Is a passive solar heating and air system right for you?

Solar power is more abundant than any other source of energy on the planet. Thus, building households with solar energy systems can be advantageous because they are more environmentally friendly and decrease dependence on more difficulty obtained resources.

In an advanced solar home, this energy can be converted into electricity and used for all of the same purposes for which we normally use electricity: lighting, heating and air, hot water, etc. The downfall to these technologically advanced systems is that they can be far more expensive than traditional methods.

But there are other sun-fueled options, including passive solar heating and air.

While the most advanced solar power systems convert the sun's energy into versatile electricity, there is also the electricity-free option of passive solar power. Passive solar heating and air relies on architectural structures to harness and distribute heat for winter and to block and let out heat during summer.

To heat a passive solar home, the natural heat from the sun is absorbed into a dense concrete wall called a trombe. From here, it eventually seeps into a concrete base under the floor. When the sun goes down, the heat beneath the floorboards rises naturally and warms the house from the bottom up.

The upside is that this method does not require expensive conversion systems to convert the sunlight into electricity to then heat the house. The heat remains in its initial state — heat — to get the job done. But how does a passive solar house get cool?

Unfortunately, the passive cooling system is limited. The most that can be done to keep these homes cool is to equip them with heavy insulation, to limit humidity and to strategically place windows on the sides of the home that won't be hit with direct sunlight during the hot summer months. These windows can be opened to cool the home, but in excessively hot and humid climates, a backup traditional cooling system is required to maintain comfort.

Likewise, a very cold location that is prone to snowstorms or does not receive enough sustained sunlight would be unable to absorb enough sunlight to properly warm a house.

If it has been determined that your geographic location is suitable for a passive solar heating and air system, it is time to consider more specific requirements.

First, the home must be built in a somewhat wide open area, free from any high hills, mountains or forests that might block sunlight for a prolonged period of time. Second, the "trombe wall," into which most of the energy will be absorbed, must be facing south to optimize the amount of exposure it has with the sunlight throughout the year.

Due to the fact that a passive solar heating and air system essentially lies in the foundation of a home, it is extremely difficult to impossible to simply install such a system into an existing house. In most cases, the house would have to be originally built with the goal of harvesting solar energy in mind.