The Sun is the most powerful source of energy in our Solar System and without its light and heat the Earth would be just another inhabitable Planet. The problem we find today is harnessing its energy for our own use. Although there are many products being manufactured such as Photovotaics for Energy to Electric conversion one of the first known and easiest methods of harvesting the Suns energy is passive solar heating.
This method of harvesting can be the least expensive and the most versatile and ranges from almost no intervention to elaborate solar farms that capture the suns heat and generate electricity from steam turbines.
Unfortunately finding a steam turbine to match the color of your house is next to impossible but there are things that the average home owner can do to make use of this free energy source.
Passive solar technology is described as being able to capture the solar heat without or with minimal mechanical intervention. The reason behind this is to maximize the benefit without cost.
The simplest form of Passive Solar Heating is just opening you blinds on a Fall, Winter or Spring day to allow the Sun to enter your home. Even when the temperatures are cold outside the Suns Radiation will enter into the home and be absorbed by furniture, walls and flooring materials. In the evening when the Sun goes down the heat within these items will escape back into the home.
The next step up would be to install materials in the home such as brick and stone walls or slate and tile floors to act as a thermal mass. Stone and Ceramic materials have a low transfer rate and once heated will store and emit the energy over a long period of time.
To understand the difference in materials that can be used you can think of a pot on your stove. A heavy cast iron fry pan takes a long time to heat up but once heated it will store and transfer the heat evenly. A thin aluminum pot on the other hand can be used to transfer the heat to water in the pot to speed the time to boiling but once the water is emptied the aluminum pot will cool quickly. For this reason if you were to choose between aluminum and cast iron as a thermal mass or bank to put our solar heat in for later use we would choose the cast iron.
There are many other factors that you should consider if you are planing a new home and have the ability to choose materials and the homes location.
To maximize the amount of energy you can capture you should position the home on the south or southwest side of a hill if you live in the Northern Hemisphere and if you are below the equator you would want to be on the North side. This way you will receive more of the winter sun.
The homes windows should be maximized on the sun facing side and minimized on the side that does not get exposure. This is to allow light into the home and also because windows on the non facing side will have a lower insulating R Factor then a normal wall with insulation. Although this can be somewhat difficult to accomplish with planning you can use the non facing side of the home for Utility, Garage and other less used rooms.
Landscaping is also a concern and you should have a preference for Deciduous trees (with leaves that drop) on the sun facing side of the home that will provide protection from the sun in the summer months and then lose their leafs in the winter to provide good sun penetration into the home. On the opposite side you can use Pine trees to act as a buffer from winds which will rob the homes heat.
Along with direct gain solar heating as we have been exploring where the sun heats an item and it radiates out its heat to the same location there is also indirect gain where the heat is captured and then passed on to another part of the home for storage or immediate heating.
This is where Passive Heating needs an assist. Some home designers have found by building a basement with river stone or similar materials you can capture heat in the exposed areas of the house and with fans and ducts transfer the heat into the basement. Heat is captured during the day by using fans to send warm air to the stone bed and in the evenings the circulation brings that stored heat out of the basement into the home.
Elaborate systems like this that require a lot of planing and are not realy suitable for remodeling projects unless you are willing to add another room to act as a capture device.
Another option is using a solar hot water heater to capture heat out in the yard or on the roof of the building and then instead of heating water the captured heat is passed through a radiator where a fan blows the hot air into the building. A project of this type is not difficult if you us heat sensors that will protect outside fluid in the lines from freezing. Roof systems usually have a drain back protector where if electricity to the water pump is lost the fluid returns to a tank in the building.
As we have described Passive Solar Heat can be captured for use in your home and it doesn’t always mean elaborate construction or expensive devices are needed. If you simply make sure that your blinds are open to allow the sun to enter your home during the day you can see a great advantage. If you are thinking about installing new flooring you may want to look at a ceramic or stone material that will capture the heat. Skylights are also a great way to improve both the amount of light and heat. And remember in the summer you will want to take the reverse steps of closing blinds on the sunny side of the house to reduce your cooling costs.
Remember every advantage you can take means less money out of your pocket.
Something as simple as opening a blind could pay back as a night out or a free pizza.
For more information on Passive Solar Heating
please check our book store
The Solar House: Passive Heating and Cooling
Passive Solar House: The Complete Guide to Heating and Cooling Your Home
The Passive Solar Design and Construction Handbook
How to Build and Benefit from a Passive Solar Collector as a Space Heater
Passive Solar House: The Complete Guide to Heating and Cooling Your Home