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NSHP Program

Solar Fraction Calculator for Built-Up Systems Using SRCC Certified Solar Collector

photo of new solar home bi-pv roof

California F-Chart is a user-friendly version of the F-chart program that has been designed to calculate the solar fraction for built-up solar water heating systems in California.

Required Information

To use the California F-Chart program, the following information is required. Obtain the information from the building plan set or from the solar system designer's specifications. This information must be entered into the California F-Chart software.

Select a SRCC Certified Collector

California F-Chart has a drop-down menu listing all collectors currently certified by SRCC. When you select a collector from the drop-down menu, the program automatically uses the SRCC certified rating values for the Collector square footage, Collector Y-Intercept, and Collector Slope. All of the other information necessary for the calculation is accounted for automatically in the California F-Chart software.

Run California F-Chart

California F-Chart is a self-installing EXE file. It will install into the directory C:\CEC_F-Chart. Once installed, run the program. After the required information is entered, hit the calculate button. The program will generate a form, CF-Sr-100, that reports the solar fraction. Print the completed form for submittal with the SRCC data sheet and the CF-1R.

The Solar Fraction determined by California F-Chart is entered as an input to a Commission-approved building energy compliance computer program to determine the contribution of the solar water heating system towards compliance with the Standards or meeting the New Solar Homes Partnership energy efficiency requirement or qualifying for other incentive programs.

If there are any problems, repeat the installation process. If this does not work or you have questions about the program contact the Energy Hotline at (916) 654-5106, toll free at (800) 772-3300 or send an e-mail to Please do not contact the webmaster for assistance.

CEC_F-Chart Calculator Page