Green Windows Barre VT
East Montpelier, VT
Randolph Center, VT
East Montpelier, VT
Green Building Windows & Doors
Green Windows & Doors Resource
From a green-built standpoint, windows rank second only to the design of an HVAC system in overall technological complexity. Heating, cooling and lighting consume 67% of all the electricity that’s generated. Windows and doors comprise a large portion of heat loss in a wall and lower the overall R-Value of the wall. Installing windows and doors correctly will help eliminate air infiltration and water leaks.
See Chapter 7 on Windows & Doors in the Green from the Ground Up book for more details or contact us about training .Window Energy Performance
There are three primary factors in a window's energy performance:frame construction glass spacer material that separates individual panes of glass through the glass (by radiation) across the spacer material that separates the two glass layers at their edges and through the frame of the window (by conduction) through the movement of air in the space between the glass (by convection) between the moveable or operable frame components (by air leakage) Rating Windows for Performance
The National Fenestration Rating Council (NFRC) was formed to standardize the claim of energy efficiency by window manufacturers.
U-factor - for the entire window, distinct from a center-of-glass rating.
Solar heat gain coefficient - represents the amount of heat that is transmitted through the glass. The lower the number, the less heat transmittance.
Visible light transmittance - is the "sunglasses" effect. The lower the number, the darker things will appear through the glass.
Air leakage - is rated in cubic feet of air passing through a square foot of window area. The lower the number, the less air will pass through cracks in the assembly. This may be left blank by manufacturers of lower-quality windows.
Condensation resistance - measures the ability of the window to resist condensation on the inside of the glass. The higher the number the better.Green Window & Door installers’ Transition Guide
Familiarize yourself with which windows are available in your area
Learn about what technologies are available to market to your customers
Many manufactures and dealers offer training and free seminars
Consider wood windows
High quality and long life
Available in replacement sizes and installation
More expensive than vinyl, Use FSC wood or engineered materials
Carefully install windows and door to eliminate any air leaks
Even a small air leak can have a huge impact on heat loss over the life of the building
Use expanded foam around all windows and doors. Be sure that head flashing is installed
One can of expansion foam. Look for products that use HFC rather than HCFC or CFC as propellants.
Understand the prevailing winds on the site
Wind will push on a building and contribute to air infiltration. Understanding the prevailing winds can also help you to take advantage of cooling breezes