Frequently Asked Questions

1. Manufacturing Process

Hard Coat Low-E (Pyrolytic) Glass: The Low-E coating is applied during the glass manufacturing process while the glass is still hot. This causes the coating to fuse with the surface, creating a durable and scratch-resistant layer.
 

Soft Coat Low-E (Magnetron Sputter Coating - MSVD): The Low-E coating is applied in a vacuum chamber after the glass has cooled. This process allows for multiple layers of coatings, improving performance but making it more delicate.
 

2. Performance Differences

Hard Coat Low-E:

More durable, suitable for single-glazed applications.

Allows more solar heat gain (higher SHGC), making it better for cold climates.

Slightly lower energy efficiency than soft coat.
 

Soft Coat Low-E:

More effective at blocking heat transfer, providing superior insulation.

Has lower emissivity and higher reflectivity, making it better for energy efficiency.

Ideal for double- and triple-glazed IGUs (insulated glass units).
 

3. Visible Differences

Hard Coat Low-E:

Has a slightly hazy or rougher appearance.

Can sometimes appear to have a slight tint or less clarity when compared to uncoated glass.
 

Soft Coat Low-E:

Generally clearer and less noticeable.

Has a slight reflective quality, but not as visible as hard coat’s haze.
 

4. Application Considerations

Hard coat is often used in single-pane applications but can be use in double glazed units.

Soft coat is more common in high-performance double- or triple-glazed units, because it must be sealed inside the IGU for protection.
 

In summary: Soft coat Low-E is more efficient but must be inside an IGU for protection, while hard coat is more durable but has a slight haze and higher solar heat gain. Visibly, soft coat is clearer, whereas hard coat can appear slightly hazy or textured.