A big part of the passive solar home equation resides in cutting down on how much heating and cooling you need. The lower your demands, the bigger the percentage you can cover with renewable solar energy. There are two main culprits of internal heat gain in the average home:
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If you're designing a direct gain passive solar home, you will need to maintain a careful balance between two vital parts: the amount of glazing on each side of the house and the amount of thermal mass available inside to store and later release heat. Getting the glass-to-mass ratio wrong will result in too much or too little heating.
One of the aspects of passive solar house design that surprises many people is the need for shade. If your heating depends on sunlight, why would you block it? Because not all sunlight is beneficial to a passive solar home – the high summer sun, in particular, can produce far too much heat, requiring some kind of shade to stop your home turning into an oven.
One of the most infuriating aspects of passive solar design is that one size never fits all. A design that works perfectly on your site may be ineffective two miles away on the other side of a hill, on higher ground, or in a rural area.
With that in mind, regional adjustments are not too difficult. The basic design can stay much the same in areas with similar climate, but you will have to adjust four factors:
One of the aspects of passive solar house design that surprised many people is the need for shade. If your heating depends on sunlight, why would you block it? Because not all sunlight is beneficial to a passive solar home – the high summer sun, in particular, can produce far too much heat, requiring some kind of shade to stop your home turning into an oven.
One unusual feature of many passive solar homes is that they are partially buried. Given the natural human dislike of living underground, this often strikes people as a "caveman" approach to efficient living but, in reality, it is an efficient means of conserving potentially enormous amounts of energy. And no, living in a home that uses earth berming or earth sheltering is not like living in a cave!
One of the most important factors in energy efficiency is home insulation. And one of the most important parts of insulation is keeping the material dry. There are two reasons for this:
Most, if not all, proponents of solar energy will exhort the long-term value of installing passive (and active) solar systems. The return on investment over the life of the installation is always impressive on paper and professional installers will happily spend hours explaining how the cost works out as a tiny percentage of your income. Then they'll just as happily bill you five figures!
Windows have undergone a huge number of advances over the last few decades. While most construction methods and materials have remained the same, windows have changed from heat-sucking drafty holes to efficient light-capturing devices which help improve energy efficiency.