Specifying solar control glazing to improve energy efficiency

Specifying solar control glazing to improve energy efficiency

Featured Article
06 Feb 2019

As Featured in GGP Magazine - 06/18

Increased awareness around energy consumption and tightened regulations have resulted in an uplift in demand for solar control glazing. Phil Brown, European regulatory marketing manager at Pilkington United Kingdom Limited, offers a guide to the technology. 

Recent research from the International Energy Agency (IEA) forecasts that air conditioning (AC) units will be one of the top drivers of global electricity demand by 2050, with the number in use growing from 1.6bn today to 5.6bn in that time. 

This tripling in demand is equivalent to the current total electricity capacity of the US, EU and Japan combined. Understandably, this has led to calls for policy action and other measures to improve cooling efficiency and reduce the need for increased power generation. 

One potential solution to help regulate a building’s temperature and prevent overheating is solar control glazing, which can reduce the need for air-conditioning units.

An earlier study commissioned by Glass For Europe concluded that between 15 and 80 million tonnes of CO2 emissions annually could be saved in the EU by the year 2020 by optimal use of solar control glass.

A solar solution

Solar control glazing, as its name suggests, helps to minimise temperature build-up in buildings due to sunlight. 

When specifying solar control glazing, the most important parameter to consider is the total solar heat transmittance or g value. It includes the proportion of solar radiation transmitted directly through the glass, and the proportion of solar radiation absorbed by the glass and re-radiated into the building. Generally, the lower the g value, the lower the solar gain through the glass.

Installing solar control glazing can help lessen reliance on air-conditioning systems as well as reducing a building’s carbon emissions, making it more appealing to a growing number of energy- and money-conscious consumers. 

A case in point

Solar control glazing can also be combined with other glass products to bring additional benefits. One recent example of this in action was on Pilkington’s work on the newly completed 122 Waterloo Street office building in Glasgow. 

An issue that can affect buildings where most of the envelope is glazed is excessive heat build-up when the sun is shining directly into the interior. This can present a challenge for building managers and often requires high levels of energy-intensive air conditioning to keep occupants cool.

To combat this, a solar control coating was used on the glazing, reducing the amount of heat energy able to enter the building while maintaining high levels of transparency.

The Pilkington Suncool™ 70/35 T coating selected by the project design team offers high visible light transmittance, reduced solar transmittance and excellent low-emissivity all in one product.

This means the floor space will be brightly lit by sunlight but won’t suffer from overheating on warmer days.

Additionally, the scale of the building and the large area of glass used means that excessive radiation of heat from the building could lead to rapid heat loss during colder conditions, requiring an increase in heating to keep the interior warm.

To mitigate this effect, the glazing features a Pilkington Optitherm™ S1 Plus low-emissivity coating which reflects radiated heat back into the building.

The scheme has been certified BREEAM Excellent and achieved an ‘A’ rated Energy Performance Certificate (EPC), the latter based on a detailed assessment of the building’s energy performance. 

Looking ahead

Modern solar control glass systems will continue to be in high demand over the coming years, and we’re committed to innovating and bringing new products to the market. The end result is a built environment that is more energy-efficient and less reliant on air-conditioning units, boosting environmental benefits and financial savings in the long run.