Well, I can’t get to the secret without an introduction. It is all about low flow water fixtures.
While we were getting ready to sign up for the Chicago Green Homes Program, we decided that one of our Green Permit Menu Items is exceptional water management.
This menu item requires compliance with the USGBC LEED credit WEc 3.1. I quote from the credit:
Meet one or more of the following requirements by installing high efficiency (low-flow) fixtures of fittings. […]
- The average flow rate for all lavatory faucets must be less or equal to 2.0 gpm.
- The average flow rate for all showers must be less or equal to 2.0 gpm per stall.
- The average flow rate for all toilets must be less or equal to 1.3 gpf OR
- Toilets must be dual flush and meet the requirements of ASME A112.19.14 OR
- Toilets must meet the U.S. EPA WaterSense specification and be certified and labeled accordingly.
These requirements are actually rather generous. We have to do much better than this, which is mandated though the plumbing code variance we received. That variance released us from upgrading our existing one inch water service line to one and a half inch, but we need to meet the following:
- 0.5 gpm lavatory faucets
- 1.5 gpm kitchen faucets
- 1.5 gpm shower heads
- 1.28/0.8 gpf dual flush water closet (averaging 0.9 gpf)
These mandates allow us to meet and exceed the LEED credit WEc 3.2, which is a notch more stringent than the above mentioned WEc 3.1. Again, I quote from the credit:
Meet one or more of the following requirements by installing very high efficiency fixtures or fittings. […]
- The average flow rate for all lavatories must be less or equal to 1.5 gpm OR
- Lavatory faucets must meet the U.S. EPA WaterSense specification and be certified and labeled accordingly.
- The average flow rate for all showers must be less or equal to 1.75 gpm per stall.
- The average flow rate for all toilets must be less or equal to 1.1 gpf
See also: LEED for Homes Rating System
Let’s focus on the showers, which can’t exceed 1.5 gpm. It’s not easy to find a shower head that meets this requirement and feels comfortable – meaning that it doesn’t just give you a pathetic trickle of water.
I eventually found a product that could work. It’s manufactured by Oxygenics and is called the ‘BodySpa SkinCare Showerhead’. (A shorter, snappier product name would do much better, don’t you think?).
I say ‘could work’ because the water output varies with the water pressure. This shower head would meet the 1.5 gpm requirement if the pressure won’t exceed 37 psi.
Could I swing this? To find out, I purchased the showerhead to try it out at our rental place, the HUB.
I was instantly impressed by the very nice and forceful stream of water, so much so that I did not want to believe it would be as little as 1.5 gpm. Well, it was pretty simple to find out. I ran a test with a stopwatch and bucket, and lo and behold, the output hovered around 1.5 gpm, which also confirmed that water pressure is a critical variable.
To get this to work, to get to my 1.5 gpm output, I need to control the variable, the water pressure. And we finally arrived at the secret of the shower riser!
I called Mariusz who stopped by with an adjustable pressure reducing valve. He installed the valve in the shower riser, shortly after the hot and cold water mixing valves. I set the dial to 30 psi, which should firmly put me in the 1.5 gpm range.
Another quick test with my stopwatch and bucket confirmed that everything is performing as it should.
The pressure reducing valve is a somewhat cumbersome and expensive solution. The valve is not cheap! There may be other simpler options that we could try.
Last November, on the GreenBuild tradeshow floor, I came across a new product from Niagara that has a built-in pressure compensator. That would eliminate the need for the pressure reducing valve and make the solution a whole lot simpler.
I don’t know if that showerhead will work as well as the current one, or if the pressure compensation will perform as promised. There is only one way to find out. I ordered a sample and will give it a try. This may be the solution for the 1st and 2nd floor bathrooms.