Saving Power With Passive Solar Design

If you ever wanted to save electricity and improve the comfort of your home without using any high-tech gadgets, then passive solar design is the answer.

Passive solar design is a clever way of using the sun’s natural heat and light energy in your home. An example is the use of different building designs and materials to effectively cool and heat your home. What’s so appealing about passive solar design is that it requires little upkeep, it is easy to setup, it improves the value of your home, and you can benefit from tax breaks.

How your home was built and what is what built from play a big part in determining its passive solar potential. Ideally it should be built either on a sun-facing slope or on flat land. And if you live in a residential area, any trees surrounding your home should be deciduous to let through sunlight in winter, but shade your home in summer.

When constructing a new home, make sure it is built so that the length of the house faces the sun, allowing the maximum amount of sunlight. Also note how the size, shape and placement of windows will determine the amount of natural heat and light in your home.

So how does the sun heat your home? There are three ways:

1) Direct - the heat from the direct sunshine on an object.

2) Indirect gain - radiated heat from objects heated by the sun.

3) Isolated - the hot air that circulates through your home.

To ensure the most natural heat from the above three sources, a number of large windows should be placed on the sun-facing side of your home, allowing maximum sunlight in.

But there is no point designing your home to let in a lot of natural sunlight and warmth if that energy cannot be stored for later use. Ideally you would want to use materials that absorb sunlight and radiate that heat for a long time. In winter, to get the most out of the natural heat in your home, you could close off cold, unused rooms from the rest of the house, and sit in the sunnier, warmer rooms during the day.

During summer, the right length roof overhangs or eaves can be used to control the amount sunlight and heat in your home. The eaves should be wide enough shade out the intense midday sun, but let the let low-angle sunlight through during dusk and dawn to light up and warm the home. Again, the right trees and shrubs can be planted to regulate the house’s seasonal exposure to the sun.

For current buildings, the simplest passive solar design solution is to replace your windows with modern ones, that use various methods to store up 50% more heat. Although they are 10% to 15% more expensive, they pay for themselves in the long-term from all the power saved to heat your home.

Also known as Low-emissivity (Low-E) windows, double-glazed windows are great at letting through sunlight, but retaining that natural heat inside. Some of them have multiple panes of glass with a gap of argon or krypton gas to store the heat. Also to reduce heat loss, make sure your windows and doors are well-sealed.

What your windows are made from can make a big difference too. While metal framed windows generally conduct heat out the house, wood, vinyl and fiberglass frames insulate the heat better. Always ensure any modern windows bought have labels issued by Energy Star or the National Fenestration Rating Council. These labels provide statistics on how effective and efficient the windows are at retaining heat, which helps you purchase the right windows for your conditions and budget.

So you can see, passive solar design is the effective use of nature and physics to maximize the use of the sun’s natural lighting and heat. Always remember, the point of solar passive design is to reduce your electricity usage and bills. So it is recommended to always weigh up the costs against the potential power savings when installing any passive solar solution at home.