The science behind innovative windows & doors

Given the extreme temperatures in India, modern fenestration solutions are needed in ensuring indoor comfort and convenience, says YP Singh, head of product solutions and manufacturing, Fenesta Windows

YP Singh, Fenesta Windows, Doors and windows, Prof NK Bansal, Center of Energy Studies, IIT Delhi

Across India, summers, winters and monsoons can each bring extreme weather conditions. As a result, depending on the season, being indoors can make the heat or cold unbearable. Similarly, monsoons can bring problems such as seepage or water entering indoors via doors and windows. Fortunately, scientific fenestration solutions offer doors and windows addressing these issues in residential, commercial or office premises.

Whether personal or professional, the deciding factor for choosing appropriate doors and windows is the comfort levels offered indoors. Human comfort levels revolve around three indoor parameters: room temperature, Noise insulation and natural light.

Important parameters
In maintaining room temperature, installing the right type of doors with adequate sealing helps in reducing heat loss or gain. Heat insulation is achieved from the frame, panel configuration and the sealing between the two as well as the installation or sealing of the door with an aperture. In technical parlance, it is termed the ‘U-value’. Lower the U-value, better the insulation. Typically, U-value of 2.0 to 2.5 is good.

The second parameter concerns Noise insulation, which is crucial, given the high noise pollution levels today. For proper sound insulation, selecting the right material and configuration backed by proper installation results in good insulation. Technically, these can be compared with Sound Transmission Class (STC) where 30+ value is deemed good. For comparison, a 9” wall can ensure 50+ STC value.

The third parameter deals with the ingress of natural light. Modern doors and windows energise and brighten the room through sufficient natural light. Whatever the requirement, innovative fenestration solutions are effective in improving indoor thermal comfort.

The first level of thermal comfort comes from the building design itself. Therefore, other elements apart, architects and designers ascertain a building has a proper orientation to the sun’s path, wind direction and altitude. Façades having high exposure to excessive heat or cold must be well insulated via the least number of wall openings. It’s no surprise that the best examples of such architecture are seen in heritage buildings as ancient builders remained in harmony with Mother Nature.

The second level of thermal efficiency results from fenestration and depends on design and material selection. Here, fenestration materials and glasses with medium-to-high insulation should be selected. Materials such as wood, uPVC and thermal break aluminium have better U-value. Likewise, glasses should be low E-coated, double or triple glazed to achieve lower U-value. Avoid reflective glasses as these eliminate much of the visible light transmission, especially in the morning and evening, reducing natural light.

Monsoon concerns
Apart from summers and winters, monsoons also bring distinct problems. The main challenges are ensuring effective barriers against extreme monsoons and strong winds and installing a conventional ‘face drainage’ mechanism. Once again, innovative fenestration solutions offer customers value-for-money windows & doors that are well-designed, robust and aesthetically pleasing too.

In coastal regions, monsoon precipitation rates are extremely high. Making matters worse, monsoon storms arrive with high-velocity winds. The combined force of the wind and rain destroys traditional windows. Their force is magnified in high-rise buildings, where rain spears in at a sharp 45° angle, accompanied by storms. Consequently, the face drainage mechanism in conventional uPVC windows cannot handle heavy monsoon zones as the force of the wind drives the rainwater indoors.

But modern fenestration solutions provide three innovations to keep the rain out. The first is the Rain Track – an elevated section clipped on the inside track of the window, functioning as a dam. It captures rainwater and then drains it out. The second is the Sill Arrangement – a special system that prevents air pressure from pushing rainwater indoors. Thanks to this, the rainwater ends up flowing vertically, some distance away from the outer wall. The third is the gradient slope – a track at a downward slope  ensuring accumulated rainwater flows out.

Another major concern in India is strong winds, with wind speeds being much higher than elsewhere in the world. Along the coast in the east and west, wind speeds reach over 200 kmph. This equals wind loads of 2000 Pascal. In such conditions, conventional windows can rattle and whistle. It is worse in high-rise buildings – a mild breeze on the ground floor turns into a gale-force wind in its upper reaches.

In such situations, only scientifically-made airtight windows can cope with extremely strong winds while traditional ones may collapse. These airtight windows have broad sections reinforced with steel and further strengthened with a special Hurricane Bar, which also acts as a handle. Multiple seals stop the ingress of air. Thereby, it eliminates whistling and rattling sounds even at 3000 Pascal wind loads and can withstand wind speed of 245 kmph.

Managing radiation
Finally, in Indian conditions, solar radiation can be far higher than other geographies as the country is situated in one of the world’s highest UV-receiving regions. India also confronts climatic extremes. In summers, temperatures soar as high as 50ºC in the northern Gangetic Plains, Rajasthan and Gujarat. In winters, hill temperatures often fall below freezing.

To withstand such severe conditions, modern fenestration solutions offer a special uPVC blend – a unique tropical formulation withstanding extreme annual radiation. The innovative windows contain titanium dioxide, which imparts colour stability even under intense UV rays, impact modifiers ensuring extra strength to carry huge loads and heat stabilizers to prevent material degradation and boost all-weather stability.

Experts note that energy-efficient windows & doors can save almost 30% energy, says Prof NK Bansal, Center of Energy Studies at the Indian Institute of Technology New Delhi. Leading to lower electricity bills and higher levels of indoor comfort and convenience even while ensuring minimal environmental impact during their manufacture. There cannot be better reasons in opting for modern innovative fenestration solutions.

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Sept 2020
01 Sep 2020