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:
Direct gain passive solar homes have many advantages and disadvantages compared to other approaches. Historically, the first direct gain homes were often a complete mess, because the designers had little understanding of the need to balance things like solar glazing and thermal mass. Modern designs are much better, especially since analysis software is now available to help make the tough decisions.
Thermal walls, or Trombe walls, are the single most flexible passive solar option: they work in any climate and on any home, providing extra heat throughout the night after gathering heat during the day.
As with all passive solar design options, Trombe walls are a great addition to your home design: they retain a lot of heat, helping to reduce your nighttime heating costs throughout the cool period of the year. However, again like all other options, they need to be used correctly or they won't do you any good.
Thermal mass is everything inside a home that absorbs, retains and later emits heat, effectively providing free heating. Like most things in home construction, there are many different approaches to its use.
At first glance, you might think that it's impossible to have too much or too little thermal mass. After all, if there's loads of it, your home will store more heat; if there's very little, you'll still get the benefits of what you do have.
But it's not as simple as that.
In an ideal passive solar world, homes would be built as a long string of single rooms, so that every room would be heated by the sun and there would be no need to transport warmth from warmer to cooler rooms. In practical terms, long houses are rarely appropriate: traffic flow inside such buildings is often difficult and housing lots in towns and cities tend to be square or rectangular, rather than extended oblongs.
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!
Physics is the science that defines how the physical world is structured and how each part of it interacts with all the others. Unfortunately, it's an incredibly complicated science because of this. The world is a very complex machine, after all!
As far as solar designers are concerned, there are some very basic laws of physics that must be understood. If you are a newbie in the solar energy field, here's a brief primer for you.
