Sun Exposure
This section is a brief study of sun exposure to aid the positioning of the main house, allowing optimum use of sun exposure for front window viewing, rooftop solar collection, landscape, etc.
Being this far north in the northern hemisphere of course means the sun is always in the southern sky. This figure shows the general location and yellow arrows indicate the sun angles, numbering right to left in 24-hour format, solar hours ( not clock hours ). Click the figure in the popup for a closer look.
The mountains to the north and east of the location are ~ 2,000-3,000 ft high and approximately 4 miles or more away. The surrounding treetops are less than a half-mile away in the southerly direction and immediately adjacent to the property line to the west. The detail of these obstructions is displayed below as a “shadow profile”, which becomes an integral part of the analysis.
click to enlarge
Collecting the data for such a chart is made infinitely easier with a compass equipped with a movable dial to account for magnetic declination and a direct viewing clinometer for determining the angles of elevation of sun angle obstructions (trees, etc.). The IP65 Hiking Compass is such a device, available on Amazon for under $20.
There are several websites that help with calculating sun angles, including the following.
- The NOAA Solar Position Calculator is not particularly useful but the NOAA Solar Calculator creates a Sunrise/Sunset table in pdf format, which can easily be converted to Excel format. This Website, unlike some of the others, being government-funded, can be relied upon to be available in the future.
- There is a simple SunAngleCalculator, which
- Has a relative site elevation input feature (one value – not from multiple angles)
- Includes a calculated magnetic declination value
- Another page on the same Website has a SunPosition calculator for geeks who want all the data in spreadsheet form, including every variable imaginable.
- The University of Oregon Solar Radiation Monitoring Laboratory offers printable charts,
- Polar or Cartesian display formats
- Adjustment of some plotting parameters, including limited labeling
- PDF or PNG output file formats
- The SOCIETY OF BUILDING SCIENCE EDUCATORS site
- Is rather outdated in terms of technology
- Offers a kit with an overlay for paper/pencil analysis
- Has a good description of magnetic declination or magnetic variation
- Describes the importance of this kind of information to the building industry
- SunEarthTools seems to be the most useful site, albeit difficult to understand.
- Supports 7 digit decimal format points
- Enables custom shadow profiles
The only one I have found
There are probably others, but I didn’t do an exhaustive search - Even provides a script to embed in your own Website
- Takes a while to understand – probably translated from Hindi
- Lots of advertising but it is FREE
For properties like this one, the custom shadow profile is an essential part of the result. For that reason, I chose the SunEarthTools site for this analysis, the results of which are shown below.
