Masonry heaters are wood stoves with the welded steel or cast iron casing replaced by bricks and mortar. They are very efficient at warming an entire house, producing much higher temperatures from their fuel than standard metal stoves. Like all forms of heating, they have certain benefits and drawbacks.
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:
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.
In most cases, we talk about thermal mass as something that absorbs and stores useful heat from the sun's light, releasing it when your home gets colder to maintain a comfortable indoor temperature. However, it is possible to use thermal mass as an effective cooling mechanism.
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.
When you opt for radiant floor heating, you opt for the most efficient, cheapest and most comfortable heating available, especially when you combine it with a solar thermal installation. The big question for radiant floor installation is how to lay out the piping that carries the hot solar fluid through the high-mass heating medium.
Back when modern radiant floor systems were first installed, copper or steel pipes were used. They were embedded in concrete under the floor and hot water ran through them to heat the building. It doesn't take a genius to see where the problems came from:
