Windows, The Other Part of a Wall
By Jody Howe
CEC Sr. Energy Specialist
Did you know windows can make a significant impact in your home? It becomes clear you may be losing control of your heating or cooling when you stand near your windows and feel more drafts, the heat of the sun, and the chill of winters. Your home may even see more dust from today’s dryer environment. If the outside noise is obvious to you, the improvement when upgrading windows will also add quiet to the energy savings.
There are multiple parts to a window and each contribute to efficiency:
Frames – designed with more insulation and thermal break.
Panes of glass (2 or 3) – improve unwanted solar heat flow from entering the home.
Spacers – separate panes reduce heat flow; prevent intrusion of condensation and noise.
Coatings- create low emissivity (“low-E”) glass to reflect heat either into or out of the house.
Together each parts performance quantifies an Energy Performance Rating as seen in this sticker example below: window U-factor, Solar Heat Gain Coefficient, Air Leakage and Visible Transmittance.
The National Fenestration Rating Council (NFRC) is a 3rd party certifier. Fenestration refers to all things related to windows and doors. Its origin is Latin “fenestra” meaning “opening”.
CEC’s program requires a U-factor of 0.30, we recommend upgrading to Oregon’s new building code (April 2021) requirement of 0.27 U-factor. Yes, lower is better.
CEC offers $5.00 per sq/ft incentive until October 1, 2021 for window replacement. Your existing windows must qualify under the program requirements: single pane wood frame or any metal frame. Pre-1980 homes are more commonly recipients to receive incentives.
Window orientation: exposure to sun, shading or not in a particular location also plays a role in choosing type that reduces energy use.
Window installation is essential to performance. Remember this “other part” of a wall; windows fill the holes in your walls that separate you from the outdoors. Seek out trained installers get some bids. If you are a DIY installer, make sure to follow manufactures instructions. Learn about lead dust in homes built earlier than 1978. If your window frames show signs of damage due to weather understand how to mitigate and resolve before new install. Review the importance of proper flashing tape or ridged cap.
New windows payback in the thermal comfort, reduced energy use and potential savings, which vary home to home. Visit CEC’s website and view the “Weatherization” program for more details. https://www.cec.coop/customer-service/energy-efficiency/residential-programs/weatherization-program/ or contact one of our Energy Specialists at 541-548-2144.