> I was hoping that perhaps someone on the list could tell me the proper roof
> overhang for a passive solar room for south central Kentucky about
36degrees
> North Latitude and 84 degrees west longitude.
>
> Frank
Hi, Frank.
It's not too hard, but I don't know if there are any charts on it. Let me
give it a try. I'll start in a general way; you can ask me specific
questions if I get confusing.
You need to know two angles. The sun's angles at the winter solstice and
at the time of year when you don't want it in the house any more in the
spring, or start wanting it in the fall, which often involves some
compromise as the sun's angle does not always match up with outside
temperature.
Then you need to make the angle from your overhang to the top of your
window about the same, or less, than the sun's lowest angle (at the winter
solstice). This lets the most amount of sun come in during the winter.
And you need to make the angle from your overhang to the bottom of your
window about the same as the angle you chose for when you want to the sun
to stay out in the spring and come in in the fall. This controls the sun
during the hotter months to prevent overheating.
That's it. Figuring out the two angles takes some math and some basic
information about the sun and your lattitude. Figuring out the angles on
your house plan takes some basic geometry.
Good Luck! I did this for our house, and it works beautifully!
Eric:
