Here Comes the Sun: Passive Solar Parking Lot

Here comes the sun  (dadda dum dum) …No, I’m not building a parking lot–it’s just that I’ve been confusing myself with a whirlwind of research about passive solar home design, so this post is a parking lot where I can post some of the things I’ve been looking at so I don’t lose them, but not lose my wits either, by taking on more than my brain can handle when I’m just now starting to be able to think in 3-D.

Basics: South-facing is good.  For reasons I don’t understand, there’s a difference between polar north and magnetic north.  Whatever– at the National Geophysical Data Center (NGDC) site I was able to generate a map that shows magnetic north and south for my site:

solar_declination
source: http://www.ngdc.noaa.gov/geomag-web/#declination

Slightly off-topic, but in the same color scheme, I was also able to generate something called a “wind rose,” which is a graph depicting the prevailing wind patterns at a given place in a given time span.  This was pretty cool.  The State Climate Office on North Carolina has data from the Asheville weather station dating back to 1948, so I entered my birthday as the starting value and basically have a map that shows the wind of my lifetime in that spot:

windrose asheville nc

Being able to visually depict the winds of the past like that reminds me of something I heard, probably on Radiolab, about how when dogs pick up a scent, the information they are able to gather is not just spatial, eg “squirrel was here”, but temporal and directional: “squirrel was here an hour ago and then moved off in that direction.”

Anywho, the practical impact of the wind rose and the magnetic north thingy will be to try to orient the house so that it stays warm in winter and cool in summer and catches a nice breeze where we want a nice breeze.

Another thing I learned is that the sun is higher in the summer sky and lower in the winter sky, so one might want to use eaves and other tools to protect the house from the high summer sun’s hot rays but try to maximize the winter sun’s lower rays.

I found this photo, which gives an overview of all the factors to consider, and I’ve downloaded a paper (http://www.ibpsa.org/proceedings/BS2009/BS09_1397_1404.pdf) from there for when I’m ready to dive in further.

There are a lot of unknowns for me, though. Given that the lot is so wonderfully wooded, and since this isn’t designed as a permanent year-round dwelling and won’t be heated except by the sauna stove, (we winter in Asia), I am thinking we may just want to take all the sun we can get.

When I’m ready to learn more http://www.builditsolar.com/Projects/SolarHomes/guidesps.htm looks like another really good source of info.