Water Supply and Drainage Fixture Units Calculator - WSFU & DFU

Calculation of water supply fixture units and drainage fixture units is important for plumbing design engineers as this will lead to determining the equivalent flow in gpm running through water pipe or drainage pipe. Download this excel sheet and it will help you calculate both WSFU and DFU.

Download also: Hot and Cold Water Supply Calculation Spreadsheet and Water Demand Calculations Excel Sheet - XLS Calculator

Water Supply and Drainage Fixture Units Calculator

Download Water Supply and Drainage Fixture Units Calculator - WSFU & DFU Excel Sheet

How to calculate the water supply and drainage fixture units?

When sizing water supply piping according to the International Plumbing Code (IPC), several factors need to be considered, including the fixture unit count, pipe material, and pipe length. Here's a general guideline for sizing water supply piping:

1. Determine Fixture Unit Count: 

Determine the total fixture unit count for each plumbing fixture connected to the water supply system. Fixture units (FU) represent the water demand of various fixtures. The IPC provides a table with fixture unit values for different fixtures and their usage patterns.

2. Calculate Total Demand: 

Add up the fixture unit counts for all the fixtures in the system to determine the total demand in fixture units (DFU). This represents the maximum water demand for the system.

3. Determine Equivalent Fixture Units (EFU): 

Convert the fixture unit count (DFU) into equivalent fixture units (EFU) based on the fixture type and usage pattern. The IPC provides conversion factors for different types of fixtures.