Maximum allowable pipe length table C404.5.1

[Carlos Gutierrez]

Hi. I am new in the forum. can somebody explain how to interpret table C404.5.1 from Florida Building Code 2017 Energy conservation? I am having trouble understanding how far a plumbing fixture can be from the water heater.

Thanks.

 

[FishScreener]

The intent is to reduce the flow time before the hot water gets there to two gallons or less. This is part of why in “efficient” houses you install manifold pex systems, and use 3/8 to flow to the hot side of fixtures.

So, you can run 50-ft of 3/8-inch, or 43-ft of 1/2-inch.

If your designing Public buildings you need the heater in an adjacent mechanical room, or a return circulation loop. To stay at the five foot maximum.

 

[Carlos Gutierrez]

Thanks Fishscreener, but looking at the table, it says that for a public lavatory in 1/2” I just can run 2 ft. Is that correct?. If so I would need a loop for every single lavatory I have.

 

[Diehard]

The way I read it, you have a choice of a small(Point-of-use) electric water heater under the sink or a small recirc system for a number of sinks in the same general area, fed by a slightly larger Point of use water heater.

Best design based on where and how many LAV's you have and how best to satisfy the requirements looking at the big picture.

For example, a factory with many wash sinks and larger hot water demands vs. small commercial space with a few LAV's. Existing or proposed utility space layouts, etc.

 

[carlosgt1]

Another issue I see in the table is that they separate public lavatories from “other fixtures” I guess a public lavatory is the one in a public bathroom, but what is a have several exam rooms with sinks, would those be considered public lavatories?