Wednesday, January 14, 2009

Define Your Shade – Water Efficiency

Today we are looking at Water Efficiency. By definition, water efficiency is accomplished by completing typical tasks using the least amount of water possible. As with energy efficiency, the idea is not to completely change behavior, but to change the mode in which water is delivered.

In order to reduce the amount of water used, many companies are developing new, viable products that accomplish the same tasks using much less water than their predecessors. Some of these products include:

Dual Flush Toilets
– Unlike a typical toilet, Dual flush units have an innovative system that allows for two different amounts of water based on need. The first flush typically delivers about .8 gallons of water, saving about 1 gallon per flush. The second flush delivers 1.6 gallons, the normal amount of water a typical toilet delivers. In a given day, a family of 4 can save about 20 gallons of water, depending on usage. (Additional Cost ~$70-120 depending on manufacturer and wholesaler)

Low-flow Shower head
– Delivering about 1.75 gallons per minute, technology has dramatically improved over the past few years to deliver the water in such a way as to not feel like you are stepping into mist, as opposed to a shower. Water savings is about 30% over a conventional unit, saving about 20 gallons of water for a family of 4. (Additional Cost ~$20/shower)

Low-Flow Faucets
– Faucets typically flow at about 2.2 gallons per minute. Their slim sister reduces flow to about 1.5 gallons per minute. Side-by-side comparisons show little difference when used by consumers and industry professionals. Water savings will vary greatly depending on your typical usage, for our purposes and to complete the example above, we will use about 10 gallons for our sample family per day. (Some faucet manufacturer include this feature at no cost beginning this year, otherwise about $2/faucet)

Innovative Options
– The list so far are items that will not really change the way in which you use these features in your home. Other options are available, however, to be effective, you must change habits and behaviors. The following is a short list of optional features:

  • Recirculating Pump – delivers hot water immediately eliminating the need to run water for it warm up.
  • Composting Toilets – Waterless toilet system that converts human waste into usable compost/soil.
  • Low-water Irrigation Systems – System that use rain collection systems, non-spray (drip) systems, or special timers and moisture sensors.
  • Specialty Faucets – Motion sensors, shut-off valve or pedal-activated faucets.

In summary, if you implement only the first three items, you average monthly savings for a family of four will be about 1500 gallons of water. Remember this is without changing any behaviors or standards of living.

Next week is the International Builder Show in Las Vegas, NV. During the show, many products will be demonstrated to show the newest technologies to save water and reduce usage. Stay tuned for future product reviews and options to save water.


  1. I've been told that pipe capacity can impair the effectiveness of low flow toilets. This was an issue with a late 80s MF rehab project; the pipes were too large for the volume of water. We calibrated the toilet machinery and achieved a 30% reduction in water use.

    Is this something you've encountered?

  2. Great Question. In my experience, there are no issues in single family construction. The situation referenced above typically occurs because solid waste material needs more water to move through the pipes. With a dual flush, the same amount of water in a standard toilet is deployed to remove solid waste from the bowl. The low flow flush only plays a role when no solid waste or only a minimal amount of paper is present in the bowl.

    The other thing to check on any installation is the angle of the pipe discharging the waste from the home. Too little or too much can have adverse affects on the performance of any toilet or drain.

  3. For those of us who are not in the building industry, this blog is a wonderful education so when we actually buy a home or build, we can know what is available, what to look for, what to request and to be careful of so that we can
    contribute to the "go green" campaign and save money as well. I appreciate what is going on here. Thank you from a consumer