Benefits of daylight
The benefits of having abundant daylight in our homes are well documented. Studies show that students learn better, adults suffer less Seasonal Affective Disorder (SAD), and older people have less trouble reading and getting around when rooms are filled with daylight. But aside from documented psychological and physical benefits, it's obvious that living and working in a naturally brightly lit space just makes life feel better.
Light from above makes all rooms more functional and liveable. Our kitchens become more enjoyable when they are bright, cheerful and free of cooking odours and heat and when moisture is allowed to escape via extractor fan and through venting roof windows. A roof window will let in twice as much light as an equivalent sized vertical window.
Daylight purely by façade windows has its limitations when the building is deep, no matter how much glass is included in the façade. A roof window provides a greater amount of light falling into the room when situated overhead.
Indoor climate
By increasing the amount of glazing within a building, there is a potential that the building will receive too much heat from solar gain.
It is therefore necessary to design the location of the windows in areas that promote rapid air movement when opened. This will expel the warm air quickly and reduce the temperature rapidly within the building.
Designs that include cross ventilation and the chimney stack effect will maximise efficient ventilation.
The stack effect is temperature induced. When there is a temperature difference between two adjoining volumes of air the warmer air will have a lower density and be more buoyant and will rise above the cold air creating an upward stream of air. The stack effect only exists when the indoor temperature is higher than outside temperature. It is the difference in pressure which drives the airflow.
Warmer indoor air rises and escapes the building at higher apertures, whilst colder denser air from the building enters the building through lower openings. Stack effect increases with greater temperature difference and increased height between the lower and higher apertures.
Controlling Daylight
VELUX has an extensive range of blinds especially designed to control not only the amount of light the room receives but also its direction and quality.
External shading for example awning blinds can help reduce the solar gain within the room allowing the living envoirment to be full of daylight but without the excessive heat.