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How to Calculate the Size of a Solar Hot Water Thermal Storage Tank

Solar water-heating systems are increasing in popularity as energy prices continue to rise. These systems are less expensive than systems that produce electricity from sunlight, and have a faster return on investment. Since water heaters are one of the biggest energy-consumers in the home, installing a solar system makes a lot of economic sense. Installing a system that is too small or too large will have a negative impact on the efficiency of the system. Proper thermal storage sizing depends on several factors, but is not difficult to calculate.

Things You'll Need

  • Tape measure
  • Notepad
  • Pencil
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Instructions

    • 1

      Measure the solar collectors to determine their size in square feet. Multiply the length of each collector by the width and add the products together to determine the combined square footage. Write down the total square footage of all collectors combined.

    • 2

      Multiply the total combined square footage by 1.5 for cooler climates. Write down the product. Size the tank as close as is practicable to the product.

    • 3

      Multiply the total combined square footage by 2 for warmer climates. Install a tank that is as close as is practicable to the product.