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Low-E Glass FAQs

1. Can you use PPG Low-E glass in a single-glazed window?
2. Is it better to have the coating on the #2 or #3 surface of an insulating glass unit?
3. What are the differences between PPG Low-E coated glass products?
4. Do all Low-E coated glasses look the same?
5. How much does PPG Low-E glass reduce the transmission of ultraviolet (UV) energy?
6. Can tinted glass be used with Low-E glass?
7. How effective is tinted glass with PPG Low-E coatings?

7 Total Questions

1. Can you use PPG Low-E glass in a single-glazed window?

Sungate® 500 coated glass can be used single-glazed, provided that the coating is oriented toward the interior of the building. However, PPG does not recommend that the product be used in single glazing applications due to the increased difficulty in routine cleaning. The crystalline nature of the coating can cause dirt and other contaminants to become more difficult to remove, and normal cleaning solutions can leave streaks due to the increased difficulty in removing them before they evaporate.

Sungate® 400 and Sungate® 600 coated glasses and Solarban® 60, Solarban® 67, Solarban® 70XL, Solarban® 72, Solarban® Z50, and Solarban® R100 coated glasses must be used only as a component of a sealed insulating glass unit.

In addition, all Low-E coated glasses yield their best energy performing characteristics when used in a sealed insulating glass units.

2. Is it better to have the coating on the #2 or #3 surface of an insulating glass unit?

The answer to this question is really dependent on the specific design conditions of your application. The light transmittance and the U-value of the unit will be the same whether the coating is on the #2 or #3 surface; however, the Solar Heat Gain Coefficient will be lower when the coating is on the #2 surface.

In general, if you are concerned about reducing solar heat gain (typically in a cooling climate), then using the coating on the #2 surface would best meet the requirement. On the other hand, if you are interested in utilizing passive solar heat gain (typically in a heating climate), then using the coating on the #3 surface would best meet the requirement.

3. What are the differences between PPG Low-E coated glass products?

PPG manufactures a variety of low-e coated glasses using two different manufacturing processes. The following table identifies the PPG product and associated manufacturing process.

PPG Low-E Coated Glass Products
Product Manufacturing Process
SUNGATE 500 Coated Glass Pyrolytic
SUNGATE 600 Coated Glass Pyrolytic
SUNGATE 400 Coated Glass MSVD
SOLARBAN Z50 Coated Glass MSVD
SOLARBAN 60 Coated Glass MSVD
SOLARBAN 67 Coated Glass MSVD
SOLARBAN 70XL Coated Glass MSVD
SOLARBAN 72 Coated Glass MSVD
SOLARBAN R100 Coated Glass MSVD

In the Pyrolytic manufacturing process, the coating is applied to the glass ribbon while it is being produced on the float line and the coating then “fuses” to the hot glass surface. The glass is then cut into stock sheets of various sizes for shipment to fabricators. For pyrolytic coatings, Sungate® 500 and 600 coatings are very durable, both mechanically and chemically. And, while Sungate 500 and 600 coated glasses offers reduced emissivity and some solar control, they do not perform quite as good as PPG’s MSVD.

In the MSVD (Magnetic Sputtering Vapor Deposition) process, the coating is applied to pre-cut glass (usually in stock sheets for further fabrication) in a vacuum chamber at ambient plant temperatures. MSVD coatings such as Sungate® 400 and Solarban® 60 Low-E glasses offer lower emissivity and superior solar control versus pyrolytic. However, MSVD coatings are not as durable as pyrolytic coatings, either mechanically or chemically, and must always be used as a component of an insulating glass unit with the coating located within the sealed airspace.

4. Do all Low-E coated glasses look the same?

No, they do not. Color differences between various low-e coatings are due to the use of different coating materials, the thickness of the various coating layers, as well as differences in manufacturing processes.

5. How much does PPG Low-E glass reduce the transmission of ultraviolet (UV) energy?

The reduction in the transmittance of UV energy is dependent on the specific PPG low-e coating and the make-up of the insulating glass unit, i.e., glass thickness, glass type, etc. Please refer to the product performance charts for specific information.

6. Can tinted glass be used with Low-E glass?

Yes it can. Tinted glass can be used as the outdoor lite in an insulating glass unit, with PPG Low-E as the indoor lite. The low-e coated glass improves the insulating properties of the insulating glass unit, while the tinted glass reduces the influx of solar energy through the insulating unit.

7. How effective is tinted glass with PPG Low-E coatings?

  • Tinted glass is very effective when used in conjunction with PPG Low-E glass. This combination will reduce excess heat gain and lower cooling costs.
  • The tinted glass reduces the amount of excess heat gained on east, west, and south exposures
  • Tinted glass can provide improved glare control, if needed.