Infrared Training Center

Wednesday, March 3, 2010

ShowIR PowIR

by Kenneth R Brown, MD

After shopping for a new and hopefully attractive shower head that would meet federal standards for low flow, we chose a very nice name brand model and had it installed. Unfortunately, I had it mounted too high for convenience for my wife, so I promised that I will always return the rotating head which has three optional positions, to the fine spray position that she prefers. I tend to use the pulsing position or the "straight through" position, either of which I had always felt were warmer than the fine spray. While in the beginning my issue was the saving of water, when the plumber was at the house the next time, I explained that the water at 2 feet from the fine spray shower-head was cooler than when from the others. He vigorously defended his position. While I explained to the plumber that I could not vouch that this phenomenon was really as consistent as the inverse square law for light, it sure seemed like a good analogy. Furthermore didn't everyone know that as the water falls in smaller droplets it will get cooler faster that if in a single stream?
Enter the FLIR 300B- I took the plumber to the computer and showed him the three shots of the shower head positions at full pressure and max temperature and he was finally convinced, see them below.
Figure 1
Figure 2
Figure 3
So, back to the thermograms and measurements
Figure 1 is the fine spray, which runs coldest at given setting, and allows 1.475 gpm. Figure 2 is the 'the straight through"' setting and allows 2.12 gpm. Figure 3 is the pulsating shower and allows 3.3gpm. An early model water saver head in the upstairs bath puts out 1.32 gpm, and by the time it reaches my fingertips is it too cool for me to tolerate.
"Install Low-Flow Fixtures
Federal regulations mandate that new showerhead flow rates can't exceed more than 2.5 gallons per minute (gpm) at a water pressure of 80 pounds per square inch (psi). New faucet flow rates can't exceed 2.5 gpm at 80 psi or 2.2 gpm at 60 psi. You can purchase some quality, low-flow fixtures for around $10 to $20 a piece and achieve water savings of 25%–60%. "
Conclusions
Bottom line for me is: For a good shower with low flow spray, you need to jack up the temperature to one that scald some people using other flow rates. But if you do not take a long shower, you save a lot of hot water using the spray. If you like the pulsating backrub, it will cost you >2 times as much hot water as the spray.
Finally - the way to save heated water energy is to take an army-navy shower, keep the temperature <= 120 Deg.F at the tap; finally, when showering, let the water remain in the tub, open the bathroom doors and the heat will not all be wasted, but rather it helps to warm and humidify the house!
Ken earns 8 ITC certification renewal credits for this article.
Do you have an opinion on water saving shower heads? Do they really save water (if you take a longer shower to rinse well)? Do they really save energy (higher water temperature and longer shower)? Sound off below. - Editor

1 comment:

  1. Imagine an ideal low-flow shower head... maybe one that would send out short, intermittent bursts of water through larger nozzle size.

    You could still get the warmth and pressure, while decreasing to flow.

    ReplyDelete