U Factor For Glass Doors

A low u factor equates to a high r value and both mean the window offers good insulating properties.

U factor for glass doors.

The lower the u value the less heat is lost and the more insulating properties the window offers. Improved education and awareness of the cost of heating and cooling that escapes from poorly insulated components and glass panes have led to window and door manufacturers developing energy efficient windows and doors typically labeled r5 u 2 meaning the glass is the most energy efficient possible at a 5 rating and the window or door with all of it s built out components are a 2 which is almost as low as any rating can go remember a 5 is the highest energy rating for r value which is. The u factor will approach the very low 0 15 point if there is a gas such as argon or krypton between the layers of glass glazing. The label shows the solar heat gain coefficient shgc and u factor for the door.

The u value is directly opposite the numbers of an r value. Low u factors are most important in heating dominated climates although they are also beneficial in cooling dominated climates. With the equivalent energy performance criteria products can be considered certified with the following performance. It basically tells you how well a door or window insulates the home.

High performance double pane windows can have u factors of 0 30 or lower while some triple pane windows can achieve u factors as low as 0 15. For most energy efficient windows the whole window u factor is higher than the center of glass u factor. That means the gases effectively block the air exchange between outside and inside. Basic dual pane glass is available on most andersen 200 series windows the perma shield patio door and the narroline gliding patio door.

For windows skylights and glass doors a u factor may refer to just the glass or glazing alone. U factor of 0 28 if the shgc is greater than or equal to 0 32. Note that energy star considers glass doors to be a type of window. The lower the u factor the more energy efficient the window door or skylight.

Where can i go for more information. Look for a low shgc in a climate that mainly requires cooling and a high shgc in a climate that requires heating. Solar heat gain coefficient shgc. A rating factor that measures how much heat is lost through a given window.

Or u factor of 0 29 if the shgc is greater than or equal to 0 37. Gases are heavier than air and therefore provide insulation resistance to air. The solar heat gain coefficient tells you how much heat from the sun is able to pass through the glass of the door or window. Nfrc u factor ratings however represent the entire window performance including frame and spacer material.

The u factor for dual pane glass products ranges from 0 49 to 0 51.