SAVE WATER AND SAVE ENERGY


Commercial and public buildings consume significant amounts of water for both indoor and outdoor applications.  By taking steps to reduce water consumption, building owners can save money by reducing water bills and also realize substantial energy savings from reduced hot water requirements.  Through moderate efficiency efforts, commercial and public building owners can reduce water consumption and associated energy expenditures by up to 40%.  The answers to the questions below will help you find water-efficient technologies and will provide some recommendations for reducing indoor and outdoor water use at your facility, along with some information that you may want to consider if replacing your water heating system.

Water Heating and Conservation FAQ

  1. What are some basic suggestions for reducing water consumption in my facility?
  2. How can I reduce outdoor water use at my facility?
  3. Where can I find more details about best management practices for water efficiency?
  4. What should I consider when retrofitting my water heating system?
  5. Are there any incentives or rebates available to help offset the costs of my water system upgrades?

1. What are some basic suggestions for reducing water consumption in my facility?

  • Perform a leak survey of your facility by measuring the water meter after work hours and again in the morning to see if water was consumed when building occupants were not present.
  • Replace older toilets and urinals with high-efficiency models.
  • Replace old aerators and showerheads with newer, low-flow models.
  • Install a condensate return line on your boiler system if it does not already have one.
  • Regularly inspect, maintain and repair your boiler system to improve efficiency.
  • Consider engaging your local water company or an engineering firm to assess the condition and operation of your cooling tower which can account for a large percentage of your facility’s water consumption.
  • Use ice machines with air-cooled instead of water-cooled condensers and that are energy-efficient flake or nugget machines instead of cube ice machines.
  • Always run full loads of laundry.
  • Install aerators on kitchen sinks to reduce water flow to 2.5 gallons per minute or less.
  • Install pre-rinse spray valves that use 1.6 gallons per minute or less to rinse dishes.
  • Use boilerless steamers that consume less than 3 gallons of water per hour.
  • Install steam doors on dishwashers to reduce evaporation.
  • The Environmental Protection Agency maintains a list of WaterSense labeled products that can help you reduce water use while achieving exceptional performance.

2. How can I reduce outdoor water use at my facility?

  • Avoid watering during the hottest parts of the day.
  • Examine your irrigation system to ensure the even distribution of water to avoid over or underwatering of areas.
  • Regularly adjust your water schedule as weather conditions change throughout the year.  Consider installing watering control systems that use weather or soil moisture information to deliver irrigation according to plant requirements.
  • Use rain, freeze and wind sensors to interrupt irrigation during unfavorable weather conditions.
  • Watering deeply and less frequently may be more efficient and help your plants develop deeper roots than more frequent, light watering.
  • Consider retrofitting a portion of your system to use drip irrigation for trees, shrubs or plant beds.
  • Consider Xeriscaping (a term coined by Denver Water in 1981) to create a landscape of low water use plants that are compatible with Colorado’s semi-arid climate.  The seven principles of Xeriscaping include:
    • Planning and designing
    • Limiting turf areas
    • Selecting and zoning plants appropriately
    • Improving the soil
    • Using mulch
    • Irrigating efficiently
    • Maintaining the landscape
  • Use water-efficient landscapes with native plants that require little or no supplemental irrigation.
  • Always attach shut-off valves to handheld hoses.
  • Alternate turf mowing setting between low and high levels to encourage deeper root growth to allow for less watering.
  • Stop using water to clean sidewalks, driveways, parking lots, tennis courts and pool decks.
  • Make sure your irrigation water is reaching your plants and not ending up on artificial and impermeable surfaces.  In particular, eliminate small strips of grass wherever possible as they are hard to maintain and water efficiently.  Uses bushes, mulch or hardscapes instead.
  • Incorporate hydrozoning to group plants that have similar watering requirements.
  • Convert high water requiring turf types such as Kentucky bluegrass to low water turf grasses such as buffalo grass.
  • Mulch landscaped beds to reduce evaporative losses.
  • Convert turf to rock gardens or other non-water requiring landscape features.
  • Recycle grass clippings into the yard to help retain soil organic matter and to increase water retention.
  • Consider adding organic matter, such as compost, to the yard to increase water retention and to reduce deep percolation water loss to the underlying aquifer.

3. Where can I find more details about best management practices for water efficiency?

4. What should I consider when retrofitting my water heating system?

  • ENERGY STAR® maintains a list of efficient water heating products that may be applicable to your project.
  • Avoid overheating your water.  Most hot water applications only require water temperatures between 110°F and 140°F, so check the setting on your water tank.  Overheating water by as little as 10°F can cost you hundreds of dollars per year if you use a lot of hot water.
  • The Department of Energy’s Building Technologies Program provides information and recommendations on technologies that can be used to heat water efficiently in commercial buildings including:
    • Most commercial water heating uses storage water heaters that use gas, oil or electricity and release hot water from the top of the tank on demand, replacing it with cold water on the bottom as needed.  The constant heating of water in these tanks can waste energy even when no hot water is demanded.
    • In selecting a new water heater, you should consider:
      • Required capacity:  The first-hour rating (FHR - how much hot water the system can deliver during a busy hour) is a more important figure for properly sizing your system than the storage tank size.  Gas heaters have higher FHRs than electric heaters of the same storage capacity.
      • Rating efficiency: Use the water heater’s energy factor (EF) to select the most efficient water heater that meets your criteria.  Higher EFs indicate more efficient water heaters.  Ranges are typically:
        • Electric resistance water heaters = 0.7-0.95
        • Gas water heaters = 0.5-0.65
        • High-efficiency condensing gas water heaters = 0.9-0.95
        • Oil heaters = 0.7-0.85
        • Heat pump water heaters = 1.5-2.0
      • Compare costs: Use life cycle costing techniques to evaluate potentially higher initial cost sytems that may reduce operational energy costs and have longer lifetimes before replacement.
    • Consider installing drainwater heat recovery systems that can save energy by using the heat in hot water that would otherwise go down the drain to pre-heat incoming water for the water heater.

    • Heat pump water heaters can reduce energy consumption by up to 60% compared to conventional water heaters by extracting heat from indoor air, exhaust air or outdoor air and delivering it to water.  Commercial buildings that are good candidates for the use of heat pump water heaters include:

      • Laundries
      • Restaurants
      • Hotels and motels
      • Health clubs
      • Buildings requiring pool and spa water heating
      • Schools
      • Multifamly housing, and
      • Any facility where the cost of conventional water heating is high
    • Demand (tankless) water systems only heat water when needed avoiding heat loss due to storing hot water, but the rate of heated water flow can be limited.  Demand systems can be installed centrally or at point of use for boosting hot water levels of remote facilities or rooms.  The largest units could provide the hot water demand for a small commercial building.
    • More than 200,000 commercial solar water-heating systems have been installed in the U.S.  By reducing the amount of heat required by conventional water heating, solar water-heating systems can reduce the electricity or fossil fuel consumption of the water-heating system by up to 80%.  Climate and building load conditions will determine the appropriateness of these systems for an individual facility.

5. Are there any incentives or rebates available to help offset the costs of my water system upgrades?

Incentives and rebates may be available to help offset the costs associated with auditing or retrofitting your water system to make it more water and energy efficient.  Use the Energy Action Planner to look for opportunities available in your area.