Using Passive Solar Windows for Home Heating & Cooling

Installing passive solar windows is a one-time investment that can help you save energy over a long period of time. During summer, it can help keep the heat out and the cool air in. During winter, it can help keep the heat in and maximize the heating rays of the sun.

However, the effects of different climates means that people need to position and install their windows differently to take advantage of solar windows' various properties.

Shaded windows keep the heat out in warmer climates. (Photo credit: Wikipedia)

1. Passive Solar Windows for Hot and Sunny Climates

In hot and sunny climates, glazed windows should be installed towards the south of the house.

This allows the windows to collect heat when the sun is low in the sky during the day. That means the house won't overheat by allowing the sun's rays into the house during peak hours.

You can also use a number of shielding devices such as awnings or overhangs to prevent overheating during summer.

Other windows in the house can still be installed, but they should have a shade or glaze installed so they let less light into the house. Having north facing windows in a hot and sunny climate can also lead to overheating.

2. Passive Solar Windows for Cool Climates

Passive solar design using an unvented trombe wall and summer shading (Photo credit: Wikipedia)

There are two main strategies for heating up a home with passive solar windows in cold climates: trombe walls and using a greenhouse methodology.

A trombe wall is a big wall, usually painted black, which allows you to absorb heat into the house without heat leaking out.

The main concern with using a big window is that while the sun's rays can come into the home and heat up the air, the glass conducts heat so well that it can all escape back through the glass.

The trombe wall solves this issue by trapping the heated air between the glass and the trombe wall, then circulating it into the house before the heat has a chance to escape through the glass.

The greenhouse approach uses similar technology to a greenhouse to keep heated air in the house. You use a large number of windows to let the sun's rays into your house, then you use a controlled timer to circulate the air within your house in a way that optimizes the heat and reduces the amount of heat that escapes through the same glass windows that let the heat in.

 Are Passive Solar Windows for You?

Passive solar windows can work for both hot and cold climates, whether there's a lot of sun or just a little bit of sun.

To determine whether or not your home qualifies for passive solar windows, talk to an environmental contractor in your area. Make sure you get several different opinions to get a definitive sense of whether or not it's worth the investment, as they can be pricey - but they can also save you a lot - especially on heating bills - in the long run.

How to Choose the Right Solar Power System for Your Home

With energy costs rising steadily, more and more people are seeking ways to incorporate solar power into their energy plans for their household. However, there are some things to bear in mind if you want to install a solar power system in your home. Not just any system will do. It needs to fit your energy needs and your property location. Here are some tips.

First, determine if your location is conducive to solar. You need to have an area of your property that faces in a southerly direction - ideally, it will face directly south, but slightly southwest will work. It needs to receive sunlight between 9AM and 3PM. Make sure you observe this area all year round, because a property's sunlight can vary greatly from season to season.

Remember, too, that you can mount solar panels on tall poles and trees, not just your roof. So if an area of your property is shady during the key part of the day, look up - it might be sunnier up higher.

Second, call your utility company and find out what your average monthly use of kilowatt hours is. Then you can determine how many KW hours your solar system will have to generate. (You might choose to have only half of your KW hours replaced by solar.)

Types of Home Solar Systems

In order to narrow down what sort of system you need, it's important to familiarize yourself with the different types. Most homeowners choose to be tied in to the power grid, because a stand-alone system can get very complicated and expensive. It is an option, however.

Flat-plate solar thermal collector, viewed from roof-level (Photo credit: Wikipedia)1. Photovoltaic solar panels
These are what most people think of when they think of solar power. They are flat panels that sit on your roof. Generally, photovoltaic systems can power appliances and lights only, not heating and cooling.

The power generated is usually tied in with the conventional power grid, and this is viable option for most solar power users. If you are tied in to the grid, you do not need a battery back-up for night-time and other times when the sun is not shining. The conventional power company becomes your back-up when you are tied to the grid.

2. Solar heating systems

There are active and passive solar heating systems for our home. Passive solar heating uses conduction, convection, or radiation to move sun-generated heat throughout the home. Active solar heating collects the sun's heat in some kind of air or water reservoir, then pumps it throughout the home.

Obviously, depending on the system you choose, these are usually less costly and easier to set up and maintain than a solar panel system. You may choose to go less intensive and just use passive or active solar heating, or you may add solar panels as well and reap the benefits of a combination of these systems.

For a great resource for both solar D.I.Y. info, and pre-made solar power system kits, check out Solar Sphere's website.