Low-E (low emissivity) coatings are applied to glass to reduce the amount of heat that is transferred through the glass. There are two types of Low-E coatings: soft-coated and hard-coated.
Soft-coated Low-E is a thin layer of silver or other metal that is applied to the glass using a vacuum deposition process. This type of coating is very effective at reducing heat transfer and is often used in high-performance windows. Soft-coated Low-E is also more durable than hard-coated Low-E and is less likely to degrade over time.
Hard-coated Low-E is a layer of tin oxide that is applied to the glass using a pyrolytic process. This type of coating is less effective at reducing heat transfer than soft-coated Low-E, but it is more affordable and easier to manufacture. Hard-coated Low-E is also more scratch-resistant than soft-coated Low-E, which makes it a good choice for applications where the glass may be exposed to abrasion or wear.
