Daylighting is a building design strategy to use light from sun. Presence of natural light in an occupied space brings a sense of wellbeing, increases awareness of one’s surrounding and also increases energy saving potential with reduced dependence on artificial light. Appropriate use of windows, skylights, clerestories, and other apertures in the building provide means to harvest daylight.
Remember that, more the sunlight that enters the building, more the heat that needs to be dealt with. Thus, by placing apertures correctly, nature can work with you. Integrating daylighting with artificial lighting can considerably reduce energy consumption, but at the same time may lead to higher air conditioning loads due to heat gain. Thus design consultants and decision makers need to appropriately balance daylight harvesting features and minimize solar heat gains. Hence, daylighting becomes an integral part of a building design strategy from early design phase to lower the energy consumption of a building, imperative to advance NZEB design goals.
Orientation and form for daylighting
Buildings can be located and oriented to take advantage of sun’s movement throughout the day, as well as seasonal variations.
Amount of daylight that enters a room depends on the window location and its dimensions.
Location, form and dimensions of shading devices
Daylighting is the one of the cornerstones of energy efficient building designs. Several studies have proven the benefit of daylighting, linking it to higher comfort, productivity, and feeling of well-being in schools, offices, and hospitals.
An appropriately designed daylighting features will provide better indoor environmental quality, improve building occupant performance and reduce the building’s energy consumption at the same time. Daylighting can significantly impact the energy use of a building by reducing the lighting energy demand by up to 20-30%.
NZEBs, which must be designed for 100% daylight potential, can virtually eliminate daytime lighting energy use in most spaces. The resulting saving in lighting energy use also reduces cooling load while providing a better work environment.