included with SunnyCad or enter your own components to customize the library data base. The libraries include all components needed to develop a complete solar project; locations, solar collectors, storage tanks, system pipes, boilers, heat pumps and electrical systems.

Climate data for irradiation and air temperature in hourly intervals for a period of one year is also included with SunnyCad. Weather data for more than 2100 locations is also available in the EnergyPlus weather format — 1042 locations in the United States, 71 locations in Canada, and more than 1000 locations in 100 other countries throughout the world. The weather data is arranged by World Meteorological Organization region and Country.

The weather data files are derived from up to 18 years of hourly weather data originally archived at the U. S. National Climatic Data Center. The weather data is supplemented by solar radiation estimated on an hourly basis from earth-sun geometry and hourly weather elements, particularly cloud amount information.

Any collector can be reproduced by entering parameters for the conversion ratio, specific heat capacity, heat flow coefficient and angle incident modifier. Evacuated tube collectors with or without reflectors can also be simulated. The designer can also set dimension and optical data. Complete data for more than 400 flat-plate and evacuated tube collectors is included with SunnyCad.

SunnyCad uses f-Chart calculations, widely accepted as the benchmark design method for solar systems and developed by the Solar Energy Laboratories at the University of Wisconsin. The f-chart method is used to estimate annual performance of active heating systems or the fraction of total heating load that will be supplied by solar energy systems.

Using the f-chart method SunnyCad calculates the solar project ratio referred to as the energy needs for producing hot water, giving indication of the number of solar collectors required, the storage capacity demand and total system efficiency. SunnyCad allows the designer to set the orientation of the collector type, slope and azimuth, allowing the designer to view several “what-if” scenarios to obtain maximum system placement and efficiency.

SunnyCad produces a monthly calculation of solar ratio of the installed system (%), energy provided by the solar system [Btu] and residual energy still deserved by the conventional heat source.

Detailed costing for collectors, gas and electrical energy can be entered in SunnyCad. Any loans, subsidies, discounts, depreciation and tax payments can also be entered for consideration in the final calculations. In addition to the capital value of a system, SunnyCad also determines the combustible saving and electricity production costs. The final result is a complete project business plan with a final return on investment calculation.

SunnyCad saves DWG files with the schematic layout of the system simulated (water heating only).
Comprehensive project reports in RTF format with detail of all formulas used for calculations and illustrations are included in the final report for presentation to the customer.

• System Input data including solar collectors, heat exchanger and storage tank, pipes, project location
• Solar radiation calculations
• Solar System efficiency
• Monthly calculated solar fraction
• Energy and other values in graph and table format
• Economic efficiency calculations