Homily Magazine

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.

If you plan to build a new home, make sure it is designed so that the majority of it faces the sun. Also, the size, type and shape of your windows will affect how much sunlight and natural heat your home gets.

So how exactly does your home warm up from the sun? In 3 different 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 maximize the sun’s natural heat from all three sources, it is best to use large windows on the sun-facing side of your home.

All that sunlight and heat in your home is useless, if it cannot be stored and used when the sun is set. The solution is to use heat-absorbent flooring and walls that carry on radiating heat long into the night. A simple way to reduce power cost in winter is to locate to rooms in your house that get the most sunshine at certain times of day. Also, shady rooms should be cut-off (their doors closed) from the rest of the house to retain heat better.

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.

Double-glazed or Low-emissivity (Low-E) windows let solar heat in, but keep in the indoor radiant heat. Another way to reduce heat loss is to ensure tight seals around all windows or by using multiple panes that have gaps between them filled with argon or krypton gas.

The type of windows frames you use can also make a huge difference. Metal frames should be avoided since they draw heat out of your home in winter, but heat up your home in summer. It is better to use wooden, vinyl or fiberglass frames to insulate your home better. When you do buy modern windows make sure they are labeled by the National Fenestration Rating Council or by Energy Star. That way you will be able to buy the right windows for your needs and budget.

The whole idea behind passive solar design is to use the sun’s natural heat in such a way that it reduces your energy consumption and expenses. So before going out and getting the latest and greatest passive solar design and products, always weigh up the cost involved with how much you will save in energy bills in the long-term.