In a chilled water system, the chilled water circulates through a chilled water loop and through coils located in air handlers. Chilled water piping utilizes parallel piping systems with a two-pipe main distribution system arranged in a loop. The piping system is always black steel or copper. This excel sheet is for calculating piping loop head loss. The file format is excel Xls. Water pipe sizing excel calculator for HVAC chilled water systems is submitted below download it for free. The spreadsheet contains all formulas needed for the calculation of pipe sizing.