Things have come a long way since the idea of glazed, insulated, energy-efficient windows first appeared in the 1860s. Although energy-efficient windows wouldn’t catch on fully until the energy crisis of the 1970s, we have seen a renaissance of sustainable-building practices and materials in the 21st century.
Despite the prevalence of energy-efficient windows, many homeowners are still reluctant to redo their panes because they think it will be an elaborate and expensive process. This doesn’t have to be the case; and while redoing your home in energy-efficient windows and building materials does require an initial investment, it can actually save money in the long run. Replacing single-paned windows can save as much as $465 a year, according to Energy Star’s statistics. And that’s not even factoring in the environmental benefits.
Karlyn Knafo is the marketing coordinator for Fibertec, North America’s leading manufacturer of energy-efficient windows and doors. We talked with Karlyn to find out more about preserving resources with energy-efficient windows and building materials.
Energy-efficient windows are rated using the NFRC Label. Can you talk a bit about the NFRC label and some of the factors that it measures?
The NFRC label is a stamp of certification from the National Fenestration Rating Council that the windows and/or doors manufactured are energy-efficient and high-performing. The NFRC label can be found on Energy Star-certified windows and doors, and provides the five most crucial ratings that must be taken into consideration when choosing the most energy-efficient fiberglass window for your home. The NFRC label can help you determine how well your fiberglass windows will perform during extreme climate changes such as heat, extreme cold, and heavy winds as well as resistance to condensation.
Can you give a brief overview of energy ratings and what they mean?
Energy ratings are specific measurement units that help us understand how energy-efficient a product is and how much energy we will potentially be saving. Here are some of the more important terms:
U-Factor – The U-factor measures the rate of heat transfer and tells you how well your fiberglass window or door insulates. The lower the U-factor, the better the window insulates.
Solar Heat Gain Coefficient (SHGC) – SHGC can tell you how well your fiberglass windows can block out heat that comes from the sunlight. The lower the value of the SHGC, the less solar heat the window transmits. SHGC can be influenced by the type of glazing used, number of glass panes, and types of coatings that may be used (such as hard or soft coatings).
Visible Transmittance (VT) – Visible transmittance is a value used to measure the amount of light the window lets through. VT is measured on a scale of 0 to 1. The higher the value of the VT, the more light enters through your windows.
Air Leakage (AL) – The air leakage factor is the rate at which air passes through joints in the window. The air leakage value is measured in cubic feet of air that passes through one square foot of window area per minute. If the AL value is low, you will experience less air leakage with your windows.
Limiting the amount of east/west-facing windows is a simple way to reduce solar heating of a home. What are some other ways to easily and naturally heat or cool a home?
East and west facing windows may reduce solar heating in a home, but can also be a source of heating for a home. In Canada, for example, we want to take advantage of all the heating and natural light possible, rather than jacking up the HVAC systems – which not only make the air quality much drier in a home, but will also increase energy costs.
If somebody’s building a new home or just redoing their windows, what are a few general best practices for optimal energy efficiency?
Optimal energy efficiency can be achieved in several ways; it all depends on one’s budget and how much effort they are willing to put into the renovation or new construction. Several well-known methods for achieving energy efficiency are by building according to Passivhaus (Passive House) standards, LEED qualification, or Net Zero Energy construction; or by using high performance building material with no use of spray foam to allow for high air quality in a home. All of these methods will require an airtight seal around the perimeter, which includes (but does not limit the use of) insulation construction panels and high-performance fiberglass windows.
Fibertec uses all fiberglass components instead of PVC. What is the difference and what are the benefits of using all fiberglass?
There are many benefits to using fiberglass over PVC. Our main concern is the quality of our products as well as the health of our customers. PVC omits toxic fumes that are odorless, transparent and colorless which can be very hazardous to one’s health. The great thing about fiberglass is that its expansion and contraction rate move almost in harmony with glass due to their similar properties, allowing fiberglass windows to perform better year-round.
Imagine a vinyl frame that contracts at a completely different rate than glass. There will be a lot of drafty areas, less air tightness, and more condensation. As a result, we choose to use all fiberglass components in order to have a window that has all components move in relative uniformity.
Another easy way to save energy around the home is by making sure windows and doors are insulated. How can a homeowner make sure their home is properly insulated? What impact will correct insulation have over time?
The first step is to determine what the material of your window frame is. Different frames offer different levels of energy efficiency. Next, would be to assure that your windows were installed correctly in terms of leveling and sealing. Lastly, the easiest way to make corrections in the insulation of your windows would be to go over the silicon seal and make sure that there are no leakages occurring from around the perimeter.