Regardless of what kind of backup heating system you put in your passive solar home – forced-air, radiant floor, baseboard hot-water, or something else – you're going to need a source of heat. And that means a high-efficiency boiler or furnace.
That title might fill you with apprehension and, in many ways, you'd be right: analyzing such a complex thing as a home's energy performance without using software is a daunting task. But it is possible. There are even several books which include worksheets and detailed descriptions of how to build a more accurate assessment than the one we'll outline here.
If your passive solar home is properly designed and everything is optimized, one of the most cost-effective backup heating systems available may be wall-mounted space heaters. For homes which only need an occasional top-up of heat or for infrequently-used rooms, they are ideal.
Analyzing your passive solar home's energy performance by hand is long-winded, cumbersome, and prone to error. Between ten and twenty years ago, a variety of software tools appeared on the market, ranging from DOS-based utilities to basic Windows apps.
Over time, most of these programs have disappeared. Some were discontinued because they weren't popular enough, some vanished because they were based on obsolete operating systems, and others were simply discontinued through lack of support.
Modern wood stoves are not simple metal boxes to burn fuel in. They are much more efficient than traditional fireplaces and can be just as attractive. Stoves also rely on a renewable source of energy. Most modern wood stoves fit into one of two categories: radiant or circulating.
Designing a passive solar home is not the end of the road for sustainability. There are many more choices you can make to improve your home's sustainability and, at the same time, reduce the impact of traditional living on the environment.
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.
There are two main ways you can improve your home's ecological impact when it comes to water: installing alternative systems for domestic and outside water use, and implementing an alternative wastewater system.
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.
