Who needs 80 gallons per minute?
The federal law, however well intentioned, didn’t anticipate the entrepreneurial wiles of plumbing manufacturers or the lust of some homeowners for hydraulic luxury. One leading manufacturer offers a $2700 “vertical spa set” with a large-diameter four-function showerhead, four body-spray nozzles, and a handheld shower, each rated at 2.5 gpm. Another offers a $4500 system with a half-dozen showerheads and body-spray nozzles, each of which meets the federal 2.5-gpm standard.
At least one European manufacturer suggests that what it’s selling isn’t a shower at all. The company’s brochure states that for the United States and Canada, the product “is not designed for or intended to be used in any circumstance as a plumbing device, shower system, or for use in violation of any applicable law.” The fact that a naked woman is shown being drenched by a ceilingmounted rain panel must be purely coincidental.
Manufacturers of such systems warn of overwhelming a home’s infrastructure. With multiple valves, some custom shower systems can deliver 32 gallons of water per minute—enough to fill a standard 5-ft. bathtub every minute. A leading plumbing-valve manufacturer recommends at least a 100-gallon water heater. Manufacturers recommend dedicated 3⁄4-in. or even 1-in. supply lines from the water heater. Draining these systems adequately requires two 2-in. floor drains or one 3-in. drain. In rural areas, a home’s wellwater supply may not keep up with the flow of custom shower systems, and the septic tank may not be able to handle the effluent.
A number of systems on the market, including one that delivers up to 80 gpm, use a recirculating pump with an integral heater. The reason for this is that a reasonably sized water heater simply can’t keep up with that level of water flow. For those needing nearly three bathtubs’ worth of water per minute, the recirculating pump is probably a good thing, using a lot less water and energy than a once-through system.