How a Skylight Window Can Naturally Ventilate Your Home
A skylight window can help you to naturally create a cooling airflow throughout your home without the use of fans or other devices. All you need is a low-lying aperture, an open window for example, and a ceiling-level opening.
This natural process is called stack ventilation. It relies on the principle that hot air is lighter and more buoyant than cooler air, so it thus tends to rise upwards. A skylight window allows you to use this basic principle to create a vertical air flow through your home. For it to work, the air inside needs to be warmer than that outside. This type of ventilation is perfect for cooling your home during the evening after a hot day. It works like this.
Air enters your home through an opening such as a window for instance. As you are trying to create a vertical flow or passage, this inlet needs to be low-lying. Once inside, the air warms up through contact with the surrounding atmosphere. It then travels upwards and gathers around the ceiling before flowing out the open skylight window. This creates a vacuum effect inside the home that suctions more oxygen through the lower windows. The overall result is a vertical breeze or ventilation flow, without using fans or other mechanical means.
Finetuning the Effect
Stack ventilation provides an ideal way to cool and aerate your home, particularly on still days when you can't rely on wind. It offers a means for you to produce your own cooling breeze. You have a lot of freedom in setting up a passage for the air flow as you can open any low-lying window or door, plus then open a window skylight. For the best effect, the distance between the low and high openings should be as great as possible.
Making Use of a Breeze
Although you don't need a breeze to produce this natural ventilation, you can make use of one for a stronger effect. Allowing the wind inside by opening a window that faces the breeze, increases the air pressure within the home and forces oxygen out the skylight more quickly.
Skylight windows are ideal for helping you to naturally ventilate your home without accruing energy costs. While you don't need a breezy day, it does rely on a temperature difference between inside and outside your home. Stack ventilation is different from wind ventilation, which relies on a breeze to blow inside via windows or vents and then to exit out the other side of the home.