When Deniziak Siding and Windows, factory-trained crew installs the windows in your home, you'll bring the beauty and sunlight of the outdoors indoors. You'll receive energy-efficient, secure, dependable and stylish windows from quality manufacturers! Windows are available with Heat Mirror a unique patented window insulation system. It consists of a specially coated polyester film which is suspended between two panes of glass. It is transparent to light but is highly heat reflective. This results in a finished product which looks clear, just like ordinary glass, but has dramatically improved insulation performance.