Solargy Inc

Solargy offers a full range of Solar Studies

Solargy Inc. has been performing a variety of Solar studies for many years. We have been serving the needs of architects, engineers, contractors, and homeowners for more than a quarter century.

Solar Studies
• Shade & Shadow Studies
• Solar Access Reports
• Active and Passive Design
• Sundials

If you would to know more about these Solar studies, please read the information below.

Shade & Shadow Studies

There may be times when architects, developers and owners are interested in seeing the shading impact of their proposed structures on the structures themselves or adjacent land and buildings or vice-versa. It is very easy to make a preliminary shading analysis while the design is in the formative stages, including "what if" scenarios.
Solargy, Inc. will be happy to provide the analysis at a modest price.

Solar Access Reports

State of California

The State of California has mandated that before a planning department can approve a tract of land for new structures, a "Solar Report" a.k.a. "Solar Feasibility Report" must be submitted and approved. The original intent of this mandate was to get the developers thinking about such things as orientation of buildings for optimum passive operation, planting of trees which will help shade buildings at the appropriate times of year, efficient heating and cooling equipment. Unfortunately, the mandate has had little impact, simply because by the time the developer becomes aware of its existence, the project has often already been designed. Fortunately, the report itself is not required to mandate the use of any active or passive devices, and thus becomes just another piece of paperwork for the developer to get out of the way.
Solargy, Inc. will be happy to prepare the required report for a modest fee.

Local Municipalities

In the Seventies there was somewhat of a hubbub over "Solar Rights", seeing as the reigning propaganda at that time was that solar energy would save the world from the worsening energy crisis. Nevertheless, in California since that time, I have seen almost nothing regarding that issue. In Southern California, the only place where I have seen an ordinance addressing solar rights is in Westwood.
Solargy will be happy to prepare any report a local authority may require regarding solar access rights, including the appropriate shading analyses.

Active and Passive Design

Active solar systems are those, which rely on pumps, motorized valves and or dampers, in order to collect energy from the sun. The classic example of this system is the collectors on the roof and the pump and storage tank in the garage; the pump moves water to the collector where it picks up heat and then goes on to the storage tank. Another example is the solar pool heating system that relies on the filter pump (or any other pump) to move water through solar collectors.
Nowadays, most solar systems are "designed" by the installing contractor. The reason for this is that there are numerous legitimate recipes and rules of thumb that have evolved over the years to make it less design and more "cookbook".
Nevertheless, for larger systems or ones with a new wrinkle, Solargy, Inc. will be happy to provide design services at a modest fee.
Passive solar systems are those, which have no reliance (or minimal) on pumps, fans, motorized valves and or dampers, in order to collect energy from the sun. Passive design, in common parlance, is applied to the following two situations.
Passive Devices
An example of this would be an integral collector/hot water storage tank. As the water heats up it rises to the top of the tank where it is drawn off when hot water is called for; no pumps are required. A pool cover, even if motorized, would be considered a passive device. A blind or shade would be considered a passive device.
Passive Architecture
The classic case of passive design here would be the south-facing window with appropriately sized overhang and internal thermal mass. By proper selection of the window, mass and overhang, it is theoretically possible to get significant free heating in winter. Unfortunately, in California, outdoor temperature swings make this approach problematic; overheating, lack of control, etc. Solargy, Inc. feels that, in general, passive design in the last used sense does not make sense for probably any area in the United States. While this may seem heretical, let me elaborate. The last 20 years has seen the emergence of a wide variety of insulation, infiltration controls, energy efficient windows and high efficiency heating and cooling devices. By proper selection of the aforementioned passive devices, including overhangs, blinds etc., and one can reduce energy use to heretofore unheard of levels. Obviously, judicious use of mass would be helpful.
Having said this, Solargy, Inc. will provide passive energy analyses for passive architecture in the classic sense for a modest fee.


Sundial design and construction is called gnomonics or sciatherics. The first sundial that can be traced is credited to Berossus (c. 300 B.C.), but undoubtedly they were around long before that.

Types of Sundials

A. Where the edge making the shadow (called the style or gnomon) is parallel to the north celestial pole (parallel to the earth’s axis) there are nine classes, named according to the position of the surface on which the shadow falls or the position thereof.
• Horizontal dials
• Reclining dials
• Vertical dials facing north or south
• Vertical declining dials.
• Direct east and west vertical dials
• Polar dials
• Equatorial and Armillary dials
• Spherical dials
• Cross and star dials

B. The style does not point to the celestial pole
• Analemmatic dial
• Pillar dial
• Portable card dial

C. Miscellaneous Dials.
1. Wheatstone’s solar chronometer; one could argue that this is not a sundial in the normal sense of the word but it is particularly fascinating to me. It makes use of the fact that light from the sky is polarized and this polarization varies throughout the day. The device makes use of a Nicol’s prism and a plate of Iceland spar. Its main advantages are that it can be directed to the a part of the sky and so can be used in a confined space, it can tell time prior to sunrise and after sunset!!, and it works if the sky is cloudy!
2. There are numerous "modern" designs, e.g. a sundial where the time appears in numerical form, information about which and others (new and old) may be obtained from such sources as Bulletin of The British Sundial Society and The Compendium of The North American Sundial Society. Solargy, Inc. (Tom Rotchford) is a member of both organizations.
Why do sundials not keep accurate time? The main reason is that the rotational axis of the earth is tilted with respect to the plane of the earth’s orbit around the sun and that the speed of the earth in its elliptical orbit varies throughout the year. That change in speed amounts to a change in the angular velocity about the sun. With respect to the distant stars, this change is added to the angular velocity of the earth about its own axis (360 degrees/24 hours). Working out formulas for the effect of all of this is not as straightforward as one might imagine (a closed form solution does not exist) but tables or computer programs are available to compute the change. Sundials run as much as 16.3 minutes fast and 14.3 minutes slow. Many sundials are designed without compensation for this effect while others have clever schemes to account for it.

If you would like consultation or design services in the design of a your small or building size sundial, give us a call or email.
Sundials, Frank W. Cousins, John Baker, London, 1969.