent air leaks is to apply caulk or install weatherstripping. You’ll need to inspect the sides and joints of the windows for any cracks or holes that may allow air to leak out. It could also be possible that old caulk may no longer be as effective as it used to be. It’s best to remove old caulk or paint (if the window can be re-painted) and apply a new layer to ensure the effectiveness of the product.

Most energy efficient windows will have weatherstripping installed between the fixed and movable areas of the window. Make sure that this weatherstripping remains in optimal condition to prevent air leaks. If you believe that it is already damaged, have it replaced as soon as possible.

Check for cracks

Most energy efficient windows in the market today have two or more panels. The space between the panels is filled with gas or air. If the glass is damaged, it can cause a gas leak, which can reduce the energy-efficiency of the windows. It’s best to check the integrity of the glass on a periodic basis and after a severe weather disturbance.