yes

180 days – the sun rises south of east for half of the year and north of east for the other half of the year

two – only on March and September 21

two- the equinoxes

no – at the equator, every day of the year has 12 hours of daylight and 12 of nighttime

it varies with latitude

at the equator the sun rises 23.5° north of east on June 21 (azimuth of 23.5⁰)

yes

At the Arctic Circle the sun rises 90⁰ north of east on June 21 at midnight (azimuth of 180⁰). Going north of the arctic circle, the sun shines directly from north for increasing number of days until at the north pole it shines directly into north windows at midnight for half of the year.

At the north pole the altitude of the sun on June 21 is 23.5° all day long.  On December 21 the altitude is -23⁰ all day long.

In the summer one has 24 hours of daylight with the sun revolving overhead at constant altitude angles. In the winter there are 24 hours of nighttime with the possibility of seeing the northern lights. However, at the equinoxes, there will be 24 hours of sunset or is it 24 hours of sunrise? Would that not be a great time for a honeymoon at the north pole?

Heading south from the north pole, the sun is higher and higher in the sky with June 21 at 12 noon always the highest altitude angle.  At the Tropic of Cancer the sun reaches 90⁰ altitude for the first time (i.e. the sun is overhead for the first time) on June 21 at 12 noon.

Fixed overhangs are not very good in climates where both winter heating and summer shading are required. After all, the sun takes the same sun path on March 21 and September 21. A fixed overhang cannot both fully shade and fully expose a window to the sun if the sun is at the same altitude. Any fixed overhang will not shade enough in the summer, if it is designed to collect most of the winter sun, and vice versa.  Thus, a fixed overhang is a poor performer in any climate were much heating and cooling is required, and the world now needs high performing building systems.  Consequently, in such climates south windows should have movable overhangs such as retractable awnings.

There is no shading system for east and west that can fully shade windows while maintaining a good view. Vertical fins perpendicular to the windows do not shade well, and they reflect daylight to the right and left creating glare. Not only do louvers shade east and west windows a little better, they also reflect the light up to the ceiling for superior daylighting.  Slanted fins work better than perpendicular fins but restrict the view even more.  Thus, avoid east and west windows whenever possible, since there is not any good shading system for those windows.

yes!!!!!!!!

no!!!!!!!

Use clerestories facing south where winter heating is required and facing north where winter heating is not required.

yes!

It is possible to design a solar responsive building at the same cost as a conventional building and yet use less energy and thus cost less to operate. A “free lunch” can be achieved by the informed use of the following strategies:

 1. Form and orientation of building

 2. Size and placement of windows as compared to the same number of windows equally distributed around the building as is quite typical.

 3. Using white or very light colors for the roof and exterior wall surfaces (a white roof has 50% less heat gain than a black roof and a white wall has 35% less heat gain than a black wall or 25% less than exposed red brick)

yes!

The strategies mentioned in question 19 will even reduce the first cost because the cooling system will be smaller (i.e. smaller compressor, AHU, and ducts). (borrowed from Amory Lovins)

It is much smarter to live on and east-west street because then most windows will face mainly north and south, while on the north-south street the window will face mostly east and west and will therefore be blasted by the summer sun while getting little help from the winter sun.

The houses on the east-west street not only save in heating and cooling energy costs, but they can also have a smaller cooling system and therefore cost less to build.

No! Not only do deciduous trees shade anywhere from 20 to 60% of the winter sun by their branch structures (depends mostly on the species of tree), but they will shade the roof in the summer which is unfortunate since the south facing roof should have an active hot water collector and eventually PV if not right away.

Deciduous trees are best on east and west windows that need a maximum of shading in the summer.

yes.  Although shading north windows is not the top priority, the solar exposure of north windows (½ of each year) does contribute to the cooling load. Windows on the first floor may be shaded by trees and neighboring structures, but windows on a multi-story building will be exposed to the summer sun. Ironically, the solar exposure of north windows increases with latitude. Thus, north windows in Canada may require more shading than windows in the U.S. South. This is especially true for large office buildings which need much cooling.

Absolutely not !!!!!!!!   The high June 21 sun is the easiest to shade on south windows requiring only a small overhang which will not shade the low December 21 sun.  Such a small overhang appears to work exceedingly well but erroneously.

The logical goal is to shade windows while it is too hot outdoors.  That time of year is called the overheated period, and windows should be shaded during the whole overheated period.  Thus, a shading device should be designed to shade until the end of the overheated period, which in some U.S. climates is during September but never on June 21.

Similarly, shading devices should not block the winter sun during the whole underheated period.  No sun should be shaded until the end of the underheated period, which in some U.S. climates is March but never Dec. 21.