Solar Water Heating Calculation for Built Up System

The Title 24 Solar Water Heating Calculator is designed to calculate solar thermal water heating contributions for built up solar systems. The solar fraction generated is based on compliance with the 2013 Title 24 Building Energy Efficiency Standards and should not be used for any other purpose.

Download the zip file containing the "T24SC.exe" program file. Unzip the file and run the program. If you have questions about the program contact the Energy Hotline at (916) 654-5106 or send an e-mail to

This program uses ratings from the Solar Rating and Certification Corporation for solar thermal collectors using the OG-100 test method. If your system has an OG-300 rating use the calculation approach provided in the Residential Compliance manual.

This software is only available for Windows-based computers.

Download the file containing the calculator. Updated .