top of page
Search

High pressure shower head and water saving of the future

Updated: Sep 15, 2022


Looking for high-pressure shower heads that provide a cascade of water? You have come to the right place. What we are going to tell you might change what you think and help your search for your next perfect shower. So read on!



What consists of a good shower?


A high-pressure shower, or any good shower really, requires two major elements: high water flow through the shower head and high incoming water pressure. The water from a shower head feels good because the head provides a decent amount of water, good water coverage, and pressure, therefore, solely relying on pressure-boosting tricks on shower heads and ignoring house water pressure, and shower head flow rate will not yield the best results and there are often drawbacks like low coverage or temperature fluctuations. In fact, we would rank shower head pressure boosting as the least important among the three factors. We recommend anyone who wants to take good high-pressure showers at home to look for the highest flow rate shower head out there possible and check house water supply pressure, increase it if you can, or seek professional help.


Best way to save water and enjoy the high flow rate


Getting a high flow rate shower head does not necessarily mean increased water use, and vice versa if we factor in other variables like shower time. If you are worried about increasing water usage with higher flow rate showers, you can now save water differently with high-tech shower heads like Oasense. Oasense makes the shower head smarter, more enjoyable, and more efficient with its award-winning design and unique sensing technology. Don't settle for low-flow shower heads, as they don't save that much water in reality.


Watch Oasense Reva in Live action:





In this article, we will address carefully the following questions and hopefully provide a tangible solution for you for picking your next shower head. Here are the 5 key takeaways:




Why saving water in the shower is important

Climate change is upon us, whether we’d like to admit it or not, and as its impact starts to trickle down to people’s households, everyone is starting to feel the pinch. One of the most significant aspects of our lives that have been impacted is water. US water prices have almost doubled in the past decade, and roughly 20 to 70 percent of the U.S. is experiencing more recurrent dry weather conditions. What was previously abnormal is now becoming a regular occurrence. As the Chief editor of MIT Technology Review Matt Honan stated, most of us will first experience climate change through water, we will flood, burn or both, indicating that extreme drought or flooding would become a norm.


Showering uses on average 20% of all household usage and is the most water-consuming activity every day, and the average water usage for showers in the US is 20 gallons per person. For a normal family, you can easily use up to 1000 gallons of water in just showering alone each month. Moreover, shower water is usually heated water, which means that more energy is consumed during the shower versus using a garden hose, or flushing a toilet.


Feel like saving more water? We have some more sustainable water use tips here.



Where have all the high pressure (flow rate) showers gone?


To limit water usage during showering, a maximum cap of 2.5 gallon per minute (GPM) at 80 psi house water pressure for shower heads was introduced nationwide in 1992. This led to the initiation WaterSense Program from The Environmental Protection Agency (EPA) in 2006, which further defines shower head flow rates to 2.0GPM at 80 psi. WaterSense is a voluntary partnership program that labels water-efficient products and resources for helping you save water across all different products.


For modern shower heads, WaterSense not only ensures that the maximum flow rate is capped, it also regulates the percentage of flow rate decrease and takes into account house pressure drop so that you would still have a somewhat decent shower flow when your house water pressure isn’t that high.


Since it’s a voluntary program, states, counties, or cities can decide whether they want to partner with WaterSense to help residents and businesses to lower water consumption. This is usually based upon geo-location differences, requirements, and regulations that differ in different areas.


For example, where Oasense is located, in California, the shower heads that you can purchase will only have a maximum flow rate of 1.8 gallons per mins. It's not possible to buy a 2.5GPM shower head in home depot, nor purchase one on Amazon and ship it to California. There are places that have tighter regulations or looser flow rate. And whether WaterSense compliance is required. For example in the state of Colorado, showers sold need to be at 2.0 gpm rating at 80 psi and also need to be WaterSense certified, but in Arizona, the shower head needs to be at 2.0 gpm but WaterSense Certification is not required.


Here’s a table based on the latest regulation of shower heads we compiled, credits to Neoperl who makes good flow restrictors, or water savers, to help products to have good flows during low pressure for providing the data. You can also visit here to see how the shower head is tested by WaterSense. Please note that these plumbing codes are subject to change, and we compile the latest regulation on shower heads for you as of Jan. 2021, you can also read more about detailed WaterSesne testing and a full list of regulation here:





Why flow rate is more important than "pressure rating"


Low flow rate means low pressure, no flow, no pressure.


The most powerful shower head is the highest flow rate shower head possible with the best house pressure. Since 1992, and the water sense act, shower flow rate has decreased significantly; hence, the "pressure" of shower heads decreased as well.


One indirect evidence is if we use Google Trends to compare high-pressure shower head vs shower gpm over the last 10 years, the trend and popularity of search match perfectly. Why? Because once gallons per mins of showers started to go down, shower heads pressure goes down accordingly, hence consumers started to search for higher pressure shower heads.



The term pressure is not used very stringently as a scientific term when describing the shower experience. The water coming out of the nozzles have high speed, yet is very low in pressure. When these water droplets hit the skin, we feel the momentum transfer from water to a certain area of the skin, that is the strict term of "pressure" that we are feeling.


Furthermore, a good "pressure" shower might not necessarily equal to a good shower. It can be very pointy, and stingy and really lacks immersive soothing water coverage. We will try to explain why this is happening in layman's terms with just a little bit of fluid dynamics.


As previously explained, all the “pressure” we feel from the shower is the total force of the water droplets hitting our skin within a given time. Therefore, If we limit the total amount of water allowed into the shower head from the start (which is the definition of flow rate), the total possible flux of water, namely you only get that much water out per minute, the total "pressure" of the shower is limited. (in fact in some cases we are actually limiting the flow rate further in order to achieve high pressure.)


Although not in an ideal world, the water flow rate follows the continuity equation roughly:


Q (gallon per mins) = A1 (area of the standard half inch pipe)* V1 (water flow rate into the shower head) = Sigma A2 (area of nozzle orifice)* V2 (water flow rate out of the nozzle orifice)


Imagine a rubber garden hose is in our hand with water flowing, if we squeeze it, the total area (A2) becomes smaller and hence the flow rate (V2) becomes higher and we would see a somewhat higher pressure water stream. However, the total amount of water flowing out can only be less. And if the tap is half opened, no matter how we squeeze the hose, the pressure can not be increased too much.


Now consider the shower, the same principle applies, if the total gallons per min, Q here is limited, no matter how tiny the nozzle orifice becomes or whatever tricks that companies want their consumers to believe, say vortex shower head, mist shower heads, jet-like showers, the experience just can't be as good as before.


So when people asked, "How do I increase shower head pressure?" or "how to increase shower head flow?" or "is there a shower head that increases pressure?" the answer is the following: the best high pressure shower heads are high flow shower heads.


Shower pressure is dominated by flow rate. No matter how we change the nozzles, a 1.5 gpm shower head would have no comparison to a high flow, 2.5 gpm shower head, because the source of water is limited.



How to increase house water pressure for your shower


If you are in an area where the shower flow rate is restricted, try to see if you can increase your house pressure by adding a booster pump or swapping out the old pump. House water pressure could vary from 20 psi to 80 psi, and most houses have pressure around 50psi. Increasing the house water supply pressure would fundamentally improve the pressure situation compared to switching shower heads. This is the better answer to how to increase shower pressure.

Other things we recommend you to check would be filters, pipes, and precipitants on the filter, inside the shower head, or on the nozzles.



Paying the price of increasing water pressure for low flow compensation


From a thermal dynamic perspective, it is almost a blatant lie to say that there's a shower head that "increases" water pressure, they don't. These shower heads redistribute the water coverage and concentrate the water so you feel that the pressure is higher. There are no shower heads that work better for high-rise buildings, RVs, or low house water pressure. Take those same shower heads and fix or increase the water pressure, the shower experience would only be better in terms of pressure.


Now that we know that the high water pressure we are feeling is actually the total force of water that reaches our skin and that this is actually determined by water flow rate and the physics of the continuity equation, it would be easy for us to understand some other draw-backs from common high pressure yet water saving shower heads, because the energy doesn't increase, they are distributed, and therefore there are some short-comings.


Let's take these $2 dollar shower head that is cheaply made in China and marked up 20 times in store for example.


source: Alibaba , some one called this the fiji shower head for some reason



source: Alibaba


  1. Total water coverage has to be small and limited. In order to simulate a jet-like pressure, low-flow shower heads or even normal flow shower heads need to be designed with very focused water streams and concentrate them on very few nozzles so they burst water out as an artificial feeling of pressure increase. There are two reasons for this, first, restricting the orifice to boost water speed will also have some loss in water energy (imagine tons of water molecules squeezing out a tiny door). Each individual water stream could actually feel weaker because over-shrinking the orifice could actually decrease the flow rate. To compensate for that, concentrating all the nozzles on a small plate can create a feeling of higher pressure hitting one location on your skin. Secondly, since every twist, or extra travel distance of water in the shower head creates friction that makes the water loses its energy, best to avoid them at all cost to further preserve water momentum over these tiny nozzles. So yes in the small area you do feel a pressure increase because local speed increases, but the shower takes longer, and more body movement is needed to get a full rinse compared to a rainfall-type shower.

  2. Water gets cold very easily. Take the filtered shower head (top), a.k.a the Fiji shower head that uses laser drilled metal pin-holes or furthermore, some of the misting shower heads or shower systems, because the water droplets are so tiny, the total surface area of water contacting cold air increase a LOT, therefore water get cold very fast. When you move slightly away from the nozzles while showering, you would feel a sudden temperature drop. Even worse, you probably are asked and have to raise your water temperature setting at your heating tank or tankless heater temperature, which basically causes more energy and defeats the purpose of conservation. The misty-type shower heads that emerge recently have this exact problem.


Low flow shower heads is not your best water saving solution


One more common problem of low-flow shower heads that people face is prolonged showering due to a lower flow rate. (Koomey JG, Energy 20(7):627–635). It just takes that much water to dissolve the soap. If you decrease the water flow, then the shower has to become longer to get the same about of cleaning, and thus offset the savings.


Another interesting study pointed out by evolve technology and the Lawrence Berkeley national lab is that the lower the flow rate, the slower the cold water in the pipe will be pumped out, and more losses of energy would happen during the entire system., in this study, it is showed that if we limit shower flow rate to 1 gpm, it will waste up to 50% more of hot water during the warm-up phase.


Over-limiting shower flow rate can be devastating for the shower experience, not saving as much water because of the necessity of longer rinse, and more energy losses during warm-up phase.


So, what about water saving if low-flow shower heads are not great?



Future of high pressure showering and water saving, a smarter way





In designing our smart shower Reva, we thought that the best way to for people to enjoy high-pressure showering and save water is not to take the low-flow approach like some of our friends with misting sprays or extreme concentrate beams or vortexes that look cool but don't really do much. We wanted to deliver an old-school feeling, good flow, good coverage, and still be able to save water by concentrating all the water during rinsing and shutting off the extra flow when you don’t use it through our tech-integrated shower. We think that technology really benefits people by providing more than other smart showers like LED lights as a shower timer or shower shut-off timer, or just data streams over Bluetooth that you would get excited the first week about the data but soon forget about the app in your phone months later. We want to have an interactive water-saving experience that you can save without moving a finger and just enjoy a good shower.


We used a specially engineered embedded sensor. Very much like a sensor faucet that you are familiar with, but a lot more. Learn about our sensor technology that enables the highest efficiency shower head here.


When starting the tap, our temperature sensor would start sensing the water temperature, and when the temperature reaches your tap setting, yes we detect that as well using mathematical approaches to processing temperature data, the water flow turns into 10% of the maximum flow. That saves the behavioral waste of 10 percent instantly. You can be replying to texts, watching the news, checking emails or finishing that last drop of beer or coffee without worrying about the water, money, or energy that would usually just pour down the drain unused. '


Once you are ready to shower, just step into the flow, and our sensor will detect you and shower you with a full cascade of water. When you need to lather up, shampoo, or shave, just take a step back and water flow will reduce to 10% again. It’s giving you the key to saving water on your own terms, to be able to rinse as freely as you wish without having to compromise on experience with a typical low-flow showerhead. The technology needs to be able to design around user experience instead of limiting it. We think that this is what a true smart home product in 2022 should look like, addressing the issue, and keeping a good experience. We believe that Reva is the future of shower head design, and this is how we can enjoy and tackle water issues every day at home.


Learn more about Oasense Reva's experience design.











3,485 views

Recent Posts

See All

Comments


bottom of page