The visible spectrum consists of white light which is a combination of seven main colours called ‘VIBGYOR’ which stands for the colours, Violet, Indigo, Blue, Green, Yellow, Orange and Red. These Colours, depending on the colour and intensity have deep psychological effects on a person’s moods and hence have to be used sensibly for creating a good, positive environment. The effect of colours has been explained under Vastu Colours of a House.
In climatology, heat and light are intrinsically linked. Blind belief in looks and sometimes in light has led people to have big windows, resulting in heated-up interiors. Incidentally, one major shift in Indian buildings has been from small wooden windows to large sheet glass windows, without considering why small openings were provided for centuries, nearly all over India.
In the northern hemisphere, the sun is always to our south. That means that whichever wall is facing south will receive the most sunlight. To maximize the sun use, place the longest side of your house facing south.
Vastu Shasta has a scientific basis. It is therefore, worthwhile to understand the importance of these Vastu factors, their positive and negative effects on Man and how the positive effects can be used to advantage in the design of his dwelling. All this has been explained under the following headings. Typically, a south-facing home gets sun for most of the day, especially at the front of the house, and is therefore usually brighter and warmer.
In urban contexts, it may be easier to employ skylights with adequate hot air vents. However, among the best to get light without heat is the idea of internal courtyard with minimal openings to outside – no glare, equal distribution of light and cross ventilation, all together. No wonder, our forefathers realised this and lived in courtyard houses. We need to modernise this concept for application today.
Verandahs, vegetation, designed roof overhangs and such others are necessary. Among the problem fronts is the western facade, which receives solar energy during afternoon hours, heats up, conducts it inside and makes the indoor warm during the evening and night, just when we need to use them most. There are many ideas like tilting the building to best orientation, using materials with thermal mass or designing the type of opening which help in mitigating heat due to solar radiation.
On an average, from 10 a.m. to 3 p.m., there is maximum heat gain through roof conduction and oblique light penetration through the windows. During other times, light and heat enter through wall openings more directly. Appropriate shading of openings using khas khas, staggered walls, fins, roof overhangs and such others need to be employed. On a daily calculation, maximum heat gain comes from the roof; hence it should be properly designed and treated.
The invisible spectrum flanks the visible spectrum on either side and consists of the Ultra Violet (Chemical) Spectrum and the Infra-Red (Thermal Heat) Spectrum. The Ultra-Violet (UV) rays have a shorter wavelength than the visible light rays and are invisible. They kill bacteria and aid in the synthesis of Vitamin D in our bodies. The Infra-Red rays have a longer wavelength than the visible light rays and are also invisible. They are the cause for the heat of the sunlight. Vastu Shastra has a scientific basis. It is therefore, worthwhile to understand the importance of these Vastu factors, their positive and negative effects on Man and how the positive effects can be used to advantage in the design of his dwelling.
North- or north-east facing properties are considered the most desirable because they get the most direct sunlight through the day, especially in winter when the sun is at its lowest. In an urban area where sunlight is at a premium, this can make a world of difference. One of the most important energy efficiency factors in any home is its orientation. Believe it or not, how a house is oriented in relation to the sun can have a dramatic impact on heating and cooling – the largest energy contributor in most homes.
The physical and psychological benefits of appropriate amounts of natural sunlight are now undisputed. There are too many positive aspects of natural light to overlook. The question is no longer are the sun’s rays healthy but rather how to get as much of that healthy natural light into the residence so that all kinds of good things can happen. Natural lighting is a magnificent benefit provided by nature. Anything that reduces the burning of fossil fuels to produce electricity is a benefit to the environment. By increasing our home’s exposure to the sun with modern, thermal, energy efficient windows and doors, creates a healthier, happier, more comfortable and more sustainable home.