It is a unit of measure used to evaluate the demand that a particular plumbing fixture, or group of fixtures, will put on the plumbing system. It is used in conjunction with other factors, and there are fixture units assigned for both water supply and drainage. The fixture unit rating takes into account the likely volume of flow, average duration of use, and expected frequency of use. Here’s how the Residential Edition of the Florida Building Code (FBC) and the International Residential Code (IRC) define them:
A full bathroom, for example, is rated at 3.6 w.s.f.u. (water supply fixture units), while a clothes washer is given a 1.4. Only fixtures that dispense water have fixture unit ratings so, although fixture units are used to calculate the size pipe serving a water heater, the water heater itself is not assigned a fixture unit value.
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Here’s links to a collection of our other blog posts about PLUMBING:
• How can I protect my pipes to keep them from bursting during a hard winter freeze in North Florida?
• Why is there sand in the bottom of my toilet tank?
• What causes a gurgling sound when a bathtub or sink drains?
• Are drop-in toilet bowl cleaner tablets safe?
• What can I add to my septic tank to help it work better?
• What are the code requirements for layout of drain piping under sinks?
• Why is there mold inside my toilet tank?
• What are the pros and cons of a wall-mounted toilet?
• Which plumbing fixtures require water shut off valves in a home?
• How can I tell if a house is connected to a septic tank system or sewer?
• Are plastic pipes (PVC, CPVC, and PEX) safe for drinking water?
• Why is a backflow preventer required on lawn sprinkler systems?
• How can I locate my septic tank?
• Is a hot water faucet handle required to be on the left?
• Can you live in a house while the plumbing is being replaced?
• Why is the European-style bottle trap not approved by the plumbing codes in the U.S.?
• Why can't PVC be used for water pipe inside a house?
• What are the common problems to look for when the plumbing has been replaced in a house?
• What's that powdery crust on the pipe connections at the water heater?
• How can I tell what type of plumbing pipe I have?
• What causes low water pressure in a house?
• Should I call a plumber or septic tank contractor when my septic tank backs up into the house?
• How do I get rid of the sewer gas smell in my house?
• What are the pipes on my roof?
• Should I wrap the water heater with an insulation blanket?
• My water bill went way up last month. How do I look for a leak?
• Why does the water have a rotten-egg smell in some empty houses?
• What is an "S-Trap" under my sink? Why is it a problem?
• Where is the septic tank? Are you going to inspect it?
• What does polybutylene pipe look like? Why is it a problem?
• Which water pipes are an insurance problem and possibly uninsurable?
• Does a home inspector check the plumbing under the floor slab?
• Is it alright to disconnect the washing machine drain from the septic tank and divert it to the ground in the yard?
Visit our PLUMBING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.