Replacement Window Glass
Your Home Exterior Solutions
Glass that meets the tax credit standards are now in mass production across the country. Manufacturers have had to change their production lines to keep up with the increasing pressures from the consumer and the government to make it better. There is some teeth in the new policies to meet higher standards and the producers of these products are under a watchful eye to test and re-test the components to make them more efficient and structurally better.
This is good news for consumers but it wasn’t scientists who placed the standards on the performance it was the EPA and DOE. The reality is they set one number for the entire country as the standard but it doesn’t take a scientist to realize the heating and cooling degree days are quite different in Florida than they are in Boston.
The current guideline to meet the energy tax credit states BOTH the U- value AND the SHGC (solar heat gain coefficient) must be less than or equal to .30 . So, the lower the U-value the slower heat escapes through glass to the outside, the better it is. The Solar heat gain is how much heat will be allowed through the glass from an outside heat source like the sun. THE catch is these numbers must represent the windows TOTAL OVERALL PERFORMANCE which means the frame and its ability to stop drafts and wind loads is factored in for the testing. This combined with the seal used to hold the two or three panes of glass together and the structural integrity of the frame make the glass a secondary concern to the quality of the frame it is supported by.
It is hopeful that in the future the numbers will be set to reflect the needs of the different climates we live in but for now we will just stay the coarse and do our best to comply. It will be beneficial to a homeowner to discuss customizing the glass in an individual home depending on what side faces north, south etc, as different glass applications can be utilized to get the most out of our best natural resource the sun.
So as we continue to make the wheel better we have come along way and most windows today meet the minimum standards.
You can see these products in your home and get all the facts in person.
