U factor is the rate at which a window door or skylight conducts non solar heat flow.
U factor and shgc standard french doors.
Solar heat gain and u factor.
Solar heat gain coefficient shgc a measure of how well a glazed door assembly absorbs or reflects heat from the sun.
Solar heat gain coefficient measures how well a product can resist unwanted direct or indirect solar radiation.
Doors are a little different.
Energy performance data for select combinations of options is available in table format on each product page.
The u factor of skylights in climate zones 4 to 8 is not to exceed 0 75.
U factor shgc solar heat gain coefficient product type any awning casement double hung fixed casement french door horizontal slider picture window side lite transom single hung sliding glass door storefront door storefront window.
In the south central zone skylights must have a u factor of 0 53 or less and an shgc of 0 28 or less.
In the southern zone skylights must have a u factor of 0 60 or less and an shgc of 0 28 or less.
Doors must now have a much lower u value also known as u factor see below and solar heat gain coefficient before they can earn the energy star label.
The circled value shows you the rating a door has received.
This radiation can cause your home to heat regardless of outside temperature which.
South facing glazed doors in cold climates should have a high shgc.
The milgard energy calculator provides a quick and easy way to help you select windows and doors that can meet local energy codes and project requirements.
Nfrc u factor ratings however represent the entire window performance including frame and spacer material.
In southern climate zones 1 to 3 southern tennessee to the tip of florida there is no u factor cap but the shgc is not to exceed 0 50.
The u factor requirements discussed above for vertical fenestration also apply to exterior glass doors.
This tool gives you the flexibility to select the required energy star zone u factor shgc or vt and determine which milgard window and door products meet the selected requirements.
The lower the coefficient the better the glazed door is at blocking the sun s heat.
It s usually expressed in units of btu hr ft2 of.
Each rating is split into two values.
To access those tables select the individual product of interest and scroll down to the professional resources section.
Glazed doors in hot or temperate climates should have a low shgc.
This tool provides some of the most common options on windows and doors and related nfrc certified values.