| uld you like your new house to be warm in the | | | | throughout the year. In the summer, the Sun |
| winter and cool in the summer without the use of | | | | angle (also known as altitude angle) is greatest. |
| air-conditioning, heating, or even solar power | | | | That is to say, the sun cuts a high arc through |
| panels? You can. It’s called passive solar, | | | | the sky. In the winter the altitude angle is lowest. |
| and is all about how you design your home and | | | | The Sun cuts a low arc through the sky. The |
| where you place it on your property. | | | | angle changes every day. On June 21, the longest |
| The first thing to understand about passive solar | | | | day of the year, the Sun angle is greatest. On |
| is that it doesn’t have anything to do with | | | | December 21, the shortest day of the year, the |
| solar panels, photovoltaic cells, or any other | | | | sun angle is lowest. |
| technology. The whole idea is to build and situation | | | | Thus, the eves on your passive solar home act |
| your home in such a way as to harness a | | | | as an automatic on-off switch for your passive |
| maximum amount of the sun’s energy in | | | | heating / cooling system. It turns the Sun |
| the winter, while blocking the sun’s rays | | | | power’s effect on your home off for |
| from heating your home in the summer. And you | | | | most of the day in the Summer, but leaves it on |
| do it all simply by understanding how the Sun | | | | for most of the day during the Winter. |
| moves where you live. | | | | Here is simple picture by the Northeast |
| How Does Passive Solar Work? | | | | Sustainable Energy Association (NESEA) that will |
| There are three main elements that make a | | | | solidify the concept of passive solar home design: |
| passive solar home different from a conventional | | | | Get it now? |
| home: South-facing windows; a ledge of a certain | | | | With the exception of adding a slight overhang |
| length and angle above those windows; and a | | | | above South-facing windows, there isn’t |
| mass-wall. The ledge above the windows is short | | | | much you can do about turning your existing |
| enough and placed at such an angle as to allow | | | | home into a passive solar house without major, |
| the winter sun to shine in and fill the mass wall (or | | | | expensive renovations. But next time you buy a |
| thermal wall) with heat during the day, which is | | | | home, before moving into one of those |
| released as the house cools at night. But the path | | | | add-water monopoly houses in the new |
| of the sun is at a higher angle during the summer, | | | | subdivision, think about how inefficient their |
| allowing the ledge to block the sun from directly | | | | designs are. Most of the time you’ll see |
| shining into the house. The mass wall stays cool, | | | | that the South-facing windows are either hidden |
| as does the house. | | | | from the sun by the house next to you, or two |
| Ever feel like your house is hotter at night during | | | | few, which would cause your home to be cold in |
| the day? Does it get down-right stuffy in the | | | | the Winter and require more energy from the |
| Summer? Does it feel hotter inside than it does | | | | furnace to heat. Or you may notice that the |
| outside? That’s because the walls and | | | | south-facing windows are in full view of the Sun, |
| floors of your home have been collecting heat | | | | but there is no ledge above the area, thus |
| from the sun all day, which has been shining in | | | | allowing the Sun to heat up your home like an |
| your windows in the middle of summer. At night, | | | | oven during the summer. |
| due to a process called convection ( ) the heat | | | | The ledge, window and mass wall are probably |
| stored within the walls and floors is released into | | | | the three most important concepts of a passive |
| the air, thus heating the room and making it | | | | solar home. But it goes well beyond that. For |
| hotter inside your house than it is outside. If you | | | | instance, knowing that heat rises, there are ways |
| have this problem, you do what most of us do | | | | to control the flow of air throughout your house |
| and turn on your air conditioner and/or fans. This | | | | so as to take full advantage of cooler air in the |
| is hard on the environment and increasingly | | | | summer and warmer air during the winter. All it |
| devastating to your pocketbook. And it’s | | | | takes is a few well-placed vents that can be |
| all because the people who built your house | | | | switched open or closed depending on the time of |
| didn’t understand building concepts that | | | | the year. If people demand this kind of |
| people around the world understood thousands of | | | | forethought from their builders we would require |
| years ago – you work WITH the earth; | | | | only a fraction of the fossil fuels being used to |
| not against it. | | | | cool and heat our homes. If you combine passive |
| The paragraph below is used with permission | | | | solar design with a few solar panels, this often |
| from John Schaeffer and Real Goods, a solar | | | | results in the power company paying YOU each |
| panel installation company working in Colorado and | | | | month for the extra energy you’re |
| California: . It was taken from the Real Goods | | | | sending back into the grid. Everybody wins with |
| Solar Living Sourcebook: : | | | | passive solar home designs. |
| The angle of the sun from the horizon changes | | | | |