Notice: These values are for the middle of glass only. They ought to only be used to check the effect of various glazing varieties, not to check overall window goods. Frame alternative can considerably have an impact on effectiveness. These values signify double glazing by using a one/two″ air gap. https://how-much-to-install-secon05948.blogozz.com/33829697/the-5-second-trick-for-secondary-glazing-windows