What is total dynamic head (TDH)?
Head is measured in feet/meters or psi and it is a term for the distance that a pump has to push the water from your source to your tank. It may seem odd to be able to list head in terms of pressure or distance, but keep in mind that a column of water 2.31′ tall produces 1 psi at the bottom of that column so there is a correlation between distance and pressure. The greater the vertical distance is in between the water source and the tank, the harder the pump has to work to get the water there. Static head is the simple measurement from the surface of the water (when the pump is not running) to the tank. Dynamic head takes into account the amount the water level in the well drops when the pump is running plus the friction loss in the discharge pipe run. Total Dynamic Head is the sum of the static head and dynamic head.
