The Role of Solar Control Window Films in Sustainable Architecture
Sustainable Architecture: A Future Design
Sustainable architecture is used to calibrate the design strategy and create a building that supports environmental norms. Architects consider several factors in designing the building, such as prioritizing recycled and recyclable materials, minimizing demolition, construction, unnecessary material consumption, choosing locally sourced materials, etc. It leads to smart designs and the use of available technologies to maximize energy management and rainwater management.
Architects make use of several sustainable architecture strategies for their sustainable designs. One such strategy is taking the sun orientation and climate of the place while designing the structure. This gives the daylighting and natural ventilation and saves the energy requirements. The orientation of the building according to the sun gives natural sunlight during the daytime. Similarly, native landscaping can greatly help with light and aesthetic needs. The use of native trees, plants, mounds, etc., can reduce the construction cost as well.
Further, the use of green building materials reduces environmental costs and provides environmentally responsible manufacturing techniques. The architects are significantly dependent on mechanical and electrical engineers for solutions on implementing HVAC, electrical, plumbing, and other systems that are independent of the environmental consequences. Similarly, using rainwater harvesting strategies, such as permeable pavement, could conserve water management locally.
Moreover, the windows can be used to maximize the input of heat-creating light while minimizing the loss of heat through the glass. Windows can be designed to maximize natural light. Double-glazed windows, solar control window films, and Low-E glass can be used to reduce energy consumption. Sustainable architecture building is the future of construction. It involves a building that minimizes environmental impact, uses renewable energy sources, and minimizes waste generation.
Prominent Examples Of Sustainable Architecture
Sustainable architecture, such as green buildings, typically uses less energy and less water than other buildings. This aligns with the circular economy principles. There are several green buildings designed worldwide, setting an example for development.
One such building is the Bullitt Center is located in Seattle, Washington. It is a six-story, 50,000-square-foot office building. The building generates 230,000 kilowatt hours per year, with 575 solar panels on the roof. Further, almost all the water used in the Bullitt Center comes from captured rainwater. 56,000 gallons of water is stored in the concrete cistern in the basement, which is brought from the parapet roof that downspouts the water. The day-use tank that holds 500 gallons of potable water next to the cistern.
The building has triple-pane glazing and deployable exterior shades to help maintain interior temps. The outermost layer of the building is the deployable stainless steel shades, which are about 12 inches away from the windows. In the winter, the shades maximize natural daylight, and in the summer, the shades deploy to scatter direct rays from the sun. Each window unit weighs 532 pounds.
Moreover, the Shanghai Tower is located in Shanghai, China. It is 2,073 ft high and 128 stories high. This is the world’s third tallest building. The building is divided into nine tiers vertically, enclosed by the inner layer of the glass façade, which completes a 120-degree twist as it rises. The building has two transparent layers of glass façade. The double layer of glass eliminates the need for either layer to be opaque and reduces the indoor air conditioning and heating. 20,589 wall panels with 7,000 unique shapes are used, and they are suspended from above on massive cantilevered trusses. This complicated structure uses a control window and glasses to save maximum energy and give differentiated looks.
Solar Control Window Films Application
Solar-control films are used to reject the excessive sunlight during summers and absorb the minimum heat during the winters. These films can provide significant savings. They can be installed on the interior or exterior side of the window and reduce the amount of solar energy. The solar control window films reduce heat gain, block UV radiation, and moderate the amount of visible glare entering the room. These films reduce the air conditioning cooling load during summer and winter, preventing heat loss.
The major benefit of using solar control window film is that it provides cost-effective solutions for big buildings. Big buildings generate CO2 emissions, so solar-controlled window film can add more insulating power to glass and reduce CO2 emissions.
One such beneficial product is Suntrol window film, which can be installed quickly at about one-fifth the cost of replacement windows. It offers 3 times more energy savings and pays for itself within 5 years of installation. It can be beneficial for saving 50% on summer cooling costs, 33% on winter heating costs, and a limited lifetime warranty. The product also provides bird-deterrent technology.
Table 1.1: Solar Control Window Films, Products
| Product | Descriptions |
| 3M Window Films | 3M Sun Control Window Film Traditional Series offers improvement in energy performance, budget comfort, reduction in the 99% of harmful UV rays, reduced glare and eye discomfort, and heat reduction at a low cost. The product gives a warranty from 3M. It includes silver reflective films, rejecting up to 79% solar. Further, the series also included P18 Classic silver. The darker tint reduces glare and increases reflection for daytime privacy. |
| Solar Gard Window Film, Saint-Gobain | Solar Gard offers window film comfort, energy savings, and aesthetics for different needs and requirements. Such as Panorama CX, Panorama Hilite, PureVue Ceramic, Quantum, Sentinel Plus, Silver, Solar Bronze, Stainless Steel, Sterling, etc. Silver series are constructed by sputtering thin layers of precious metals onto film. This gives a line of reflective films and provides high privacy and heat rejection. Panorama CX is a ceramic product that provides high heat rejection without sacrificing views; the sputtered ceramic technology rejects up to 58% of total solar energy. Quantum films provide a dark aesthetic with low reflectivity, controlling glare and enhancing privacy. |
| Opalux Solar Reflective Window Films | Opalux Solar Reflective Window Films can make up to 80% reduction. The product gives solar heat & glare reduction and daytime privacy. It can hide internal clutter and give a uniform reflective image. This film type is commonly used in solar control films in the UK and worldwide. |
| High Reflective Silver Window Film Solar Control by Window Film | The product can reject 78.0% of the total energy, 79.0% glare reduction, and 99.0% ultraviolet rejection. It significantly reduces high levels of incoming solar heat and glare coming in through the glass. The reflective silver film works give an external mirrored appearance to the glass. It gives one-way daytime privacy for security. Filters out virtually all UV rays, which protect fabrics and furnishings. |
Commercial Benefits Associated With Solar Control Window Films
Solar window films help reduce heat entering the building through windows, maintaining a more comfortable indoor temperature. Less energy is needed for heating or cooling, which saves money. The film blocks UV rays and keeps the room cool without turning on the air conditioning, thus keeping the temperature down naturally in a building and saving energy. The use of air conditioners is commercially heavy for households and businesses.
Particularly during the summertime, the use of solar film in the windows was notably reduced by more occasional use of air-conditioning systems, and thus the electricity bills. Using less electricity is important for reducing the greenhouse gas emissions associated with electricity production.
Solar films block UV rays entering the building and their damaging effect on objects. It prevents the deterioration and fading of furniture, walls, and interiors. Users save money on interior maintenance and can give alternative decorations.
Today, many buildings are subject to environmental standards, giving a competitive disadvantage to buildings with a poor environmental performance index (EPI). By using solar control window films, certification standards such as LEED (Leadership in Energy and Environmental Design) or BREEAM (Building Research Establishment Environmental Assessment Method) can easily be met, and these standards automatically increase their value.
It was estimated by gsa.gov (US Govt.) that 28% of the cooling energy demand is due to the heat gain in windows. They also modeled the energy performance of both spectrally selective absorbing and reflective films in warmer climates. The modeled energy savings for a range of base windows and climates payback for liquid-applied absorbing @ $8/ft2 (80% of the current cost) and reflective @ $10/ft2.
The liquid-applied absorbing film is ineffective in saving energy for heating and cooling. The solar-control films can provide significant cooling savings. It is effective in buildings with single-pane clear windows. In the buildings, these are used against the direct sun without exterior shading and south, east, or west orientations. Reflective film is currently more cost-effective and broadly recommended.
Figure 1: Modeled Energy Savings by Liquid-applied Absorbing and Reflective Absorbing Spectrally, Single Clear, Payback in Years
Source: gsa.gov
Other Key Benefits:
Window film installations are typically much more affordable than other window coverings and can normally pay for itself within a few years. Solar Films provide UV protection, and infrared light reduces the chance of fading office interiors and exteriors. It improves commercial window energy efficiency and increases building tenant comfort and productivity. It could significantly decrease glare and reduce reliance on AC systems. It provides a strong return on investment (ROI) by giving carbon negative in a few months of usage.
The Skin Cancer Foundation suggests that unprotected exposure to UVA and UVB damages the DNA in skin cells, which leads to skin cancer and eye damage. Solar control film protects from harmful UV. Solar control window film can act like a ‘sunscreen for windows,’ which protects skin and eyes from UV damage. Further, reflective solar control window film provides 1-way mirror privacy during the day, thus giving privacy at home or work. These multiple benefits further expand the role of solar control window films in sustainable architecture.
Green Building Certification:
Sustainable building certifications are a known requirement of buildings to maintain certain standards to be differentiated from other buildings. These certifications recognize the commercial, residential, government, etc. Types of buildings with certain green parameters support them in expanding their boundaries.
Certain global certifications are gaining traction for their benefits. Certification elevates the market standards for buildings worldwide, as it sets higher standards than government building codes and regulations. This significantly elevates workforce requirements and business strategies. Certification tools can be used for different building types, such as homes, commercial buildings, or neighborhoods.
One such notable certification standard is LEED (Leadership in Energy and Environmental Design), based in the United States provides certification for healthy, efficient, and cost-saving green buildings. LEED is amongst the largest certification networks around the world. There are more than 111,857 total LEED-certified projects worldwide by February 2024. There are nearly 66,412 certified LEED commercial projects, 45,406 certified LEED residential projects, and more than 250 certified LEED for Neighborhood Development projects. It operates in 186 countries with more than 3,200 individual members and 5,300 organization members.
Figure 2: Leed-certified Projects, Commercial and Residential, by February 2024
Source: USGBC Statistics
LEED guarantees certification for Building Design and Construction (BD+C), Interior Design and Construction (ID+C), Building Operations and Maintenance (O+M), Neighborhood Development (ND), Homes, and Cities. LEED is backed by USGBC (U.S. Green Building Council, Inc.), headquarters in Washington, D.C.
Furthermore, the German Sustainable Building Council (Deutsche Gesellschaft für nachhaltiges Bauen e.V., DGNB), was founded in 2007 having with more than 2,300 member organisations. It is Europe’s largest network for sustainable building. The DGNB has awarded more than 10,000 projects in around 30 countries. DGNB provides certification systems for sustainable buildings and districts. It can give feasible solutions on both a small and large scale, and via the DGNB Academy, it provides training and education platforms for sustainable planning, construction, and real estate management.
Moreover, the Indian Green Building Council (IGBC) is part of the Confederation of Indian Industry (CII) and was formed in 2001. IGBC rating systems are voluntary, consensus-based, market-driven programs. There are 2,218 organizational members, 14,511 registered projects, and a 12.30 billion sq. ft. green building footprint through 62 offices with 8 overseas offices.
The use of these solar control window films in sustainable architecture for commercial buildings can help LEED credits and other potential certifications. Further, window films can have Solar Heat Gain Coefficient (SHGC) and Visible Transmittance (VT) ratings by the National Fenestration Ratings Council (NFRC). The lower a film’s SHGC, the less solar heat it transmits, and the higher the VT rating, the more visible light is transmitted. The various certifications certainly uplift the demand for solar control window films in sustainable architecture.
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