Passive Solar Home Design

If you're in a hurry, you can jump to the PASSIVE SOLAR HOME DESIGN ESSENTIALS.

Mothers, help your children grow up to be explorers!

What we notice is that kids who don't get to explore nature don't grow up to have what we call common sense.  Common sense is what tells you that heat rises, that black rocks are hotter than white rocks in the sun, that a single pane of glass transfers the cold from outside moreso than an adobe block.  Common sense tells you that a house with lots of windows on the cold north side will take a lot more energy to heat than one without,..... and that allowing sun to shine through southern windows and hit a dark concrete floor will heat your living room in a wink, for free.

If you were one of those kids who didn't get to explore and ask questions, then start now.  Why is one restaurant always cold?  What knucklehead pointed their heater blower at the single pane glass windows?  Is your black dashboard hot enough to fry eggs after sitting in the sunny parking lot with windows rolled up?   If you're on a hike and you get a toothache, where might you find something really hot to put on your cheek?  Where do you cool your beer or water bottle?  Does a shady spot in the creek work better than a sunny spot in the creek?  Does the color of the container make a difference?  Is the creek flowing more quickly at its widest, most shallow section, or at it deep and narrow spots?

It's mainly thermodynamics, my dear Watson....and gravity.

Passive solar home design is nothing more than using common sense to design a house that will be warm in winter, cool in summer and will use energy very efficiently.  Passive solar design is working with the laws of nature instead of against them. Heat rises, unless it is blocked by something that doesn't transfer heat easily.  Heat and cold can be stored in mass.   Dark colored mass optimizes a substance's ability to absorb light and heat from the sun. Various substances have different abilities to store energy or transfer it.  Some substances are better suited for insulating from cold and heat.  Water flows downhill on its own, most easily in a straight line.

Humans have been building houses with faces that look like "mama" for a long time.  Why is that?  We get hung up in what it looks like, not how it functions.  Adults are as susceptible to peer pressure just as children are, compelled to buy what looks like what other "respectable" people buy.  But buying or building a house based on what it looks like is like picking a partner based only on looks.   Somebody's gonna pay.

Design can be the fun part of house building.  There just needs to be a balance between looks and function.  The challenge is to find ways to incorporate common sense—all you know about energy efficiency—into layout and materials.

Whatever you do, don't turn the design job over to someone who doesn't appreciate the Laws of Nature.  Does your architect or designer get a kick out of working against these simple laws?  Red flag.  Why not spend some time, years even, thinking "out of the box", and then design your energy efficient home yourself.

Study house building techniques in very hot, dry climates, where every resource is dear.  Desert living draws on creativity and resourcefullness.  Building with a small budget can stimulate creativity and recycling of materials.   Research building styles in places that have too much cold and wet.  How do they allow for water drainage and how do they insulate their homes?

 

 

 

 

 

Make a list of the climate elements that your house will need to deal with. Consider the need to deal with   heat, cold, water, lack of water, winds, lots of cloudy days, heavy snows, potential for forest or grass fires, seasonal hurricanes.  How can you prepare your home to handle these elements without using a lot of energy?

What resources are available nearby?  What's the trade-off  between using a super insulating, recyclable material which is not available locally and the gas that it will take for it to be shipped to you?  How much energy does it take to manufacture that super material you want, and what kind of off-gassing of toxic chemicals can you expect to live with?  Ask questions of yourself and your designer.

Passive Solar Design Essentials

• Use a basically rectangular shape set longwise on an east-west axis, so that you have long southern exposure.
  
• South face should receive sunlight between 9 and 3 during the winter season.
• Rooms that need the most light and heating and cooling should be along the south face of the building.  Less frequently used rooms or rooms with natural heating elements (like kitchens and utility rooms) should be located on the north.
• An open floor plan is best for heat and cool transfer between rooms.
• Use shading to prevent summer sun from shining into the interior.
• Make good use of the heat that rises.

Optimize passive solar heating with:

• South facing glass.
• Thermal mass to absorb, store, and transmit heat during winter.  During summer, thermal mass stores and transmits the cooler temperatures brought in by attic fans or from the earth that the house sits on.
• Dark color of thermal mass to absorb heat, light colors to reflect it away.
• Design elements that allow for heat's natural rising to distribute heat.

An excellent source of in-depth information on passive solar design is available at The Natural Home.