This type must be used exclusively in insulating glass. This allows the sun’s heat and light to pass through the glass into the building. At the same time it blocks heat from leaving the room, reducing heat loss considerably.
Low-emission glass (Low-E) is a clear float glass; it has a microscopically-thin coating of metal oxide with magnetically-enhanced cathodic sputtering. The coating used to make low-E glass works to transmit short wave energy, allowing light in, while reflecting long wave energy to keep heat in the desired location.
Low-E glass is glazed with an ultra-thin metallic coating.
In especially cold climates, heat is preserved and reflected back into a house to keep it warm. In especially hot climates, low solar gain panels work to reject excess heat by reflecting it back outside the space. Generally low-E windows cost between 10% and 15% more than standard. The reduction in energy loss can be 30% to 50%. Low-E windows are a larger investment initially but will pay for themselves by reducing heating and cooling costs.
Glass 4+16+4 filled with air has U-value W (m2K) =1,4, while filled with gas 1,1.
Ponistra d.o.o. produces low-e glass and incorporates it in every product.