According to federal regulations, all kitchen and bathroom faucets should have a maximum flow rate of 2.2 gallons per minute (gpm) at 60 psi (pounds per square inch) of pressure; in California and Georgia, maximum flow rates are further restricted to 2.0 gpm (California will eventually be restricted to 1.8 gpm).
The average flow rate for faucets is between 1.0 gpm and 2.2 gpm. In the US, the maximum flow rate for kitchen and bathroom faucets is 2.2 gpm at 60 psi. In more environmentally regulated areas, the maximum flow rates are further restricted.
Bathroom Faucets
As a general guideline, the faucet flow rate in the bathroom should be 1.5 GPM or less. This is the maximum flow rate established by the EPA's WaterSense program, and generally speaking, that's more than enough water for a bathroom faucet.
GPM means Gallons Per Minute. Also known as "flow rate", GPM is a measure of how many gallons of water flow out of your shower head each minute. Since 1992, a maximum of 2.5 GPM is the federally mandated flow rate for new shower heads. This means no more than 2.5 gallons of water should flow out each minute.
Sink Faucet
Since 1994, faucet standards have been between 2.2 gpm and 2.5 gpm. Aerators are the nozzles with a screen on them that the water flows out of on your sink faucet.
Please keep in mind that all new faucets since 1994 are restricted to conserve water per EPA code mandates. Older faucets had no restrictions. Beyond intentional flow restriction, new installations can sometimes have reduced flow if the lines are not flushed prior to installation of aerators or shower heads.
Unfortunately, there is no firm definition of low-flow, but it's generally accepted that anything using 1.5 gallons per minute (gpm) or less is considered “ultra low flow,” while anything using 2.5 gallons per minute to 1.5 gallons per minute is considered “low flow.” Nowadays, thanks to standards set by the government ...
Due to National Conservation Laws, Moen manufactures all Kitchen sink faucets with or without a side spray at a 2.0 gallons per minute and all Pullout/Pulldown sink faucets at approximately 1.5 gallons per minute.
Efficient shower heads use at least 1.5gpm. Taking the same amount of time in the shower uses only 15 gallons of water. The water savings amount up to 65 gallons of water!
Low-flow faucets
In the United States, conventional kitchen and bathroom faucets must not use more than 2.2 gpm. Faucets that meet energy efficiency standards for WaterSense mustn't use more than 1.5 gpm, a 32% decrease in flow rate over the federal requirement.
Standard shower heads use 2.5 gpm, but to earn the WaterSense label, a product must use no more than 2 gpm and still meet strict performance requirements.
Before choosing bathroom faucets, you'll need to consider a few factors, such as whether you're using an existing sink or buying a new one, where are the faucet opening. You'll also need to consider which features you want, as well as how much faucet your budget will allow.
Aerator Blocked or Stopped Up
If the aerator is blocked with dirt, debris or plastic shavings it will not produce a high rate of water flow. This is common in some faucets recently installed, especially if the aerator screen is exposed to debris before threading it onto the spout.
Low flow faucets use technology like aerators to limit flow by mixing air into the water stream. Toilets use gravity or pressure assistance to achieve similar results. Reducing your water use then saves you money with a reduced bill. You'll also save on your energy bill because you'll use less hot water.
A 2.5 gpm shower head will have a better pressure and shower experience than a 1.5 gpm shower head. A 1.8 gpm shower head would have a better pressure and shower experience than a 1.0 gpm shower head. Another drawback of low flow shower heads boosting the pressure is the temperature instability.
Areas indicating a maximum flow rate of 4.0 gallons per minute or more are generally satisfactory for running 2 showers at a time with standard showerheads.
Differentiating Between Low Flow And High Flow Shower Heads
If you're looking for the most pressure, go for the 2.5 GPM Flow Rate, unless you are restricted because you reside in California, Colorado or New York. Again, this has been the Maximum Flow Rate since 1992. The step down from there in Flow Rate is 2.0 GPM.
Low Flow Faucets - Switching to a low-flow faucet that uses 1.5 gallons per minute can reduce your sink's water flow by about 30% or more. Low Flow Toilets - standard toilets use 1.6 gallons per flush, compared to the 1.28 gallons used by low-flow toilet fixtures.
The savings with a low-flow faucet
The average faucet runs 2.2 gallons per minute, while low-flow models run 1.5 gallons per minute. According to the U.S. Environmental Protection Agency's WaterSense program, a low-flow faucet that reduces water flow about 30% can save a home 700 gallons of water a year.
If your showerhead is labeled 2.5 GPM or less, you have a low-flow showerhead. Any showerhead labeled 2.6 GPM or above is a high-flow showerhead. If your showerhead doesn't have a label, try this trick to determine the flow rate. Place a bucket or container with a 1-gallon marker under the showerhead.
After all, it needs certain amount of water to remove the soap, that is physic. Studies have shown that 1.8 gpm is the minimum flow rate to have a good enjoyable rinsing, so the common 1.75 gpm models, is somewhat good enough for a decent shower. To save water further and still have a full enjoyable rinsing experience.
The term “low flow” refers to fixtures that use a lesser amount of water to accomplish everyday activities, such as showering, washing your hands, or flushing the toilet. In some cases, low-flow fixtures can reduce water usage by as much as 60 percent over standard fixtures.