U Factor For Glass Doors

Nfrc u factor ratings however represent the entire window performance including frame and spacer material.

U factor for glass doors.

The lower the u factor the more energy efficient the window door or skylight. 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. 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. The lower the u value the less heat is lost and the more insulating properties the window offers.

U factor of 0 28 if the shgc is greater than or equal to 0 32. 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. Where can i go for more information. That means the gases effectively block the air exchange between outside and inside.

Solar heat gain coefficient shgc. The range is from 0 to 1. 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. With the equivalent energy performance criteria products can be considered certified with the following performance.

Gases are heavier than air and therefore provide insulation resistance to air. The u value is directly opposite the numbers of an r value. Look for a low shgc in a climate that mainly requires cooling and a high shgc in a climate that requires heating. Or u factor of 0 29 if the shgc is greater than or equal to 0 37.

Note that energy star considers glass doors to be a type of window. The label shows the solar heat gain coefficient shgc and u factor for the door. A u value also known as u factor measures how much heat or cold passes through the window or the door. Or u factor of 0 30 if the shgc is greater than or equal to 0 42.

A low u factor equates to a high r value and both mean the window offers good insulating properties. For most energy efficient windows the whole window u factor is higher than the center of glass u factor. It basically tells you how well a door or window insulates the home. The u factor for dual pane glass products ranges from 0 49 to 0 51.

Low u factors are most important in heating dominated climates although they are also beneficial in cooling dominated climates.