ThermostaticMixing Valvetap

Harvested rainwater is typically used in non-potable applications but can meet potable standards with additional treatment. For potable systems, a licensed operator must maintain the system to ensure that it continues to produce water at a quality fit for human consumption. Additional considerations and components more specific to potable systems are shown in Table 2.

ThermostaticMixing Valve15mm

Mixing and tempering valves are designed to blend hot water with cold water to ensure a constant, safe outlet temperature. They are utilized in residential, commercial, and institutional applications where controlling water temperature is critical to reduce the risk of scalding, thermal shock, and Legionella growth.

Ensure dosing intervals are set as needed to sufficiently disinfect the amount of water processed through the system. Ongoing monitoring is essential to achieving this requirement.

Replace equipment such as ultraviolet (UV) lights at the end of their life. A UV lamp typically lasts about on year, and its effectiveness begins to diminish as it ages.

Thermostaticmixing valve temperaturesetting

Ceramic and titanium plates, fuses, and filters in ozone generators may need to be cleaned or replaced. Consult manufacturer specifications for frequency of maintenance.

Ensure controls operate as intended, visually confirm response to control commands. Request manufacturer maintenance as needed to repair any controls issues.

ThermostaticMixing Valve22mm

Follow manufacturer operation and maintenance guidelines for alternative stand-alone power supplies (e.g., solar photovoltaic panels).

Note: If there are large variations in rainfall throughout the year, a larger tank may be necessary to store rainwater during wet months for use during drier months. Additional treatment may be necessary to maintain water quality. In addition, it may be advantageous to compare weekly precipitation to weekly demand to get a more precise picture of the availability of rainfall to meet the water requirements of the application.

Infrequent blowdown may be needed to remove sediment from the bottom of the tank. If filters are regularly maintained, sediment accrual should be minimal (2 mm to 2 in. per year).

Thermostaticmixing valvehow it works

Harvested rainwater can provide a source of alternative water to federal facilities. Alternative waters are sustainable sources of water, not supplied from fresh surface water or groundwater, that offset the demand for freshwater. Rainwater harvesting captures, diverts, and stores rainwater from rooftops for later use. Typical uses of rainwater include landscape irrigation, wash applications, ornamental pond and fountain filling, cooling tower make-up water, and toilet and urinal flushing. With additional filtration and disinfection, harvested rainwater can also be treated to potable standards to supplement municipal potable water supplies to facilities.

Inspect potable water supply connection and backflow preventer and ensure that connections are in good condition without leaks.

Rainwater harvesting systems require regular operation and maintenance. Generally, the components of the system are made to last with regular upkeep, and manufacturers will often provide several years of warranty, anywhere from 15 to 30 years for storage tanks and pipework, and typically two to 10 years for pumps.

Table 1 lists the recommended operations and maintenance (O&M) actions for the major components. These actions should accompany actions recommended in manufacturer materials specific to the installed equipment.

The Federal Energy Management Program (FEMP) identified rainwater harvesting systems as an alternative water technology that is relevant to federal facilities, is commercially available, and may offer an opportunity to offset freshwater use. This technology review is intended to provide agencies with key information to deploy rainwater harvesting systems.