Have you ever watched one of those TV shows that have featured a home that has all the essentials of living a comfortable life and all of a sudden you think of electric bills? You wonder and ask how they are able to deal with costs of living in such an ostentatious house. Then the owner reveals that the whole house is energy efficient. It might be too good to be true for some but it is now becoming a trend in the real estate and architectural industry. The most popular green energy used is solar energy. The Chinese and the Greeks were the first one who predisposed the use of sunlight in urban development methods. From then on, the architectural world has been working with the passive solar building design in order to design the perfect home for people depending on location and weather factors.

One of the common things that homes in countries that experience winter have in common is a heater. A heater is considered one of the necessities during the cold months to keep living spaces warm. Some types of heaters use natural gas or propane but today most of the heaters use electricity. Since the heater is used for weeks or even months for the whole duration of the winter, the demand for electricity is at its peak. Households and even businesses tend to have high electric bills to pay. However, the passive solar thermal building design does not have to deal with such high electric costs for heating. It employs the strategic use of solar energy.

The passive solar building design works with collecting, keeping and dispensing heat all throughout the house through the use of the windows, walls and floors. The energy distributed in the form of heat during the winter. The design includes and efficient system which discard solar heat during the summer season. However, unlike the active design, the passive solar building design does not use any mechanical systems in order to make the heat circulate inside the house. In order to harness the solar energy in order to provide heating to the living space, another law in Physics which states that heat moves from a hot to cold area. An example of this is a heated floor warms up the whole room.

Aside from relying on the law of physics, the passive solar building design also banks on the orientation, design and fixtures of the house. Houses that are built in this design are positioned with an angle of 30 degrees to the south. The homes that are designed under such do not have many corners. Having too many corners will not be an effective design in harnessing solar power. The fixtures, such as the windows also have a great impact on the whole design.

The overhangs present at the windows facing the south allow the sun in during the winter and out during summer. During the summer, the sun angles at 66.5 degrees and as a result the eaves installed will protect the windows. When the windows are protected, there is minimal heat gain from the sun. This keeps the home from too much heat. On the other hand, during the winter, the sun angles at 19.5 degrees which results in maximum heat gain because it reaches the living areas. The heat gain during the winter is important in keeping the home warm despite the cold temperatures.

The energy in the form of the heat from the sun travels from the exterior of the passive solar thermal building designed house to the interior. Inside the house there are four processes that take place in order to collect, store and distribute the heat. One of these is conduction of heat. Heat conduction is described to be heat moving from one molecule to another. Convection is another process that takes place inside the house; it is a process of heat transfer which is applied to gas and liquid mediums. The third process is radiation which can be observed when the sunlight strikes a shiny floor and reflects such light. The last process is storing of the heat.

In the passive solar thermal building design, storing the heat is vital. In order to keep the heat, materials with the characteristic of thermal capacitance are used all throughout the house. Thermal capacitance is defined to be the capability to store heat. Materials that have very good thermal capacitance have great thermal mass. An example of a material that has the characteristic of thermal capacitance is a concrete block. It is worth-noting that the prevention of heat loss is vital in the design. In order to keep the heat from escaping; insulation, draught sealing, airlocks and glazing are important.

During the winter, 25-35 per cent of heat loss is caused by ceilings and roof spaces. To prevent the heat from escaping, the insulation of the roof should be placed next to it. The other 10 -20 per cent of heat loss is caused by floors. Timber floors need insulation underneath, while concrete slabs need insulation at the sides. Another 15-25 per cent of heat loss is due to absence of insulation of walls. As a solution to this, alternative wall construction systems can be made in order to increase the insulation.

Draught sealing is another factor that must not be taken for granted for air leakage leads to heat loss as well. It is important to use air-tight construction particularizing for wall to ceiling and wall to floor seams. The use of draught-proofing strips is also recommended for windows and doors. Home owners can also opt for well-made airtight windows and doors to prevent heat from moving from the inside to the outside. Glazing is another key factor in preventing heat loss. Glazing is an important in keeping the envelope of the building; it transfers radiant and conducted heat. Over-glazing is not good in the passive solar thermal building design. There must be a balance between the heat gain during the day time and night time. If glazing is not properly done, it might decrease the energy-efficiency.

Lastly, air locks are essential in cold climates. It can be placed in laundry, mud, and garage rooms in order to keep its use efficient. In order to keep the efficiency of air locks, there are a few simple tips that can be followed. One of the tips is to have enough space between two doors. Another would be to avoid sliding doors in air lock spaces because they are hard to seal and they are usually left open. It is also wise to use door swings so that the door closes on its own when left open.

It is a popular design which is being adapted all over the world and it has proven to be efficient in reducing energy costs and maintenance while getting the people benefit from the comforts. Aside from saving on costs, the passive solar building design requires very little maintenance. It helps in keeping living spaces warm or cool. It is said to take advantage of the natural energy characteristics of materials and air which is produced through sun exposure.

This is how the green energy of solar power can be used and maximized in the house. It is a cheap way to harness the energy in the form of heat throughout the house. Unlike the active design, the passive solar thermal building design is cheaper for it does not use any mechanical systems to collect the solar energy. Instead of using heaters during the cold or winter season; the orientation, fixtures and house materials can create the perfect warm comfortable atmosphere. It does not only help save in the costs but it also helps the environment. The passive solar thermal building design may look ostentatious but it is actually a home, made comfortable by green energy.