ABSTRACT
In many commercial building, envelope losses are minor compared to energy use by activities inside the building. Annual heating energy use, for buildings whose heating use is dominated by envelope losses, can be estimated using the building load coefficient method with reasonable accuracy. Solar heating energy let through of glass elements is important for estimating heat gain through glass, beneficial or air conditioning load. Low emissivity coatings are made from thin layers of metal deposited on one or more surfaces of glass. Silk screen shaded glass is made with dot patterns provide shading. Automobile windshields, near the edges, are a ready example of this technology. Modern adhesive window coatings or solar film coatings can repel much of the solar heat gain that otherwise comes through the glass and heats the interior contents. Potential air flow leaving the building is only sustainable if the interior space can maintain the indoor temperature.
