To use Solar Control Glass or Not to use Solar Control Glass, is that a question?!

Answer: Yes, it is! It’s a very good question.

Solar control glass, or solar control glazing, is a type of glass that is designed to minimize the amount of solar heat gain and glare that enters a building, while still allowing for the passage of natural light. It is commonly used in skylights, windows and facades of buildings to improve energy efficiency and create a more comfortable indoor environment.

Solar control glass typically has special coatings or tints that help to reflect or absorb a significant portion of the solar radiation, including infrared (heat) and ultraviolet (UV) rays, while still allowing visible light to pass through. These coatings or tints are designed to reduce the amount of heat that is transmitted through the glass, thereby reducing the need for air conditioning and lowering energy consumption.

By controlling the amount of solar heat gain, solar control glass helps to keep the interior of a building cooler, reducing the reliance on artificial cooling systems and improving comfort for occupants. It also helps to protect furnishings, carpets, and other interior elements from fading or damage caused by UV rays.

By utilizing Glazing Vision’s wide range of Solar Control options, we can avoid creating an uncomfortable “greenhouse” space below the skylight within your home.

To start with, let’s go right back to the beginning in terms of glass. If you imagine your windows at home, ask yourself, have you ever had them replaced? When the window is removed you instantly gain more daylight and a clearer view. So, even if the glass is completely clear you will get some solar/ light transmission diffusion. Everything that is then applied to the glass will have an impact on either of these characteristics and it is often a balance between light transmission and heat gain.

The first consideration is applying a Low E coating. Typically, the glass in our skylights always have a Low E coating applied which can be added at various stages of manufacturing the glass.

Soft coat and hard coat Low E

A hard coat Low E is applied during the glass making process when the glass is molten. A soft coat Low E which is supplied by Glazing Vision is applied after the glass is manufactured and it is considered to be more effective at preventing heat loss.

Using a Low E coating will help retain heat in the building during the winter months when you want to keep the heat in a home.

When to apply a Solar Control Coating

Whether you should apply a solar control is very project specific. Firstly, we must look at what the skylight is going to be used for and the room below. Is there a lot of glass on the project? Is the objective to get as much light into the area as possible and what ventilation exists in the area? Is the skylight operable? It can also be client specific; do they want to use a cooled coating to create a certain look?

“The glass industry has developed so much in the 19 years I have been in the industry and you can literally choose from hundreds of different options for solar control finishes, we need to look at the G-value and what heat gain/loss the client is looking to achieve and what their local climate is like so that we can suggest the most appropriate glass to be used” Jon Shooter (Managing Director).

The most common solar control option is a clear coating and becomes a trade-off between heat gain/loss and light transmittance, especially when color is introduced as your light transmittance is going to be impacted.

“Even the orientation is a big factor if the building is south or north facing then that will determine how much sunlight can come into a room and whether heat gain could be an issue” Jeremy Dunn (Technical Director)

Lets take a look at some examples:

Glazing Vision’s standard glass specification – adding solar control glass (SKN154 & SKN175) and just using a blue tinted glass:

Glass Comparisons

Solar control glass

Above you can see how adding the Low E coating in the first glass specification really effects the energy transmittance. Then, increasing the level of SKN solar control coating effects the light transmittance. By just having a tinted glass you reduce the light transmittance, but you don’t gain much else!

With building codes constantly being updated to cater for the ever-changing climate, we are seeing a much higher demand for lower SHGC (Solar Heat Gain Coefficient) values which differ from state to state. For example the solar coating we recommend for New York wouldn’t meet code in California or Texas.

By utilizing our wide range of options, we are able to alter the solar control coating to ensure that the correct coating is applied to meet code requirements no matter where you are.

Most glass manufacturers supply software you can download to find the most appropriate glass and coatings for your project, for example, Saint-Gobain use calumen.com

So, by specifying the correct solar coating we can avoid the requirement for ugly internal shades underneath the skylight and more importantly save on the expense of an additional air conditioning unit in the room. What’s not to like?

Get in touch to learn more about Solar Control Glass or to discuss your glass skylight project.