Ask The Expert Answer Archive
The terms "Design Pressure", "DP," "Performance Grade," "PG," and "Structural Test Pressure," "STP" have in the past been loosely used by some in the field. This answer will clarify what the differences are between them.
The biggest difference between U-factor and R-value is that U-factor measures the rate of heat transfer (or loss) while R-value measures the resistance to heat loss. R-value is a measure of conductivity.
There are several terms that homeowners can familiarize themselves with so they can better understand the science behind energy efficient windows. They are conduction, radiation, convection, air infiltration, and radiant heat loss.
My city requested that I have tempered glass windows. Is this code for southern California? Or does this meet the safety glass minimal standard?
Local jurisdiction always is the last word for tempered requirements for safety glass.
Standards in the door and window industry are constantly evolving due to changes in technology, building codes and rating system performance requirements. This has led to some confusion around the differences between Design Pressure, Performance Grade, and Performance Class.
The MI EnergyCore double hung window was designed from the ground up using state of the art computer aided design software, finite element analysis, and thermal analysis. Design considerations like water exfiltration were planned and accounted for to make this one of the soundest window systems available on the market today.
Your EnergyCore brochure refers to TMAX glass. Do you have information on visual transmittance information on TMAX?
At MI Windows and Doors we offer a variety of glass types to meet different requirements. Considerations includes climate, sound control, UV protection, and enhanced security. We offer many different glass types, but here are our main three offferings:
In one or two family dwellings, Section R310.1 of the International Residential Code requires basements, habitable attics and every sleeping room shall have at least one operable emergency escape and rescue opening. All emergency escape/rescue openings shall have a minimum net clear opening of 5.7 square feet, except grade floor openings shall have a minimum net clear opening of 5 square feet.
Condensation on your windows can be controlled by making sure that the moisture in your home is balanced out by using ventilation. Getting this balance right can be tricky, depending on your type of heating, levels of insulation in your home, and the amount of ventilation you already have.