Plumbing
There are four factors to consider when analyzing the energy efficiency of your plumbing system. The amount of water that you use, your hot water production, how efficiently hot water can be carried to all the faucets in your home, and if there is any air leakage where the piping enters your home through the wall.
Efficient Water Usage
Many showerheads in existing homes use water at a rate of five to six gallons per minute. Current Energy recommends switching to a 2.5 Gallons Per Minute (GPM) showerhead. All sink aerators should be rated no higher than 2 GPM.
All toilets should be rated no higher than 1.6 Gallons Per Flush (GPF). It is recommended that toilets be purchased with a dual flush system. A dual flush (1.6 GPF / 0.9 GPF) performance option allows appropriate water usage. Depending on usage, a dual flush toilet can save hundreds of gallons of water per year.
Hot Water Production
A typical American home has a tank of hot water sitting either in the garage or attic, waiting for that water to be used. The forty or more gallons of water in the tank are heated 24 hours a day, whether you are using it or not.
Tankless hot water systems have the potential of reducing your energy usage up to 40%, depending on your household usage. Hot water is produced on demand rather than maintaining a full tank of hot water. The tankless system also provides hot water for as long as it is needed. A household can empty a tank hot water heater during usage, and then have to wait for it to refill and reheat the entire tank. Since the tankless unit heats the water on demand, hot water is available as long as it is needed. Also since there is no tank, there is also no need for a storage closet or the concern of a 40 or more gallon tank of water leaking all over the attic or floor of a home.
An alternative to a tankless system would be a timer to reduce the "on-time" of the water heater. A blanket around the water heater can also help maintain the tank’s heat, thereby saving energy. Keep the temperature set no higher than 120 degrees, or 140 degrees if a dishwasher is being used without a temperature booster.
Solar Water Heater
If you are installing a new water heater or currently have an electric water heater, a solar water heater could be a cost effective water heating solution. These systems are roof-mounted and tied into a traditional water tank to provide water heated by the sun.
Air Leakage
When thinking about comfort and efficiency in your home, it is important to consider any opening in the wall an area of potential air leakage. In the winter, hot air escapes from your attic or basement through the walls. In the summer, hot air flows into the conditioned space, causing your air conditioning to work harder. One overlooked area of air infiltration is where the plumbing enters your home through the walls. These areas should be well caulked, and checked periodically for air leakage.
Piping
In an older home, insulation around the piping may have worn away or fallen. Wrap or insulate all pipes carrying hot water through the home, to prevent heat loss.
Replacing an old showerhead with the 2.5 gallon-per-minute showerhead can reduce your water and energy consumption. Over the course of a ten minute shower, switching from a 5 gallon-per-minute to the 2.5 gallon-per-minute Speakman will save 25 gallons of water.
For example, the current rate for water in Dallas, assuming you use between 4,000 and 10,000 gallons per month, is $2.24 per 1000 gallons. That is a five cents savings each time you take a ten minute shower. If four people are taking approximately 300 showers per year in your home, you could save 30,000 gallons of water per year, or $67 per year in water costs alone.
